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Camera Lenses Bokeh
Camera Lenses Bokeh
A Distracting Zoom Lens Example of Bad Bokeh
Photo Courtesy of Luis Lopez Penabad - Thank You! (see posting)
Related Links:
Bokeh Explained (Ken Rockwell) [9/2002]
Bokeh in Pictures (Mike Johnston) [4/2004]
Bokeh Test Images (11/2003)
Comparison of 500mm mirror vs 300mm+TC lens bokeh
Guy's Bokeh Page and Sample Photos
Harold Merklinger - Bokeh Examples
Harold Merklinger's Technical View of Bokeh
(Photo Techniques Mag. May/June 1997)
Minolta Lens Bokeh Examples [12/2000]
Nikon Lenses Bokeh
Photonet Bokeh Discussion Thread
Vincent Chan's Bokeh pages
Introduction:
Bokeh is derived from a Japanese term referring to the
appearance of out-of-focus highlights as rendered by various lenses. This
term is new to many photographers, having been most recently popularized
in the USA by some articles (e.g., Photo Techniques Magazine
May/June 1997
- see links to PDF file by Harold Merklinger above). But bokeh is a term
that has been in use for decades to describe a real and easily
perceived photographic effect.
Bokeh falls into the category of subjective lens factors, meaning
we don't have any precise (objective) way of measuring people's
reaction to lens bokeh using
instruments or other measurements. While we can measure the
out-of-focus blur as intensity curves for various lenses, it is harder
to understand how they will impact our subjective reactions to the
photographic results. For this reason, different people will
respond differently to this aspect of lens performance, based on their
personal subjective reactions to the out-of-focus lens highlights. So
terms like "good bokeh" and "bad bokeh" have a subjective element in them
too. So don't be surprised to see disagreements about the bokeh of various
lenses, even between experts!
Thanks to Luis Lopez Penabad, the photo at top illustrates "bad bokeh"
from a small section of a photograph. Notice that the head is in sharp
focus, while the background out-of-focus highlights ("bokeh") are rather
distracting (as noted in posting). You can see the
bright halos and center dark rendition of this particular zoom
lens.
If you have used a mirror lens, you may have experienced the even
more distracting characteristic "donut" shaped highlights (to my
subjective tastes) of mirror lenses. This donut shape is due to a central
reflecting mirror in these compact mirror lens designs which blocks light
from the center of the lens. So you get an even more pronounced
"donut" highlight that can be quite distracting to many viewers. For this
reason, I prefer glass telephoto lenses over
mirror lenses mainly for their better bokeh (and higher contrast).
Sometimes a bad lens may have good bokeh. Many older lenses designed and
built in the 1930s suffer from various degrees of lens aberrations
(e.g., Leitz rangefinders, later Canon RF
etc.). Yet
many photographers praise these same lenses for their excellent bokeh,
identifying a "plastic" or "three-dimensional" quality to the rendition of
images. The spreading of out-of-focus highlights blurs the background in a
pleasing way without distracting attention from the main subject. You will
find similar praise for certain 35mm SLR lenses in the various postings
below too. Many times, photographers will prefer a lens with better bokeh
over a technically sharper or slightly better corrected more modern lens.
Various manufacturers have even introduced lenses with a variable degree
of control over lens aberrations (especially spherical aberration), such
as the Nikon 105mm DC and 135mm DC or defocus control lenses. Thanks to
some moving lens elements inside these lenses, you can vary the out of
focus effects in the background (or foreground) to produce pleasing
portraits, including a soft focus effect on the
main subject if desired. Usually, these specialty lenses are produced in
short telephoto focal lengths for the needs of soft focus portraiture,
where such controls provide a useful and precise control over these
subjective factors.
Some folks claim that the quality of the bokeh is determined by the number
of diaphragm blades. I believe this is not technically correct
nor a full explanation of why different lenses with the same
number of diaphragm blades have such radically different bokeh. Rather, I
think that older lenses historically had more blades in their construction
than many newer lenses, as well as greater degrees of under or
over-corrected spherical aberration. So casual comparison with today's
fewer diaphragm blade lenses (with cheaper construction design and much
lower cost in inflation adjusted dollars) suggested that the older lenses
(with more diaphragm blades) had better bokeh to many users. But since
some modern and older lenses with fewer diaphragm blades have good bokeh
too, this factor as a "cause" or determining factor for good bokeh is in
doubt in my opinion.
Lens designers can control the bokeh of their lens designs. One of the
nice factors about the rising interest in bokeh is that it may encourage
design of lenses with better or smoother bokeh effects. Unfortunately,
many photo magazines emphasize the much easier to measure lens resolution
and contrast factors. While important, a lens with better bokeh will often
be preferred for subjects like portraiture where you want to isolate your
subject from their background or foreground. Good bokeh lenses without
distracting out of focus highlights makes such portrait photos easier to
make.
So why is bokeh important? Bokeh is important because it controls a
significant factor in how your lenses render the out of focus areas of
your photographs. Some pro photographers spend large sums on defocus
control and soft focus pro lenses to gain control over these
factors. Others of us test a wide variety of lenses, and hold onto those
which show good bokeh based on our subjective opinions and style of
photography. In the end, you have to learn about bokeh and learn to
recognize these factors if you are to control this subjective lens
performance factor in your photography.
Date: Sat, 28 Oct 2000
From: Luis Lopez Penabad luislopez@earthlink.net
To: rmonagha@post.cis.smu.edu
Subject: bad bokeh example
Dear Sir:
Thank you for your interesting forum. Until a few years ago I have been
doing family portraits with a Canon FD 135 2.8 lens. It produced
beautiful out of focus backgrounds. A few months ago my equipment was
stolen and I changed to an EOS system. I bought a 4 single focal lenses
(20, 28, 50 and 100 Macro) along with 2 zooms the 80-200 f:4 L and the
28-105 f:3.5-4.5.
The 28-105 is a nice lens: compact, good zoom range and reasonable
sharp. Unfortunately it has a very bad bokeh. Please take a look at the
enclosed picture taken with this lens, the out of focus highlights
appear as bright halos with dark center forming a very noticeable
pattern. This is a low resolution scan but in the real velvia slide it
is very distracting and annoying.
Please feel free to use this image in your page as an example of bad
bokeh and to reproduce this comment in part or whole.
Thank you
Luis Lopez
From Nikon Digest:
Date: Tue, 14 Jul 1998
From: "Roland Vink" roland.vink@ait.ac.nz
Subject: All about Bokeh
Hello all,
A while ago there was a discussion which touched on bokeh - which has to
do with parts of the image which are out of focus.
I think we can all agree that most Nikon lenses are pretty sharp (assuming
they are in focus and the camera is steady!) Photography and the
related arts are unique in that parts of the image can be out of focus.
Paintings for example, can be drawn with everthing equally sharp.
Therefore the concept of "in focus" and "out of focus" are important to
photography and have a big impact on our images, even if we are not fully
conscious of it.
Bokeh is obviously influenced by a number of factors. The aperture
controls the size or amount of blur. Stop down and the blur decreases and
the depth of field increases. Open up and the blur expands and softens.
The shape of the aperture also affects bokeh. Out of focus points of
light, such as the sky filtering through trees or distant city lights will
take on the same shape as the aperture opening.
You can tell quite a lot about the lens by studying the the bokeh.
Highlights which are perfectly round in the center of the image and become
pointed ellipses towards the corners indicate the lens was used wide open,
and the lens has some physical vignetting (all lenses have this wide
open). If the highlights are polygons, the lens was stopped down and you
can count how many aperture blades it has, and maybe even guess which lens
was used!
It may surprise some to find that not all bokeh is created equal, even
with two lenses of the same focal length and aperture.
A lens may project hard edged blurs producing abrupt transitions from
light to dark, poorer definition to out of focus objects and doubling of
out of focus lines. Or a lens may produce soft edged blurs giving smooth
even transitions in areas of contrast.
A lens usually produces hard edged blur in the background and a softer
effect in the foreground if spherical aberations are overcontrolled as in
most Nikkors. A lens projects soft blurs in the background and a harder
effect in the foreground if spherical aberations are underercontrolled.
Leica, Zeiss, Canon and Minolta generally design for this though some
Nikkors like the 85mm/1.4 AF-D are designed for better background
definition, and the DC lenses allow the photographer to manipulate the
defocus blur characteristics.
With this in mind, I decided to see how some Nikkor portrait lenses
compare. These are often used at wide apertures, so the bokeh
characteristics could be very important. My test consisted of shooting a
pile of boxes on the side of the street from a low angle so the street
lights, trees and buildings across the street were visible in the
background. Each lens was shot wide open, stopped down one, and two stops.
The results on the basis of this very limted test:
AIS 85/2. Wide open this lens produced quite hard edged blur in the
background, which softens somewhat at f2.8 and f4. Perhaps that is
why this lens never gained a good reputation. However at close focus
distances, due the fast aperture, this lens is capable of producing
wonderful effects. If the background has low contrast, this is still a
great portrait lens.
AIS 105/2.5. This lens produces a neutral - soft effect in the background.
Wide open it is a wonderful portrait lens.
AIS 135/2.8. This lens is also produced very nice effects in my test,
equal to the 105/2.5. This may partly be due to the longer focal length
which tends to blur out the backgroud more. I've used this lens quite
extensively and sometimes the effect is not so smooth. I'd say overall
this lens has neutral bokeh, helped by the longer focal length.
AF 105/2.8 micro. Produces a slight hard edged effect in the background
and is smoother in the forground. The AIS 105/2.5 is definitely better if
you want nice bokeh.
AIS 105/4 micro. This lens is probably too slow to be effective for
portraiture, but it was available so I tried it. It's effects were similar
to the AF micro lens, with distinct hard edged blur in the background.
Sorry I didn't have any of the AF 85mm lenses or DC lenses to try out!
In terms of sharpness and contrast, all these lenses were excellent even
wide open, although to be honest, I was shooting in favorable conditions
and my slide projector does not allow me to review my pictures very
critically!
Regards from Roland.
From: Peter Olsson Peter.Olsson@sb.luth.se
Subject: Aperture vs out of focus-highlights
Date: 1998-07-15
I am an amateur photographer and mainly use my Hasselblad camera for
portraits outdoors, in available light, sometimes with fill-flash.
Problem is, I don't like the pentagon-shaped out of focus-highlights for all
apertures but wide open. I like the square-format but I would
prefer lenses with more aperture-blades, to give more of a circular
rendition of out of focus bright points. Are the Rollei-lenses better
in this respect or do they also produce the pentagon-shape? (I don't
ask about Bronica only because the used-market in Sweden is too small).
From: madmat@ix.netcom.com Matthew Y. Hayashibara
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: Wed, 22 Jul 1998
"F. Javier Heredia"
heredia@eio.upc.es wrote:
>Hi to all!
>
>I'm sorry, but recently I have found the word "bokeh" in several
>photo DL and NG, and I have no idea of what it is. I think it
>is something related with the quality of the foreground and
>background area out of the depth of field region.
>
>Can anybody explain me what "bokeh" is?
Shape of the lens apereture in relation to a perfect circle. If you've
got more blades in the diaphragm, the shape of the apereture more
closely approaches that of a circle, which results in those nice,
circular out-of-focus highlights. If you've got a six-blade apereture,
you get those ugly, artificial-looking hexagons.
It's interesting that in Photoshop, if you want to add intentional
artificial flare to a picture, some plug-ins let you choose the shape
of the highlights!
And of course, for those mirror (catadioptric) teles, you get the
donuts...
MadMat
From: yoshihiko@takinami.com (Yoshihiko Takinami)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: Thu, 23 Jul 1998
Hello,
"F. Javier Heredia" heredia@eio.upc.es wrote:
> I'm sorry, but recently I have found the word "bokeh" in several
> photo DL and NG, and I have no idea of what it is. I think it
> is something related with the quality of the foreground and
> background area out of the depth of field region.
>
> Can anybody explain me what "bokeh" is?
I suppose "bokeh" comes from a Japanese word of the similar
pronounciation. It means blured or faded images of out-of-
focus objects in photography.
# "Bokeh" also means senility, or in some cases a fool/idiot
# in disparaging manner.
Some Japanese manufacturer, I guess, started to say in mid 80s
that a beautiful bokeh, a qualty of out-of-focus image, is very
important as well as a sharp in-focus object in photography.
The first runner was Minolta. This is why we use Japanese word
for such a concept, I suppose.
In general, it is said that the quality of bokeh is closely
related in a certain optic with the number/shape of diaphragm
blades and the position of them.
The best position of diaphragm should slightly varies when the
aperture is changed.
Hope this helps and sorry for my poor English.
--
Yoshihiko Takinami
Osaka, Japan
yoshihiko@takinami.com
From: "Yuusuke Wada" kk-wada@gemini.bekkoame.ne.jp
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: 23 Jul 1998
Well, we in Japan, use the word for the unfocused area
in photography. The foreground and background non-focused
sight and how much of DOF you can get.
BOKEH is also a slang for "absent minded idiot" in Japanese
as well.
....
From: "+ke Vinberg" avinberg@brio.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: Thu, 23 Jul 1998
The shape of the aperture is only part of bokeh.
The other part is the level of intensity in different parts of an
out-of-focus highlight. Say you have a pointed light source, and the lens is
focused at a different distance. Let's also for argument's sake say that
there is no aperture, the lens is wide open and round. The pointed light
source will be rendered as a blurred disc.
But there are different ways to render a blur.
- A neutral way would be a constant intensity across the disc, which would
give the look of a white disc.
- Then there is the "good" bokeh, where intensity increases towards the
center of the disc, leaving soft edges. The article mentioned that Leica
glass is known to have this kind of bokeh.
- Lastly, there is the "donut" bokeh, where intensity first increases and
then decreases in the center. This happens for mirror reflex lenses, but
also for lenses that are over-corrected for spherical aberration. This will
for example cause a line that is our of focus to be rendered as two lines.
- The intensity curve can of course be more complex.
None of the above is directly related to the shape of the aperture, the
assumption made was that the aperture is round (but a non-round aperture
will affect the rendering as well).
Japanese lens manufacturers seem to pay more attention to this lately.
Nikon, for example, has special 105 and 135mm "DC" lenses where the bokeh is
adjustable by adjusting the amount of correction for spherical aberration.
Also, the Nikkor AF 85/1.4D is supposedly designed with bokeh in mind. An
older design, Pentax SMC-M 85/2.0 is known to produce attractive highlights
for objects slightly out of focus, like in portraits.
I hope I got this right, please feel free to correct me.
Ake
niblue@my-dejanews.com wrote
>bokeh relates to the look of the out of focus areas in an image, and seems
to
>relate to how round the aperture in the lens is. Generally lenses with more
>aperture blades will have better bokeh.
>
>---Nile
From: joe-b@dircon.co.uk.com (Joe Berenbaum)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: Thu, 23 Jul 1998
> wrote:
>
>>Hi to all!
>>
>>I'm sorry, but recently I have found the word "bokeh" in several
>>photo DL and NG, and I have no idea of what it is. I think it
>>is something related with the quality of the foreground and
>>background area out of the depth of field region.
>>
>>Can anybody explain me what "bokeh" is?
>
>Shape of the lens apereture in relation to a perfect circle. If you've
>got more blades in the diaphragm, the shape of the apereture more
>closely approaches that of a circle, which results in those nice,
>circular out-of-focus highlights. If you've got a six-blade apereture,
>you get those ugly, artificial-looking hexagons.
>
>It's interesting that in Photoshop, if you want to add intentional
>artificial flare to a picture, some plug-ins let you choose the shape
>of the highlights!
>
>And of course, for those mirror (catadioptric) teles, you get the
>donuts...
>
>MadMat
I've heard this explanation about the diaphragm opening many times and
I don't think it is actually true. My Minox 35ML has reasonably
attractive bokeh (appearance of the out of focus areas of an image)
and it has only two diaphgragm blades! It does not appear to produce
unpleasant diamond shapes in the pictures. I have a 1959 50mm/2.8
Elmar (approx 15 aperture blades) and a current 50/2.8 Elmar-M (6
aperture blades). The bokeh is indistinguishable between the two. I
think the bokeh depends on the design of the elements of a lens, not
so much, and maybe not at all, on the design of the diaphragm.
Otherwise, all equivalent spec lenses would have similar bokeh wide
open, and this is very far from being the case. If you compare the
bokeh in wide open shots from a 50/1.4 Nikkor and a 50/1.4 Summilux,
you will see what I mean. There is a very visible difference. FWIW, I
have found the bokeh I prefer mostly in German lenses, but also in
Minolta lenses. I now use Minolta for my AF slr system and I couldn't
be happier. I can mix Minolta images with those taken with Leica
lenses and there is no obvious clash of image character.
Joe B. (remove ".com" for email)
From: "+ke Vinberg" avinberg@brio.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: Thu, 23 Jul 1998
Photo Techniques, May or June (July?) 1997.
Tom Rittenhouse wrote ...
>Yuusuke Wada (kk-wada@gemini.bekkoame.ne.jp) wrote:
>:
>: But I wonder why a such a word is being used around the world.
>: It's not like "tsunami" for "tidal waves", I think.
>:
>
>One of the photo magazines had an article about it about a year
>ago as I seem to recall. Ever since it gets mentioned about once
>a month on these rec.photo groups.
>
>Translation: Unfocused highlights. Not a very new concept.
>
>--
>Graywolf (Tom Rittenhouse)
From: "Yuusuke Wada" kk-wada@gemini.bekkoame.ne.jp
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: 23 Jul 1998
http://www.engr.uvic.ca/~vhchan/bokeh.html
check here!
The word is originally Japanese for blur and de-focused area.
From: AlanBall@my-dejanews.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: Fri, 24 Jul 1998
fredhess@wxs.nl wrote:
> .........
> I use for almost 25 years Leica-cameras. The choice for these cameras is
> dominated by the lens-quality and espacialy the "bokeh" of the lenses.
> Leica-R-camera's for wildlife-photography and Leica-M- and R-cmara's for
> photojournalism.
Not too sure about the "bouquet" origin of the word, as our Japanese posters
might confirm. Anyway, I have a problem with descriptions that end up giving
such or such a range of products some kind of systematic and recognizable
brand quality.
In my experience, some N lenses have a very harsh (angular) rendition of out
of focus portions of an image (50mm f1.8), and others have a 'mushier' one
(85mm f1.8). I used to have a CZ 50mm f1.4 and 85mm f1.4 which had that
'mushy' quality but also a 135mm f2.8 that did not have it at all. In some
slides shot with the G 90mm f2.8, I have a nice cottonlike background blur
but a radical straight dedoubling of shapes in the foreground blur. In my M
range, the 35mm f2 asph does not have that 'atmosphere' in the background
that my previous Summicron had, but the 50mm f2 'cron is cool in that
respect. The aperture of the 90mm f2.8 Elmarit has fewer blades than other
lenses mentionned here, which end up with geometric renditions of highlights
in the background, while the rest of the background is very smooth. And on,
and on, and on.
So, my point is that I would be very surprised if the opticians
systematically compute the "bokeh" parameter when they design a lens. This
might be the case on specific designs, usually marketed as such (portrait
lenses, etc), but seems to me more like an accidental result of the
integration of all the other corrective and optimisation parameters involved
in lens designing.
As you are well aware, benchmarking is an important issue in the
marketing of
lenses : the tests published by the specialised press or the MTF curves
published by the manufacturers usually concentrate on the measurement of
definition and contrast. Notions like vignetting, distortion, colour balance
are also tested and measured and argued about. If bokeh was something centra
to the designer's priority list, it would have been agressively marketed as
well since a very long time. It has only started to be mentionned during the
last 4-5 years and the tweaking of spherical corrections specifically aimed
at changing the background rendition is also a recent functionnality (DC
lenses).
As a conclusion, I would guard myself and others from establishing
generalisations based on brand in that field of optical performance as well.
But I would also like bokeh to become an integral part of the description of
the performance of any lens. In my photography, bokeh is somewhat more
crucial than distorion or vignetting. So the question is: can it be measured
?
Alan
Brussels-Belgium
From: "+ke Vinberg" avinberg@brio.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh"?
Date: Fri, 24 Jul 1998
So the question is: can it be measured?
Bokeh can indeed be measured, but evaluating the results might not be
trivial. This measurement is described in the May(?) 1997 issue of Photo
Techniques.
The method of measurement is to plot the intensity of an out-of-focus
highlight (small light point against dark background) across and
intersection of the highlight. This will render a bokeh curve for that
specific lens, at that specific focus distance, and with the highlight at
that specific distance. A measurement in the center of the image will also
be different from a measurement at the corner of the image, due to light
falloff, internal vignetting, and other optical imperfections.
There are obviously a lot of parameters here, so it is not possible to
quantify bokeh in one quantitative measurement. Rather, curves could be
measured at predefined focus- and object-distances at specific apertures.
Alan mentioned that some of his Leica lenses give "mushy" out-of-focus
highlights. An intensity curve that has a peak in the middle will likely
give more "mushy" highlights than a curve that is flat, or one that has
dip in the center.
It appears common for lenses with good background bokeh to have poor
foreground bokeh. The Nikkor DC lenses allow the background bokeh to be
improved on expense of the foreground bokeh, and vice versa.
Ake
From: "Michael A. Covington" covington@mindspring.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Tue, 28 Jul 1998
Yes, it definitely is. My own theory is that (1) the human brain is very
good at interpreting out-of-focus images from the eyes, and (2) if the
out-of-focus images produced by a lens resemble those produced by the eye,
the "bokeh" will be pleasing and the focusing error will look less severe
than it is.
As you note, "good bokeh" requires radial and tangential aberrations to be
about the same (otherwise you get asymmetrical blurs near the edge of
field). Here are some other requirements of "good bokeh" as I understand
it:
- Round diaphragm. (I have an old Schneider lens with a square
diaphragm...)
- No central obstruction (mirror lenses have very unnatural bokeh).
- Spherical aberration is tolerable and even beneficial. The human eye has
lots of spherical aberration and is good at correcting it in the brain.
Other thoughts, anyone?
--
Michael A. Covington / AI Center / The University of Georgia
http://www.ai.uga.edu/~mc http://www.mindspring.com/~covington
From: AlanBall@my-dejanews.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Wed, 29 Jul 1998
>
> As you note, "good bokeh" requires radial and tangential aberrations to be
> about the same (otherwise you get asymmetrical blurs near the edge of
> field).
Symmetrical or asymmetrical is not really the issue I find. What I
consider as
unpleasing bokeh is the "harsh" dedoubling of lines in the background.
What I
consider as pleasing bokeh is the "mushy" mix-up of background elements.
> Here are some other requirements of "good bokeh" as I understand
> it:
> - Round diaphragm. (I have an old Schneider lens with a square
> diaphragm...)
Round diaphragm makes round highlights which might be more pleasant than
polygonal highlights. But I own lenses which I find have fantastic bokeh with
polygonal diaphragms. The best example for me is the current 90mm Elmarit-M.
Anyway, I can see no negative impact of more blades on other performances and
therefore wish that the makers concentrated on 9-10 blades designs...
> - Spherical aberration is tolerable and even beneficial. The human eye has
> lots of spherical aberration and is good at correcting it in the brain.
Yes, I think that is a central point. Which is why I believe bokeh is NOT
computed in most lens designs: lower spherical corrections have a negative
impact on other benchmark results, which are the results published in
specialised magazines and that everyone uses in the marketing
departments. In
order to sell lenses, everybody argues on lines per millimeter, contrast,
etc. It is VERY recent that some makers use the quality of 'background blur'
to sell a lens. The best recent example are both Nikkor DC lenses.
So, my point is that good bokeh does exist but that it was not meant to
exist: some lenses have it by accident (lower correction of spherical
aberrations), some do not because they are 'overcorrected'. If it was not an
'accident', the suppliers would have used that element of description to
counterbalance 'average' test results on other optical benchmarks. I believe
that bokeh is one of the reasons some users find stellar qualities to lenses
that perform only in an average way on the other benchmarks. The name Zeiss
comes to my mind when I state this. I wish the specialised press included
'bokeh' in the lens tests: it is usefeul information. I think we will read
much more about this in the future.
Alan
Brussels-Belgium
From: joe-b@dircon.co.uk.com (Joe Berenbaum)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Tue, 28 Jul 1998
"Pataki, Ferenc" fpataki@geometria.hu wrote:
In recent years I have made bokeh pretty much the highest priority,
allowing for choosing from lenses that are sharp and contrasty in the
first place, of course. Leica lenses (up until recently, anyway) are
really good in this respect, Nikon have designed a lot of lenses that
seem to ignore the concept of bokeh altogether and Canon seem to be
aware of it but it isn't at the top of their list. Minolta seem to
accord bokeh high priority in lens design; after using Nikon (mostly)
and Canon AF systems I have finally settled on Minolta for my AF
needs, and Leica for the rest.. The bokeh of Minolta lenses resembles
that of Leica lenses quite closely.
From: cu050@cleveland.Freenet.Edu (David L. Bernard)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: 29 Jul 1998
I design my images to be in focus, and could care less about any parts
that can't be in focus. I don't believe in bokeh, I think it's a bunch
of hooey, and irrelevant. Else, why not a portfolio with all images out
of focus? I tend to suspect it's an emperor's new clothes issue, and at
some point in another twenty years we'll all have a good laugh on how we
were all taken in. Sort of like, how we all know [name your favorite]
camera maker makes the best lenses, and although they may not be the
best in any test known to man, we devise all sorts of contorted,
immeasurable descriptions so at to yet claim superiority, without
deigning to resort to quantifiable description.
(It's been a rough day!)
From: "+ke Vinberg" avinberg@brio.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Tue, 28 Jul 1998
Yes, it must have been a rough day, but that's OK.
Some photographers like the "f/64" method - everything sharp - whereas some
people like to play the depth-of-field game. I like both. Landscapes and
often architecture benefit from small apertures, whereas candid shots with
longer focal lengths benefit from a more shallow depth of field to isolate
the subject.
There is nothing new about bokeh except possibly the word. And the relevance
of out-of-focus characteristics will hardly go away with time.
Some of my photos that I like the most were taken with a Pentax-M 85/2 (sold
it a few years ago). The articles about bokeh in Photo Techniques last year
made me understand just why I liked that lens, the difference when comparing
to images from my Nikkor 85/1.8D was quite obvious (sold that one too, got
the 85/1.4D instead). The 1.4D has a softness to the near background bokeh
that the 1.8D just doesn't have. Both lenses are quite sharp.
BTW, bokeh is a measurable property, see Photo Techniques 5/97 for articles
and plots of intensity curves for out-of-focus highlights.
BTW(2), there is a good description of the adjustable bokeh of the AF
Nikkors:
Nikon Japan describes this (in English), look at
http://www.klt.co.jp/Nikon/PPD/Lineup/Lenses/Guide/opt_tech2.html#AFDC
Regards,
Ake
From: steven T koontz skoontz@mindspring.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Thu, 30 Jul 1998
David L. Bernard wrote:
>
> >DB> I design my images to be in focus, and could care less about any parts
> >DB> that can't be in focus. I don't believe in bokeh, I think it's a bunch
> >DB> of hooey, and irrelevant. Else, why not a portfolio with all images out
>>DB> of focus?
> >Bokeh is hardly an "Emperor's new clothes" issue !! Bokeh simply refers to
> >the character of the areas of a photo that are not in focus, and lens design
> >creates noticable differences in the rendering of highlights in these areas.
>
> What some may call lack of control of out of focus area I call lack of
> control over focus area. I don't think 'out of focus' and 'bokeh' are
> the same thing; the latter refers to a semi-mystical aesthetic
> perceivable to some within the out of focus area.
>
Sorry but it's not mystical or "perceived to some" but a fact of
photography.. While you may chose to ignore it, to alot of
photographers, it makes of breaks an image.. Anyone can stop a lens
way down and get everything in focus (to an extent) and eliminate this
"problem", but most interesting shots have the subject separated from
the background and "ugly bokeh" will ruin the picture.. I have several
macro lenses and one stands out because of the wonderful bokeh it
has.. Not the resolution..
Alot of people feel like they can measure everything about a lens
scientifically and prove one is "better" than another.. Just doesn't
work like that.. At least to me.. there are things more important than
resolution and sharpness . I'd much rather have a good high contrast
lens with nice bokeh than a super sharp one with ugly bokeh..
--
steve's photography & Z car stuff @ http://www.mindspring.com/~skoontz
skoontz@mindspring.com
From: steven T koontz skoontz@mindspring.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Thu, 30 Jul 1998
John Sparks wrote:
>
> steven T koontz (skoontz@mindspring.com) wrote:
> >... I have several
> >macro lenses and one stands out because of the wonderful bokeh it
> >has.. Not the resolution..
>
> I'll bite, what is the macro lens with good bokeh and what others have
> you tried that are not so good.
Well, the lenses I'm refering to are the (both olympus zuiko lenses)
50 f2 macro (I like that one) and the 80 f4 macro belows lens.. While
it's not "plain awful" bokeh, it's not as nice as the 50 f2 while the
80 is sharper close in.. I have to assume that the lens design causes
this.. Actually that 50 f2 is one of my favorite lenses for that
reason...
--
steve's photography & Z car stuff @ http://www.mindspring.com/~skoontz
skoontz@mindspring.com
From: joe-b@dircon.co.uk.com (Joe Berenbaum)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Wed, 29 Jul 1998
>Hi, That is an interesting statement. As a Leica M user and really
>appreciative of the bokeh quality of some of my M lenses, I wish I could find
>them in the (affordable) SLR world as well. I come mainly from a Nikon
>background and tend to agree with the idea that nikkor lenses are often
>'harsh' in the background (would like to know more about the DC lenses
>though). I've used Zeiss/Contax and was satisfied regarding that issue but
>got fed up with reliability problems. Hardly know Minolta. So, out of
>curiosity, what Minolta lenses are you using and which qualify the most to
>'Leica bokeh' ?
>Thanks beforehand
>Alan
I first noticed this with an old 58/1.4 PF non-meter-coupled Rokkor I
had some years ago when I was a Minolta MF user. I was not very
knowledgeable then and I liked the smooth look of the out of focus
parts of the pictures very much, but I didn't realise that one day
that look would define lens quality for me! Nowadays I use the
following Minolta lenses;
MF: 24/2.8, 58/1.2, 135/2.8,
AF: 24/2.8, 28/2, 50/1.7, 100/2, 135/2.8, 24-85 type 1, 35-105 type 1.
The most obvious Leica-look bokeh appears at wide apertures with the
faster or longer prime lenses. Notably wonderful effects have been
observed with the 50/1.7 (used close up, with a distant background,
amazing child portraits), 100/2 and the 135/2.8 when used for
portraits. The 28/2 has soft bokeh and is thus very different to the
28/2 mf Nikkor I had before. Now that I stop to think about it, since
I saw the results from the 100 and 135, I have been leaving some very
excellent Leica equipment in its drawer. It will come out again,
obviously, but I am very pleased to be able to get that kind of look
with lenses that autofocus and I expect to be doing proportionally
more Minolta portraits for this reason. I like to catch spontaneous
and fleeting expressions at full aperture and the Minolta AF system
does this where a manual focus system, however good the lenses are,
can't. .
I have a shopping list of other Minolta lenses but no money to buy
them right now. At some point I want to get the 35/1.4 and 85/1.4 but
for some reason they seem to want more money for those lenses...;-)
Joe B. -please remove ".com" for email
Thinking is good -think something today
From: joe-b@dircon.co.uk.com (Joe Berenbaum)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Wed, 29 Jul 1998
Wilfred Kazoks "wilfred"@alphalink.com.au(nospanM) wrote:
>I remember that the sales brochure for the Minolta HiMatic E and F from
>the mid 70's made a very prominent feature of the quality of the out of
>focus areas of the pictures the camera produced. The example
>illustration was an outdoor portrait with the strongly blurred
>background being a tree with light patches where sky showed throught the
>leaf canopy. The minolta did produce a (to me) more pleasing picture and
>since reviewing the brochure a few years ago this aspect of lens design
>has been something I consider. I didn't know it had a name though. If I
>recall the cameras aperture diaphram was also the leaf shutter and it
>was this that was the beholder of the clever design claimed to produce
>the effect. It was only a sales brochure though aimed at the P$S crowd.
>Regards Wilfred
It's funny- now that I am aware of this consideration, I notice other
references to bokeh, direct or indirect, in Minolta leaflets. If you
look at the cover of the brochure for the 9xi- it is covered with soft
green bokeh! It's just the soft blurred look of distant foliage, or
something like that. But it makes the point. And there are five
pictureso f various sizes in that brochure that clearly demonstrate
the soft bokeh that the lenses in question produce. Once you notice
this it is unmissable.
Joe B. -please remove ".com" for email
From: Wilfred Kazoks wilfred@alphalink.com.au
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Wed, 29 Jul 1998
I remember that the sales brochure for the Minolta HiMatic E and F from
the mid 70's made a very prominent feature of the quality of the out of
focus areas of the pictures the camera produced. The example
illustration was an outdoor portrait with the strongly blurred
background being a tree with light patches where sky showed throught the
leaf canopy. The minolta did produce a (to me) more pleasing picture and
since reviewing the brochure a few years ago this aspect of lens design
has been something I consider. I didn't know it had a name though. If I
recall the cameras aperture diaphram was also the leaf shutter and it
was this that was the beholder of the clever design claimed to produce
the effect. It was only a sales brochure though aimed at the P$S crowd.
Regards Wilfred
From: rpn1@cornell.edu (Neuman-Ruether)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Thu, 30 Jul 1998
wkato@aol.com (WKato) wrote:
>Maybe this problem can best be phrased in the obverse, i.e. "ugly bokeh" I
>don't know what it is when I see it but when it's bad, it's ugly. Examples
>would be double out of focus lines (for hard edged objects), the donuts from
>mirror lenses of specular out of focus highlights, and other ugly things that
>are hard to define. I recall leaves in the backround that don't just look like
>out of focus leaves but they seem to want to take on a life of their own and
>look like hard edged green amoebas. The "ugly bokeh" joins separate elements
>that were never meant to be morphed together. A branch and a leaf sort of grow
>together with a semi-hard edge to form a third unworldly object, the green from
>the branch infusing into the branch and the brown from the branch into the
>leaf. Now that's "ugly bokeh."
OK, I can't resist responding... Let's hear it for "bad" bokeh! ;-) On the
one side, one may be interested in photographing in a way that may be
condidered good "recording" of what was in front of the camera, in which
case "good" bokeh may be desireable... (though some of us would insist
that photographs make terrible records of whatever is in front of the
camera, so the rendering characteristic of bokeh may contribute little to
enhancing the veracity of the photographic record...). On the other side
is the concept that photography is a graphic medium, and is little more
than the arrangement of tonal and color variations. From this point of
view, "bad" bokeh may be good bokeh, since it makes possible some kinds of
imaging that don't work well using lenses that have "good" bokeh... For
examples of these, I refer you to my web page, first and fifth photos in
"Aht Fotoz - art photography", and most of the photographs in "Changing
Showz - Sun-Plants". The double-edging of features in out of focus areas,
and the "harder" textural quality in out of focus areas serves to
graphically integrate the photographs better than if there were more
differentiatiation between what is in and out of focus. (BTW, related to
this is the fact that "bad" bokeh lenses can appear to be both sharp and
have greater than normal DOF [soft lenses also have extra DOF too...;-]).
I prefer lenses that render with snap and contrast in the out of focus
areas - lenses with "bad" bokeh...
David Ruether
ruether@fcinet.com
rpn1@cornell.edu
From: "Fred Whitlock" afc@cl-sys.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Fri, 31 Jul 1998
Hear Hear. I couldn't agree more. After all, the areas of a photograph
that are out of focus should look, well, out of focus. If the out of focus
areas in a photograph draw one's eye away from the intended main subject,
then, perhaps there are other problems with the photograph such as
composition. Yes, I understand that sometimes the main subject is rendered
out of focus on purpose but I trust you understand what I mean. I have
photographs with areas in or out of focus that I wish went the other way.
But concerning oneself with the visual "quality" of the areas out of focus
is missing the main compositional point.
I marvel at how some photographers rate a lens based on "bokeh" above its
optical performance for a sharp subject. A good example is the old Leitz
Summar lens for the Leica cameras. Leica hasn't made very many bad lenses
but this is one of them. It is just plain soft. I've heard Leica
photographers defend this lens based on "bokeh" and say that they prefer it
to a lens like the Summicron which is as sharp as a tack. Different
strokes, I guess.
Fred
Maplewood Photography
http://www.maplewoodphoto.com
From: kopitnil@my-dejanews.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Sat, 01 Aug 1998
Fred and David, you are two of the writers to this group whose views I have
come to respect the most. I will always stop to read the posts you make. But
on this matter, with you both, to a certain extent I respectfully disagree.
The out-of-focus areas are a part of the photograph. Therefore, for
better or
for worse, they are a part of the composition and the nature of them impacts
that composition.
The best example I can cite is the 50 mm f/1.4 Nikkor. It's a wonderfully
sharp lens closed down a stop or two. Several photographers who have shot
with the 50 Nikkor and 50 Leica Summiluxes (including Leica's new R system
50) have told me the Nikkor is sharper than Leica's offerings. But the
"bokeh" and tonal rendering of the 50 f/1.4 Nikkor have, to my my eye, ruined
more than a few photos I've taken with it.
Specifically, when photographing a multi-bulb ceiling lamp with the 50 f/1.4
Nikkor, background shapes were disturbingly hard-edged and graphic. The edge
of the bulbs transitioned abruptly into a muddy background. The lamp's
highlights were similarly hard-edged. Little detail was captured in the
shadow areas.
I photographed the same scene with the 85 f/1.4D Nikkor. That lens
produced a
photo where the out-of-focus bulbs almost melted into a smooth and richly-
colored background, with the lamp's highlights blending gently into the lamp.
The smoothness of the out-of-focus areas accentuated the sharpness of the
focused parts.
(I've since sold the 50 Nikkor and replaced it with a 35 f/1.4 Nikkor as my
mid- range fast lens. The 35, to me anyway, renders tonal ranges and "bokeh"
far more pleasingly.)
As David points out, those hard-edged out-of-focus elements can be used
graphically. But I find sharp focussed areas contasting against smooth
out-of-
focus areas more often useful in a composition.
I wouldn't argue that "bokeh" is more important than sharpness when
evaluating a lens. But I do consider it important. Because "bad bokeh" can
ruin a photo for me every bit as much as lack of sharpness.
Larry
From: "Fred Whitlock" afc@cl-sys.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Sat, 1 Aug 1998
>I wouldn't argue that "bokeh" is more important than sharpness when
>evaluating a lens. But I do consider it important. Because "bad bokeh" can
>ruin a photo for me every bit as much as lack of sharpness.
>
>Larry
Larry, I have no problem at all with disagreement and I'm quite aware of the
warm feelings some photographers have about "bokeh." But just like
audiophiles arguing about the relative sound of stranded vs. single
conductor wire, this is a matter of preference. There is no right or wrong
answer. My personal experience is that the lenses known to have good
"bokeh" (I used the Summar in my original post as an example) aren't usually
the last word in critical sharpness. I sold my 135 DC Nikkor partly
because of it's performance at wide apertures. It is designed around good
"bokeh" and even has adjustable "bokeh." I know there are a few lenses that
are known to have good "bokeh" and tack sharpness but these appear to be
rare. My preference, like David's, is to have critical sharpness. If you
can have both that's great, but if not, then it gets down to preference.
I don't argue that out-of-focus areas aren't part of a photograph. My point
was that, usually, my goal is have the viewer's eye drawn away from those
areas and toward the main subject. I don't suggest that I always succeed
but I can promise you I've never once concerned myself even a little about
the quality of out-of-focus areas-just their location and the amount of
out-of-focussedness (gads that's a terrible word.) I can always make a
photograph unsharp-if that's my purpose-even with a critically sharp lens.
But I can't make one sharp with a soft lens. Thanks for the post. Good
shooting.
Fred
From: jawalker@beckman.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "bokeh" - it is a lens design issue !!!
Date: Fri, 31 Jul 1998
cu050@cleveland.Freenet.Edu (David L. Bernard) wrote:
> What some may call lack of control of out of focus area I call lack of
> control over focus area. I don't think 'out of focus' and 'bokeh' are
> the same thing; the latter refers to a semi-mystical aesthetic
> perceivable to some within the out of focus area. Regarding artifacts
> caused by mirror telephoto lenses... this is the one example that
> everyone points to, but even this I think misses the point of 'bokeh,'
> at least what I've been reading about it. Besides, I remember photo
> magazines of the 70s, around the time mirror cat lenses were becoming
> popular, proclaiming what a neat effect specular ringing was. SHows how
> fashions change.
I agree that some of these discussions do get rather weepy eyed but see this
webpage for a tangible example of bad bokeh: http://fox.nstn.ca/%7Ehmmerk/
I think that a paramount criterian for judging the quality of a lens is
its sharpness but in general I believe that if a lens renders background
parts of an image in a distracting way this is also quite detremental to
image quality.
Jack Walker
Date: Thu, 06 Aug 1998
From: Alan Gale asgale@mintz.com
Subject: Use of DC functionality: bokeh versus DOF
F. Javier Heredia asked:
Does really the DC function control the DOF? Recently it has been
a thread about "bokeh" in rec.photo.equipment.35mm, and the DC
Nikkors has been mentioned. I haven't any of this lenses, but
what I understood after reading the thread is that DC lenses
doesn't affect the DOF, only the "bokeh". I'm wrong?
The DC lenses let you manipulate spherical aberration. DOF is partly a
function of spherical aberration. Accordingly, manipulating spherical
aberration via DC function necessarily has an effect on DOF.
I'll try to explain. If I get some of this wrong, I'm sure I'll be corrected
by
more knowledgeable members of the Digest.
When a lens is focussed on an object, not all light bouncing off the object
and passing through the lens is focussed exactly on the film plane.
Light passing close to the optical center of the lens is sharply focussed
as a point on the film plane. Because of the spherical shape of the lens,
however, light coming in through the edges of the lens is focussed at a
slight distance from the film plane, hence "spherical aberration."
That's why stopping down a lens, i.e. using a small aperture, increases
DOF. Essentially, with a small aperture, you are using only a very small
portion of the lens close to its optical center which is relatively flat as
compared to the more spherical lens surface that gets used at max
aperture. This means the sharply focussed images from near the optical
center are not being overlapped by the more out-of-focus images coming
from the edges of the lens.
If you are near sighted, you can demonstrate the effect of spherical
aberration and stopping down with a little experiment. Take off your
glasses, close one eye, and look at a distance object. Pretty blurry,
right? Now, take a piece of paper and make a pin hole in it . With
glasses still off, put the same eye up to the pin-hole (keeping the other
eye closed as before) and you will be surprised how much better you
can resolve distant objects. The pin hole is like a very small
aperture, so
that you are only using the optical center of your cornea, which is
relatively flat compared to the edges of the cornea which are more highly
curved than a person with 20-20 vision and hence making you
near-sighted, i.e. inducing more spherical aberration than a person with
20-20 vision.
Lens manufacturers use various elements and groups of elements to
help "correct" but not totally eliminate spherical aberration. The DC ring
on DC Nikkors manipulates these elements allowing the user to select
over or under correction as compared to "normal" correction. At
relatively large apertures, f2, f2.8, f4, that manipulation has an effect on
the DOF from very slight to very pronounced depending on aperture and
how far you turn the DC ring and whether you set it to "front" or "back".
The effect is virtually imperceptible, however, at very small apertures
where spherical aberration is at its least to begin with. Hence, DC ring
can be set up with apertures up to f5.6. With apertures smaller than 5.6,
the DC effect is negligible.
Does DC affect bokeh? I think so, but bokeh seems very subjective and
ill-defined. With or without manipulating the DC ring, I find the out of
focus portions of my pictures to be pleasing with my 105 DC.
Alan
asgale@mintz.com
From Nikon Digest:
Date: Fri, 14 Aug 1998
From: Alexander Starcevic starcevic@email.ch
Subject: Fast Nikkors and "bokeh"?
I'm looking for a fast normal lens. I used to have the Nikkor AIS 50/1.4,
but sold it, because I was very disappointed with the pictures I got from
it. It is probably a very sharp and contrasty lens, but the rendering of
the blurred background (bokeh) seemed very "aggressive" und unpleasing to
me. I used the lens for low light situations und shot wide open most of the
time. So now I'm looking for an alternative to go with my FE2. It should be
a fast normal lens with smooth rendering of the blurred background. There
are couple of lenses out there: several versions of the 50/1.4, 50/1.2,
58/1.2 Noct, possibly a 55/1.2 (not sure) etc. It doesn't need to be the
sharpest and most contrasty lens, because I use it mainly for portraits in
low-light (for sharpness I have the 55/2.8 Micro). I will use the lens
mostly wide open. Also, is there a way to tell how a lens renders the
blurred background - without letting film through the camera (in case I see
something interesting in a shop...)?
Before I had the experience with this lens, I didn't really understand the
talking about bokeh. But now when I compare the bokeh of the AIS 50/1.4 to
the AIS 105/2.5's, I know what you guys are talking about! And I also know
why the 105/2.5 is so highly regarded by many!
I would be very happy to get some suggestions and responses from people
with first-hand experience.
Alexander Starcevic, Japan
From Nikon Digest:
Date: Mon, 17 Aug 1998
From: "Michael A. Covington" covington@mindspring.com
Subject: Evaluating bokeh without film
You can easily evaluate the bokeh of a lens by looking at a very distant
point source of light, such as a very small electric light or the sun
glinting off a curved surface, and putting it out of focus.
Be warned, though, that the pursuit of pleasing bokeh can easily become a
Cult of Bad Lenses. Pleasing bokeh generally comes from uncorrected
spherical aberration, which costs you sharpness.
Michael A. Covington / AI Center / The University of Georgia
http://www.ai.uga.edu/~mc http://www.mindspring.com/~covington
From: joe-b@dircon.co.uk (Joe Berenbaum)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: MF Bokeh (Was: Camera quality question new turn)
Date: Wed, 26 Aug 1998
lemon@lime.org (lemonade) wrote:
>Interestingly, in a recent review of the Contax G2 in, if I recall
>correctly, whatever the old Camera and Darkroom or Darkroom Techniques
>became, while one reviewer raved about the sharpness of the Zeiss lenses,
>another complained that Zeiss lenses in general have terrible bokeh, while
>Leica ones are great. That's in 35mm of course. One would expect the Leitz
>lenses to have great bokeh, with their umpteen-bladed diaphragms.
Just a point of information- number of diaphragm blades may have
something to do with bokeh but it isn't the primary cause, since
differences are most apparent (to me anyway) with lenses wide open,
where the diaphragm blades take no part in forming the image. Bokeh
refers to out of focus parts of the image, not just highlights from
out of focus light sources. Comparison of a 1959 Elmar with the
current Elmar-M shows no difference in bokeh. One has something like
13 blades, one has six. It's the glass (ie the optical design) that
gives the visual differences, not the diaphragm.
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: MF Bokeh (Was: Camera quality question new turn)
From: jalbert@nyx10.nyx.net (Joseph Albert)
Date: Fri, 28 Aug 1998
LDaneman ldaneman@aol.com wrote:
>I disagree. I have used both Nikon, Leica, and various Japanese and American
>lenses and the out-of-focus quality adds a painterly affect that is quite
>noticeable.
>
>If focus and sharpness is a factor of circle of confusion, the quality of the
>out-of-focus circle of confusion is a secondary but very real quality. True,
>Nikon exhibits the double-line bokeh which I never found aesthetically
>appealing. The old Leica lens and similar designs exhibit a soft, round, rich
>out-of-focus quality. Some say bokeh is just a factor of how many leaves are in
>your iris. There is more to it.
lens aberrations, especially spherical aberration, contribute to
more creamy out of focus areas. There are some people who swear
by the Tessar lens formula because its residual spherical aberration
wide open makes for very smooth out of focus effects, and the aberrations
go away as the lens is stopped down, gradually sharpening the corners as they
gradually come into the depth of field.
I've heard some folks say that Leitz deliberately designs in a measure
of spherical aberration because of this, though this might be mythology.
But older, single-coated Tessar-type lenses abound for medium-format.
With such few air-glass surfaces, the single-coated optics are capable
of very snappy, contrasty images. Koni-omega 90mm and 135mm or
Mamiya Press 90mm, 100mm (f/3.5 version), 127mm, 150mm are examples,
and many a TLR have Tessar type lenses also.
j. albert
From: drtsang@my-dejanews.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: MF Bokeh (Was: Camera quality question new turn)
Date: Fri, 28 Aug 1998
What the hell is 'bokeh'?
Well, some people have given the definition of "bokeh" which is the rendering
of out-of-focus areas of a picture. Others have claimed it to be over-rated
and basically irrelevant.
It seems that not that many people (even some professionals) really pay
much attention to it. I myself didn't know anything about it until I got
my first set of slides back, which was shot on a spanking-new Nikkor
system (primes). I looked through them, they were SHARP... but then I
noticed that the out-of-focus highlights were doubled and hard-edged. I
asked the photo guy (this was at Samy's Camera in Los Angeles) and he
said, "This is an example of bad bokeh." He then went on to explain what
it was. He then pulled out an ilfochrome which showed perfect bokeh, and
I noticed this straight away. The softer out-of-focus areas made the
in-focus areas appear much sharper and more three dimensional. Turns out
this image was shot with Leica R equipment.
From: "Michael Liczbanski" ***@email.msn.com
Subject: Re: MF Bokeh Was: Camera quality question new turn
Date: Fri, 28 Aug 1998
What the hell is 'bokeh'?
Here is a part of the message posted by someone a few months ago on the
same subject.
======================================================
As some people have already said, "boke" simply means "out of focus."
But when you talk about "dirty boke" whose representative is "ni sen boke"
or double image, you are talking about "boke aji" more precisely speaking.
"Aji" means "taste" so it is subjective obviously. When you talk about
"boke aji" (of the lens) you are talking about how beautiful or how dirty
the out of focus image looks to you.
==========================================
Forwarded by
Michael
==============================
***=mliczbanski in my email address
==============================
From Nikon Digest:
Date: Tue, 18 Aug 1998
From: ballen@ms.com (William Allen)
Subject: Evaluating bokeh without film
I'm glad to see someone point this out. Probably the most pleasing
bokeh of any of my shots was using a cheap, unknown origin, macro
filter on an AF35f4-5.6D lens. Hardly high quality stuff.
Michael A. Covington writes:
> Be warned, though, that the pursuit of pleasing bokeh can easily become a
> Cult of Bad Lenses. Pleasing bokeh generally comes from uncorrected
> spherical aberration, which costs you sharpness.
>
> Michael A. Covington / AI Center / The University of Georgia
> http://www.ai.uga.edu/~mc http://www.mindspring.com/~covington <><
From: rpn1@cornell.edu (Neuman-Ruether)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Bokeh? Bokeh? What's this bokeh?
Date: Tue, 20 Oct 1998
pchefurka@plaintree.com (Paul
Chefurka) wrote:
>Art Houston serastro@home.com
>wrote:
>>Help please. I've been a photographer for a long time but I've only
>>recently been seeing this term, bokeh, in the context of lens quality.
>>Its not in my dictionary.
>It's a term borrowed from Japanese, and popularized a year or two ago
>in a Photo Techniques article.
>
>It refers to the quality of the out-of-focus portions of an image -
>specifically the rendering of o-o-f details or contrast edges. some
>lenses have a very smooth character (Leica 35 and 50 Summicrons are
>the canonical examples of this), and some lenses exhibit a "harsher"
>appearance, to the extent of a doubling of high-contrast transitions.
>The Nikkor 50/1.8 is often cited as an example of the latter, and my
>55/2.8 Micro also shows this characteristic.
>
>There is much debate as to what influences it - some say residual abbe
>rations, some say the number of blades in the diaphragm, others say
>it's the work of the magic photo pixies. It's uncertain to what
>extent "good bokeh" (i.e. the smooth kind) can be designed into a
>lens, and to what extent it's a happy accident of the overall lens
>design.
>
>There's also a lot of debate over whether it matters. Some feel that
>if the sharp bits are sharp, then the oout-of-focus bits don't matter.
>Others feel that the quality of those o-o-f bits adds to the overall
>"feel" of the image and is thus important.
>
>I think the reason the term comes out of Japanese aesthetics is that
>they have a tradition of valuing the "negative space" in images,
>considering the background to be of equal value to the subject. the
>traditional Western aesthetic ascribes more importance to the subject.
>
>Paul Chefurka
Nice explanation...!
However, some of us consider "bokeh" important, but prefer
"bad" bokeh - as in "bad bokeh" is good bokeh, and "good
bokeh" is bad...! ;-) For examples of photos that could not
be taken (or taken as well...) with lenses with "good bokeh",
I refer you to my web page - see the cat and car photos
under "Aht Fotoz", and most of the "Sun-Plants" series,
under "Changing Showz". These depend on a hard-edged
rendering of out-of-focus material...
David Ruether
ruether@fcinet.com
rpn1@cornell.edu
http://www.fcinet.com/ruether
From: "Fred Whitlock" afc@cl-sys.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Bokeh? Bokeh? (optical tradeoffs)
Date: Wed, 21 Oct 1998
An interesting can of worms, huh? I suspect you didn't expect to get
such a
thread started. In addition to being a photographer, I'm involved in the
high end audio business. I can liken the debate over "bokeh" as similar to
almost every debate that occurs in high end audio. Audiophiles talk about
"imaging" and "pace" and a number of other subjective terms when describing
the sound of a piece of audio gear. I think wine lovers have similar
discussions. It's one of those fascinations with minutiae that drives
hobbyists in a number of disciplines.
Obviously, whether the out-of-focus highlights in a photograph are good or
bad is a subjective thing-a matter of preference. Whether a lens has good
or bad "bokeh" is a matter of preferring one trade off in lens design
against another. It is impossible to design a lens without trade offs.
Just as resolution and contrast are somewhat mutually exclusive in lens
design, so are other characteristics of optical performance.
Interestingly, the term is Japanese and the Japanese tend to design lenses
with higher contrast and worse "bokeh" (and a little less resolution) than
the Germans do. German taste in lens design usually tends toward
sacrificing contrast to get a couple of more lines of resolution.
Naturally, there are exceptions but it's a good average description of
differences in design taste. The key word here is taste. Since you can't
have lens design without tradeoffs you choose to emphasize those
characteristics that are most important to you. That varies from company to
company, designer to designer and lens to lens. It gives camera lovers like
us something to debate.
What's my take on "bokeh?" Couldn't care less. I use out-of-focus areas in
a photograph to help isolate a main subject against and uninteresting or
distracting background. It's an element of composition. When I make
photographs with shallow depth of field I'm trying to get the viewer's eye
away from the (out of focus) background and drawn to the main subject. My
hope is that the viewer will ignore the background, throw it out of focus,
just like I did. My hope is that the viewer won't notice whether the
highlights are even there let alone that they have good or bad bokeh. One
could use out of focus highlights as a compositional element but that's not
my style of photography. If it's yours then you should probably care about
bokeh.
Incidentally, since we're discussing matters of preference in lens design I
also prefer contrast over resolution in smaller film formats like 35mm
and I
prefer resolution over contrast in larger formats like 4X5. As the format
increases in size the lenses have to cover more film and design tradeoffs
cause lenses to get a little bit lower in resolution. Don't get me wrong,
the larger film format and consequent image magnification more than
compensates for the reduction in resolution. That's why large format
photographs are so much more detailed. But if you were to take a 135mm lens
designed for 4X5 cameras and expose a 35mm piece of film and then expose
another piece with a 135mm lens designed for 35mm cameras, you would be able
to squeeze more lines of resolution on the film with the latter lens. In
their respective cameras, though, the 135mm focal length would be a
slightly wide normal lens on the 4X5 and a medium long lens on a 35mm
camera.
So 35mm lenses are very sharp by virtue of their limited coverage. Video
camera lenses of comparable quality are even sharper since those lenses have
to deal with even less coverage. I like contrasty 35mm camera lenses like
those made by Nikon and Canon and I like (relatively) high resolution lenses
on 4X5 cameras like those made by Rodenstock and Schneider. Just a matter
of preference.
Every now and then a design comes together in a special way. Sometimes the
tradeoffs are minimized and relatively high resolution and relatively high
contrast come together at the same time. There are always tradeoffs. Some
very few lens designs, though, close the gap. Some examples might be the AF
180mm f2.8 Nikkor lens which displays more than the usual resolution for
lenses of its type and the Leica 35mm f2 Summicron lens which displays more
than the usual contrast for lenses of its type. The 80mm Zeiss Planar on
the Hasselblad and the 210mm f5.6 Rodenstock for view cameras are a couple
of others that come to mind in other formats. These become magical
lenses-real optical treasures because they make eye popping photographs.
None of them are among the most expensive lenses of their types. They are
all relatively simple in design and they make particularly great photographs
whether the bokeh is good or bad. Perhaps the bokeh enthusiasts would like
to debate the quality of bokeh in these high performance optics. It's all
subjectivism after all.
Well this thread sure got a few words out of me. Good shooting.
Fred
Maplewood Photography et al
http://www.maplewoodphoto.com
From: Roger Bergeron roger_b@earthlink.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Bokeh? Bokeh? What's this bokeh?
Date: Wed, 21 Oct 1998
Interesting topic. 'PHOTO Techniques' (May/June 97) did an article (13pgs)
on this very subject (3 parts: 1-What is Bokeh, 2-Notes on the Terminology
of Bokeh, 3-A Technical View of Bokeh). The idea of considering
out-of-focus characteristics of an image IMO broadens the idea of what
Image Making is all about. I have no intention of making a major in-depth
study on Bokeh, but did give the magazine one year subscription because
they publish the topic.
Hope this is of some value.
regards
roger
From: AlanBall@compuserve.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Bokeh? Bokeh? What's this bokeh?
Date: Thu, 22 Oct 1998
chefurka@magma.ca (Paul Chefurka) wrote:
>...
> Oddly enough, I've never heard it discussed as a "Japanese vs. German"
> issue - lens lines that are frequently mentioned as having very smooth
> of characteristics are Minolta and Pentax, as well as Leica. Some
> Canons have this reputation as well (I think one of their fast 35's
> comes up a fair bit). The only Japanese maker that takes a knock for
> this is Nikon, and mainly for their 50's. I use one of their 180's,
> however, that has the smooth character. So the quality of bokeh is
> not even consistent across single manufaturers' lens lines.
The new thing regarding the bokeh debate is IMHO the inclusion of the notion
into the computing of lens designs. Up to now, as you point out, it seems
that bokeh was 'accidently' smooth or hard edged on lens designs, depending
mainly on the way the residual spherical aberrations were managed. The number
of iris blades does have an influence on the rendering of o-o-f highlights,
which are (only) part of the bokeh debate.
There is even a new generation of lenses that allow the user to tweak
bokeh: both Nikkor DC lenses and the very latest Minolta 135mm f2.8 allow
that. If one reads the more recent data sheets of the manufacturers, one
will notice that most of the time now there is a line refering to the
number of blades in the iris and to the shape of those blades. This shows
that bokeh is today being taken into account at the design stage of lenses
(and in their marketing as well, of course).
Now, what really lacks, is benchmarking references as to how to define
bokeh characteristics. Without benchmarks, it is true that the
qualification of 'good' bokeh is something purely subjective and
arbitrary. It is also true that bokeh is complicated to observe, with
radical differences in background and foreground renderings for each lens
design . The bokeh behaviour of a particular lens also changes with
aperture settings and with the relative distances between camera, subject
and out of focus elements. This is much more complicated to measure than
other optical characteristics which are derived from observing 2D chart
images.
All this certainly shows that the debate on bokeh is not only in the hands
of Leica freaks with too much time and money on their hands. As a Leica
user, I shall state this: the 90mm f2.8 Summicron-M gives one of the best
bokeh I've ever seen. For me "best" is smooth, 'round', mushed
backgrounds. The other best, for me, is the Tamron 90mm f2.5 SP2, which is
a quite unexpensive purely Japanese design. And there are plenty of other
great performers in all lines, with NO 'national' preference. There is
such a thing as 'lens nationalism' which i find crazy. It gets to the
point were some maniacs define good Japanese lenses as having a
"faux-German quality" (sic)... But this is somewhat off-topic.
Friendly regards
Alan.
From: drmoijk@online.no (Geir Eivind Mork)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Bokeh? Bokeh? What's this bokeh?
Date: Thu, 22 Oct 1998
http://fox.nstn.ca/~hmmerk/ATVB.pdf
I belive it's this.. If I didn't pick the wrong link.. Explained me at
last what good/bad bokeh is.
rec.photo.equipment.35mm
From: kt0911@aol.com (KT0911)
[1] Re: Bokeh - etymology?
Date: Fri Dec 04 1998
Bokeh is so spelled that it would not be mispronunciated as boke (bowk).
Bokeh (pronounced bo-keh) literally means blur. It is also used to
describe the state of blurred mind, such as jet lag or those caused by
aging. Either way, it indicates fuzzy, out-of-focus situation.
This is obviously one of those words which became an accepted technical
term which is frequently used in a specific industry the word is mostly
used in. I orginally came from Japan but did not know until recently that
the word bokeh has been used to describe blur in photography.
Interpreting from the way it is used, it is used fairly specifically those
background blurs thrown in a close-up situation with shallow DOF, even
thopugh bokeh in general Japanese language simply means a blurry state.
Hope I am not misleading anybody.
rec.photo.equipment.medium-format
From: lemon@lime.org (lemonade)
[1] Example of really bad bokeh
Date: Wed Jan 20 1999
Background: "bokeh" refers to the characteristics of the out-of-focus areas
of the image. These are not tested for in standard tests of resolution and
contrast, modulation transfer functions, etc. There are as yet no standard
methods for measuring bokeh.
Some while ago I asked in this NG if anybody could compare the bokeh of the
various major MF lens systems. As I recall I received essentially no reply,
apart from a couple of people saying everything to do with bokeh was a
bunch of hokum, or should I say bokum.
Well, here is an example of terrible bokeh that should be both readily
available and instructive, in the well-known Sierra Club Wilderness
Engagement Calendar, 1999. Most of you probably are familiar with this
calendar series, since it is one of the pre-eminent forums for the best in
wilderness photography. Virtually all of the photos are medium or large
format- it's easy to tell the difference between these and the occasional
35mm photographs- and the colour reproduction is of the highest quality.
There is a comparable calendar published by the Audubon Nature Society; it
differs mainly in that the photographic details- camera, lens, film,
exposure data- are included in the caption, and in certain tendencies in
the subject matter. It would be a better one to look at, but I wasn't able
to examine one in detail.
The example of really bad bokeh is the second photograph in the calendar,
entitled "Sandhill cranes, Bosque Del Apache National Wildlife Refuge, New
Mexico"; photographer Scott Pope. It seems to be made with a moderate to
high-powered telephoto. It is evidently a 35mm photo.
On the horizon is a mountain range, and before it, a band of darker forest.
If you look at the horizontal boundary lines, you'll see there is a very
pronounced "double line" effect. If you look at the blurred trees, there
aren't clear enough lines to notice this, but it gives the trees a kind of
unpleasant blurred effect. The foreground blur, what can be seen, doesn't
seem to show this as much, but there are no such clear examples to be sure.
The cranes themselves are very sharp.
In the 35mm NG, there has been some mention of the "famous Nikkor double
line bokeh", so it's a reasonable guess that the photo was taken with a
Nikon, but there is no info in the caption to be sure.
This led me to look through some of my old photos and brochures to see what
I could see. What I found was that in very few of my camera brochures, were
there any photos where bokeh could be judged. For example, in a lavishly
illustrated, 50-odd page brochure on Nikkor lenses, there was not one
single photo that could be used to judge bokeh: they were essentially all
sharp from corner to corner. Photos I looked at taken with a Zeiss 150 on a
Hasselblad had really nice bokeh, as well as several Pentax lenses, with
very soft, circular diaphragm images, no harshness at all; and both
Hasselblad and Pentax brochures showed a few photographs with nice bokeh.
Bokeh in photos from a Bronica brochure was fine. In a Mamiya 645 brochure,
there was a bit of double-line and hard edges to some background blur, but
nowhere near as bad as the photo in the Sierra Club calendar. By the way
hardly any of the other photos in the calendar showed any out of focus
areas at all. This is just a superficial perusal; I still haven't looked at
most of my own photos, let alone most of my brochures.
In a recent, was it Phototechniques?, there was a review of the Contax G2
system, and it talked about the very harsh Zeiss bokeh. Looking at the
photos published with the story, I would have to agree; but looking at the
photos I have from Zeiss lenses on a Hasselblad, I would say no. The
article also talked about the excellent Leica bokeh. Looking at several
photos on the Leica on-line photo gallery
http://www.leica-camera.com/galery/rosing/rosing_e.htm
, there
are several
pictures with out of focus backgrounds that look quite nice, within the
limitations of resolution on the web.
Conclusion: differences in bokeh are real, make a big impact on the image,
and are well hidden in standard reviews, lens testing, and product
literature, which concentrate almost exclusively on the in focus areas.
One more remark: many of the pictures in the Sierra Club calendar appear to
have been taken using an enhancing filter. They look unnatural, and I am
opposed to this in a calendar of this type. Photography is, depending on
the context, either documentary or artistic expression or a little bit of
both, and in a wilderness calendar of this sort, there is a tacit
expectation of reasonably accurate realism. If this is to be violated, a
notation to that effect should be added, just as if it were digitally
enhanced.
--
Due to the intolerable volume of spam these days, I no longer supply a
valid email address.
rec.photo.equipment.medium-format
From: lemon@lime.org (lemonade)
[1] Great Bokeh resources in PDF format
Date: Fri Feb 12 1999
I've posted a couple of times here asking about the bokeh of various lenses
and so on. Well, I've just come across a great resource in PDF format, as
well as some related articles on depth of field:
Check out
http://fox.nstn.ca/%7Ehmmerk/
and specifically, for the PDF downloads,
http://fox.nstn.ca/%7Ehmmerk/HMArtls.html#anchor26001
By the way I got these by following links from Robert Monaghan's pages
http://medfmt.8k.com/mf/
(By the way Bob, a link you mentioned earlier,
medfmt.8k.com/mf/film.html
doesn't seem to be working.)
I've been exploring these pages more lately and I have to say that
photographers everywhere owe Bob a tremendous debt. His pages are a truly
stunning resource of vast coverage and detail.
--
rec.photo.equipment.35mm
[3] Re: cons of fast lenses?
From: "Jim Williams" jlw@nospam.net
Date: Thu Apr 01 1999
>I have been recently (past month or two?) been toying w/ getting a fast
>normal lens and using it as a "short telephoto" because I love the smoothness
>of the blurry backgrounds and the 50mm focal length w/c helps me shoot
>physically closer than a fast 100 or longer lens would allow.
>
>My question to you is, given I am talking about fast 50mm lenses here for
>35mm, would I see a great difference in the smoothness/softness/out of focus
>quality between an f/1.4, an f/1.2, and an f/1.0? Would there be a remarkable
>difference in background softness or something that is barely detectable?
Pardon me for butting in, but based on use of a lot of wide-aperture
lenses, my thoughts are:
-- You won't see a lot of difference in the AMOUNT of background
"unsharpness" between f/1.4 and f/1.2 lenses at full aperture, or between
f/1.2 and f/1.0; you might see a visible difference between f/1.4 and
f/1.4, but it'll be slight. There are mathematical formulae you can use to
calculate the "blur disk" of an out-of-focus image to get an idea of just
HOW out of focus it would be with each aperture at various distances.
BUT...
-- The *character* of the out-of-focus image is the thing that really makes
the difference in producing that smooth appearance you like, and this is
determined by the optical design of the individual lens as well as by its
aperture. (At the risk of reviving a well-worn topic on this newsgroup,
Japanese photographers use the word "bokeh" to describe this subjective
character of out-of-focus areas.) Interestingly, some of the more expensive
superspeed lenses (such as, so I've been told, the 50mm f/1.2 Noct-Nikkor,
with its aspherical surface) produce less desirable bokeh than their less
expensive relatives (e.g. the f/1.2 non-Noct Nikkor) because the more
expensive lenses have been specially corrected to reduce the aberrations
that produce the pleasing bokeh effect!
In other words, you'll have to try individual lenses to see what ones
produce the appearance you want, keeping your other needs in mind. For
example, one very knowledgeable photographer has told me the prettiest
bokeh he's ever seen came from the old 58mm f/1.2 Minolta Rokkor lens...
although that doesn't do you much good if you don't use Minolta!
Date: Sat, 08 May 1999
From: John J Stafford Stafford@WIND.WINONA.MSUS.EDU
Subject: Re: [KOML] 180mm Bokeh
GRAPHIC@delphi.com wrote:
> Isn't Bokeh to a large degree governed by the number of diaphram blades in
the iris?
The shape of the diaphram is only one contributing factor. Certainly, if
it is far from round (square, triangular, octagon, etc) you might
actually see the shape of the diaphram in highlights, however other
significant contributors are the degree of correction for various
aberations. For example, undercorrection for spherical aberation can
create round images with dark centres and overcorrection can create
round images with bright rims. Another factor is fundamental lens design
which can produce double-images in Bokeh (the Japanese students here
call it Cross-Eyed or ni-san bokeh (I think that's the spelling!))
From Nikon Mailing List:
Date: Tue, 25 May 1999
From: "Roland Vink" roland.vink@ait.ac.nz
Subject: [NIKON] Re: Nikkor bokeh
> Unfortunately in my experience the best way to achieve good bokeh is to
> use a bad lens. Among my shots, be best bokeh that I've gotten as using a
> cheap second-hand 10x close range filter mounted on a Nikkor AF35-80/4-5.6
> plastic mount lens (not that bad a lens optically). The flower (the
> subject) was soft as you might expect, but the bokeh is beautiful.
This is not a silly as it seems. Lenses undercorrected for spherical
abberations generally have smooth background bokeh. Most closeup
filters are simple spherical lenses, which are totally uncorrected. If your
closeup lens has bad bokeh, a way to improve it is to put a diopter in front
of it.
From Nikon Mailing List:
Date: Sat, 1 May 1999
From: Larry Kopitnik kopitnil@marketingcomm.com
Subject: [NIKON] re: 85mm AF-D, f1.8 vs. f1.4 and Bokeh
>Bokeh is the real issue between the two, and the f1.4 has much smoother,
>rounder bokeh. Highlights beyond the DOF are often quite hexagonal with
>the slower lens. All it would take is two more aperture blades--cheap!--to
>give the f1.8 comparable bokeh qualities, but Nikon seems intent on
>blackmailing you into buying pro glass.
"Bokeh" involves more than just the number of aperture blades. It's an
integral part of the lens design, relating to the designer's corrections
(specifically, overcorrection or undercorrection) of spherical aberrations.
While number of aperture blades is one element that can have an impact,
both the 75-150 Series E Nikkor and 60 mm f/2.8 Micro-Nikkor display
wonderful "bokeh" despite having just 7 aperture blades.
The matter of "bokeh" was brought to light through a series of articles in
the May/June, 1997 issue of the American magazine "Photo Techniques."
Copies can still be purchased through the "Photo Techniques" web site at
http://www.phototechmag.com/
Larry
From Nikon Mailing List:
Date: Sun, 02 May 1999
From: Adriel adey@HK.Super.NET
Subject: [NIKON] Bokeh and my new 80-200D!
In case any of you were wondering, the literal translation for "bokeh"
(Japanese)
to English is "blur" su I guess it goes without saying.... :)
On a more "nikony" note, I just, after MUCH deliberation bought my non-AF-S
ED Zoom Nikkor 80-200 f/2.8D (yeah, the one with the permanent tripod collar)
and absolutely LOVE IT!!!
Thanks again to everyone who helped me make this decision! Though not the
AF-S, the AF on this lens is pretty darn fast!
Regards,
AD
Larry Kopitnik wrote:
> >Bokeh is the real issue between the two, and the f1.4 has much smoother,
> >rounder bokeh. Highlights beyond the DOF are often quite hexagonal with
> >the slower lens. All it would take is two more aperture blades--cheap!--to
> >give the f1.8 comparable bokeh qualities, but Nikon seems intent on
> >blackmailing you into buying pro glass.
>
> "Bokeh" involves more than just the number of aperture blades. It's an
> integral part of the lens design, relating to the designer's corrections
> (specifically, overcorrection or undercorrection) of spherical aberrations.
> While number of aperture blades is one element that can have an impact,
> both the 75-150 Series E Nikkor and 60 mm f/2.8 Micro-Nikkor display
> wonderful "bokeh" despite having just 7 aperture blades.
>
> The matter of "bokeh" was brought to light through a series of articles in
> the May/June, 1997 issue of the American magazine "Photo Techniques."
> Copies can still be purchased through the "Photo Techniques" web site at
> http://www.phototechmag.com/
From Nikon Mailing List:
Date: Mon, 3 May 1999
From: "Roland Vink" roland.vink@ait.ac.nz
Subject: [NIKON] Re: 85mm AF-D, f1.8 vs. f1.4
> >Bokeh is the real issue between the two, and the f1.4 has much smoother,
> >rounder bokeh. Highlights beyond the DOF are often quite hexagonal with
> >the slower lens. All it would take is two more aperture blades--cheap!--to
> >give the f1.8 comparable bokeh qualities, but Nikon seems intent on
> >blackmailing you into buying pro glass.
>
> According to the Nikon Lens Specs FAQ, both the AF-D 85mm/1.8 and 1.4
> IF have 9 blades diaphragm but the Nikon site says the 1.4 has extra
> blades (not necessarily just 2 more) to ensure better bokeh. Maybe the
> extra blades overlaps the first set to make them rounder.
I believe that 9 diaphram blades IS extra, since most Nikon lenses have only
7 blades. The difference is that the blades of the 85/1.4 are more curved,
and fit together to form a more rounded aperture, while the 85/1.8 forms
a 9-
sided polygon.
The 105/2 and 135/2 DC lenses, and the new AF-S lenses also have the new
rounded aperture.
As far as I know, no Nikkor has more blades, some of the pre-AI lenses had
less, with 6 or even 5 blades.
Note that the shape of the aperture (polygonal or rounded) only affects the
shape of defocused highlights, which has only a small affect on bokeh.
Bokeh is determined more by how smoothly those highlights blend
together, and that is mostly due to how a lens is corrected for spherical
abberations.
Roland.
From Nikon Mailing List:
Date: Sun, 16 May 1999
From: Bryce Robert Hashizume brhashiz@ucalgary.ca
Subject: [NIKON] Re: DC lenses
Adriel is way off in his explanation of how DC lenses work and what they
do.
DC lenses do not allow you to get the dof of f/16 with an aperture of
f/2.8, or anything like that. What DC lenses do is allow the user to
control the smoothness of the out of focus portions of a picture (i.e., it
controls bokeh). If you set the DC ring to a number numerically smaller
than the aperture (e.g., aperture at f/4, DC at Rear 2), the background
blur will be more smooth, and the foreground blurb more distracting. The
forward/Rear difference on the ring determines whether the foreground or
background will be smooth, and the ammout of difference between the
numbers on the DC and aperture rings determines the amount of smoothening.
If the DC number is numerically higher than the aperture, a soft focus
effect is obtained. The effect of the DC is rather subtle.
How does it work? DC control works by varying the ammount of sperical
abberation. Good bokeh results from undercorrected spherical abberation.
Poor bokeh results from overcorrected sperical abberation. DC lenses
allow you to change how well spherical abberation is corrected. If you
undercorrect the background, the foreground is overcorrected. If you
undercorrect the foreground, the background is undercorrected. If you
undercorrect or overcorrect too much, you get a soft image. Because
moving the DC ring moves elements around, you have to focus after setting
the DC ring. The effect of DC is not visible in the viewfinder, and can
only be seen in the print/slide.
rec.photo.equipment.35mm
From: spoorl@aol.com (SpooRL)
[1] Re: What is 'bokeh'??
Date: Sat Aug 21 23 1999
I am partial to some of the effects described here under "bokeh." I find,
for example. that older Nikkor 105mm and 135mm lenses, used with
extension, produce a unique texture in images, particularly in the out-of
focus areas, which can occupy the majority of the frame with macro work.
That is why the "Why not just get a true Nikon Macro lens?" responses to
inquiries about using tubes and bellows are narrow and ignornant-sounding
to me.
Spoo
rec.photo.equipment.35mm
From: ckross@enteract.com (Chuck Ross)
[1] Re: What is 'bokeh'??
Date: Thu Aug 19 1999
Also see
http://www.slonet.org/~dkrehbie/bokeh/bokeh.htm
http://active.uvic.ca/~vhchan/bokeh.html
http://zuiko.sls.bc.ca/swright/archives/1997/msg02265.html
http://medfmt.8k.com/mf/bokeh.html
http://www.princeton.edu/~law/lenses.html
[gone as of 9/2002]
http://photo.net/bboard/q-and-a-fetch-msg.tcl?msg_id=0004Zn
And finally, for a really excellent PDF (Acrobat) 5-page dissertation
on bokeh, go to
http://fox.nstn.ca/~hmmerk/ATVB.pdf
....
From: LL lewislang@my-deja.com
Newsgroups: rec.photo.equipment.35mm
Subject: LENS QUALITY FAVES
Date: Sat, 07 Aug 1999
I have shot with many different brands of 35mm systems and have appreciated
the "lens signatures" (their peculiar/distinct rendition of color, tonality,
contrast, edge sharpness, bokeh/etc.) of each systemYs lenses.
This is not an attempt to start a "bokeh" or a brands war so anybody who does
not "believe" in bokeh (the qualities of the out of focus areas of a
photographic image) I will not try to convert or "enlighten" (pardon the
deliberate pun) you. I merely wish to get people's responses on which
particular lenses they are fond of for the bokeh effects and other qualities
of image rendition and why they feel that way. If you feel inspired to share
your thoughts/feelings about certain lenses please mention your brand(s),
maximum aperture of lens, bokeh/sharpness/contrast/color/other qualities of
your lens(es) and what makes them unique/why you prefer their "look"/image
rendition. I would like to keep the discussion limited to 35mm format camera
lenses, however if you feel inspired to write comments about lenses in other
formats feel free to start your own thread(s).
IYll start off with some of my faves (mostly in the wide angle to normal
range since I am a wide angle man). Bon apetit!...
Wide angles/ wide angle zooms
24-50mm
Minolta Maxxum 24-50mm f/4: Even at f/4 the blur discs have the quality
(largeness and smoothness) of a lens with a much wider maximum aperture
(f/1.4-f/1.7 range) so I find that the only time I wish I had a brighter lens
with a faster maximum aperture is not for background effects but only for a
slightly brighter viewfinder image or a faster shutter speed. Amazingly sharp
when stopped down to f/8 or f/11. This lens focuses down to about 1.1 feet
which makes it even more eseful than a lot of standard prime 50mm lenses (low
light ability excepted). I use it for photojournalism/portraiture mostly and
my only complaint is that I donYt own two of them. Color rendition is
extremely pleasing. I find the bokeh to be about equally smooth as my Canon
EF USM 100-300 (when I owned/used that lens) but I find the color rendition
of scenes (as well as the contrast far more emotionally satisfying. I had a
Nikon 25-50mm zoom (which was extremely sharp even at about 16x20") when I
was in the Nikon system but the sharpness of this lens is exceptional and
seems about equal to it but the color rendition and bokeh seem even more
pleasing.
28mm
Leica M 28mm f/2.8 Elmarit (old type, probably mid to late 1980Ys (rough
guess) vintage/non-aspheric): Sorry I cant comment about the bokeh since I
donYt remember using it wide open (this was before my "bokeh epiphany" when
the only good lens was a stopped down lens) however I just wanted to comment
on the sharpness/tonality of this lens which when used with Ektar 25 (yes,
IYm showing my age) gave 8x10Ys (prints) that seemed to be made from a high
quality 21/4 or larger format in their shapness and tonal range
Carl Zeiss 28mm Distagon f/2.8 MM (for SLR): This lens is my "surreal" lens,
not because of any kind of excessive linear distortion but because this lens
(to my eye) has one of the highest contrast levels and definitely the highest
edge sharpness of any lens IYve used. Edges of subjects seem to pop as if
they were card board cutouts placed in a scene. Wide open (and especially
when focused close/a foot and a half or so or less) the bokeh is creamy
smooth and people shots look closer to a normal or telephoto lens in their
background blur effect. Beautiful blur discs in the high lights in the
background. Combine the ultra high contrast, ultra edge sharpness and color
rendition of this lens with a Velvia (or even a Kodachrome 25 or Ektar 25
(when it still existed as afilm)) and you get images that look like they have
punchy colors/sharpness of almost another world/planet. This lens makes even
Ektachrome 400 look ultra sharp (flash doesnYt hurt either). My "wham pow
bang" lens (a lens with extra punch for photojournalistic portraits,
landscapes, etc.).
Canon 28-70mm f/2.8 L USM for Canon EOS: Shar, sharp, sharp! when stopped
down, wide open at 70mm you could almost use it as a portrait lens (although
I find 70mm a little on the short side for telephoto portrait work). Smooth
background bokeh in tight head shots. This lens seems to have nearly the same
contrast level and clarity as my Zeiss 28mm with out the in your face
sizzling edge-sharpness of that Zeiss lens for a rendition that is both ultra
sharp yet natural looking when stopped down.
35mm
Leica M 35mm f/1.4 Summilux (old type, probably early to mid 1980Ys
vintage/non-aspheric): Towards wide open (around or below f/4) this lens is
mushy (lowish contrast/resolution) but stopped down to about f/5.6 or
more it
is so unbelievably sharp that even 16x24" enlargements will cut your eyeballs
like a razor and IYve even made a 30x40" enlargement that Roger Hicks
(Shutterbug) was impressed with. This camera lens will crap out your enlarger
lens and the grain/resolution of the film you use long before it ever craps
out quality wise. Simply luscious.
Leica 35mm f/2 Summicron (old type, probably early to mid 1980Ys
vintage/non-aspheric): The lens for all other lensYs bokeh and sharpness to
be judged against. The lens quality of my 35mm R Elmarit f/2.8 lens was
spectacular, this was even better. At or near wide open buildings in the
background of NYC street portraits look like they were rendered with an air
brush -creamy smooth. The sharpness is biting but has an openess and realness
toi it (as opposed to the "surrealness" of my Zeiss lenses) that makes me
feel as if all other lenses were shot through a clear, but still evident pane
of window glass, the sharpness rendition/3-d tonality of this lens in the
sharp areas makes my eyes feel as if someone just lifted the window open and
that there is now nothing standing between me and the original scene. While
you could call my Zeiss lenses "surreal" in rendition/sharpness this lens is
probably best described as "hyperreal" (real only more so due to its openess,
long tonal range/transition, and high contrast). When I stare at images taken
by this lens my eyes could stare and stare at both in and out of focus areas
for minutes and not get tired. Even though I love the sharpness of some Nikon
lenses, and both Nikon and Leica have some excellently sharp lenses
(especially when stopped down) I like the "openess" of the contrast of the
Leica (and particularly the M) lenses as opposed to the high contrast less
3-d feel I get from the Nikons (both are different looks that might suit
different types of images equally well, but overall I prefer the Leica in
terms of colr, contrast, bokeh, etc. That is not to say I feel that way about
every Leica/Nikon lens. Stopped down I prefer the excellent sharpness of the
Nikon 24mm f/2.8 D lens to its Leica counterpart but I canYt comment on the
bokeh of the Nikon since I havenYt used it wide open, only stopped down to
about f/11 with flash on T-max 100 (which also helps with the impression of
sharpness/contrast). In defense of the Leica 24mm R lens, IYve only seen
results from a friends lens w/c might have been affected by a botched repair
job. I have no experience with the new 24mm M lens.
50mm
Zeiss 50mm f/1.4 Planar: Spanking! This lens is superbly sharp with excellent
contrast and color rendition wide open, stopped down and with any thing in
front of it with the exception of a lens cap :-). This lensYs contrast
sizzles (especially with slow speed film) but it lacks the almost overblown
edge sharpness/color intensity/contrast "surrealness" of the color
rendition/edge sharpness of the Zeiss 28mm despite its ultra high contrast.
IYve never compared it against a 50mm Leica Summicron M lens, but this is one
of the few lenses that when I used it it didnYt make me wish I
owned/used/tokk along a 50mm Leica lens too.
Pentax 50mm f/1.7 A lens: Wide open a bit mushy (soft) but with such
beautiful soft "creamy" transitions between out of focus background areas
that youYd almost swear you were using a longer focal length. Slightly
stopped down (sorry, IYm not sure at which aperture) results are razor sharp
but natural (none of the ultra contrast of my Zeiss lenses but still
extremely sharp).
Nikon 50mm f/2 AI Nikkor: Extremely usable wide open and shockingly sharp
stopped down. The blur discs are somewhat hard edged in the out of focus
background areas but even though that may be considered "bad bokeh" I donYt
find it distracting and still prefer both the color and contrast
rendition of
this lens. I much prefer this lens to the Nikon 50mm f/1.4 AIS? lens I had
but not so much for the bad bokeh that the 1.4 supposedly has but because of
the tack sharpness wide open. Yet still, I wish IYd owned/saved up for a 50mm
f/1.2 Nikon lens when I still had this system as IYve seen some exceptional
childrenYs fashion photography by Carrie Branovan (in PhotographerYs Forum?)
and I loved what the maximum ultra fast aperture of the f/1.2 lens did to
blur out the backgrounds with shallow depth of field. Unfortunately I
have no
intention of investing in another system, Nikon or otherwise, just
because I
like the effect of one lens/aperture combination. IYm getting out of Canon
EOS, but even if I were staying with my EOS thereYd be no way IYd pay several
thou for a 50mm f/1 lens (aoutofocus or not). Olympus and Pentax also
make a
50mm f/1.2 lens (Contax even made a special edition 55mm f/1.2 and I believe
there was a t one time also a Yashica 55mm f/1.2 but money and or rarity
prevent me from getting these for my current Contax system. Minolta (my
current AF system) has only a "pedestrian" f/1.4 and I have no intention of
getting a manual 50 or 58mm f/1.2 Minolta or Canon manual focus lens as I
really donYt want to start on a possible third (or fourth until I get rid of
my Canon stuff) system. (Please no e-mails about the Canon system, as IYm not
yet selling it).
Nikon Series E 50mm f/1.8: Same comments as above, extremely sharp wide open,
pleasing bokeh(smooth enough bokeh, I canYt say if its as pleasing as the f/2
since I never did a side to side), high contrast and great color rendition.
This lens and the previous lens make me still wish I had my Nikon F3
High-eyepoint.
Hope youYve enjoyed my input, now its your turn(s)...
Regards,
Lewis Lang
From Nikon Digest:
Date: Sat, 04 Sep 1999
From: Sergei sergios@altfactor.gr
Subject: Re: [NIKON] Bokeh (was Re: 85mm lenses)
>Could somebody please show me 2 identical pictures, one with good bokeh and
>one with bad bokeh, so I can finally know what is generally considered good
>vs. bad?
you quoted my mail, so.
for me, this is acceptable:
http://www.altfactor.gr/private/sergios/good.jpg
and this is bad:
http://www.altfactor.gr/private/sergios/bad.jpg
good.jpg is from Sigma 28-70 2.8 EX (probably at 70mm, wide open)
bad.jpg is Nikkor 50 1.4D, wide open (which was a bad choice of course). it
is a very specific point of the frame showing the doubling of lines. the
sigma does not do this (not that its bokeh is Great, just passable).
this is the only picture this happened and it is obvious why.
But I would never give my nikkor for the sigma.
But I would never give my nikkor for the sigma.
Sergios.
From: "kopitnil@my-deja.com" kopitnil@my-deja.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: What is 'bokeh'??
Date: Sat, 21 Aug 1999
Lewis,
First, if you like the background blur that a lens gives, then it very
much is good "bokeh" for your purposes. As the controversy this subject
stirs (in other posts, not yours) illustrates, appreciation of "bokeh"
or consideration of whether it is even important is as personal a matter
with each photographer as is appreciation of any artistic effect.
Specifically in regards to the 50 mm f/1.2 Nikkor, you describe one of
the classic ways defocused images are projected by a lens when you write
"the out of focus highlights behind the girl and the fountain in the
upper left corner of page 48 look more like "coins/discs" with edges
that are slightly brighter than their darker centers....."
An out-of-focus point of light is projected by a lens onto film
primarily in one of three ways:
1. A disk of uniform density. This usually happens only when a lens is
stopped down (so, to address Joe's post, yes, the "bokeh" of a lens can
change as the aperture setting changes).
2. A disk with a bright center and dark ring, or edge. This results in
better definition to out-of-focus subjects, and happens when spherical
aberrations are less controlled by the lens designer. This look is more
typical in Leica, Zeiss and Minolta lenses.
3. A disk with a bright ring and dark center (which is what you
describe seeing). This generally results in poorer definition to
out-of-focus subjects and doubling of out-of-focus shapes. And this
happens when spherical aberrations are more tightly controlled by the
lens designer. This look is more common among Nikon lenses.
(Although, let me be clear in citing manufacturers, that there are
exception to these generalities in all lens lines. Except maybe Zeiss --
while I'm not familiar with all Zeiss lenses, I've yet to see one with
bright ring design.)
Personally, I shoot with Nikons. But I dislike the 50 mm Nikkors because
of their strong use of bright ring "bokeh." It's not an inherintly bad
look. It does not in and of itself make a photo bad. It's just a look I
dislike. That's my personal artistic preference, nothing more (for a
normal lens I use the 35 mm f/1.4 Nikkor -- not the classicly great
"bokeh," but far prefereable to my eye to any of the 50 mm Nikkors).
Larry
Larry:
You gave us an excellent, clear, concise explanation of of "bokeh."
However, I am curious as to why you refer to the Nikon 50mm f/1.2 lens as
having "displeasing 'bokeh'." I own a copy of Photographer's Forum
magazine (February 1999) and bought it specifically for the article on
Carrie Branovan, a childrens fashion photographer who, and I'll quote from
the article "shoots almost exclusively wide open, using Nikon's fastest
lens. On my 50mm lens shooting at f/1.2, I'm able to shoot in almost no
light. I strive for very shallow depth of field which has a magical
quality"." I was especially pleased with the bokeh of the shots on pages
48, 50 and 51. Perjaps the shallow depth of field on these shots is so
alluring to me in effect that my eye doesn't concentrate on the
displeasing bokeh? Or perhaps this lens's bokeh is not so displeasing to
me anyway. Given, the out of focus highlights behind the girl and the
fountain in the upper left corner of page 48 look more like "coins/discs"
with edges that are slightly brighter than their darker centers, however,
there is not so mush of a contrast between the inner and outer parts of
the circles of confusion that my eye is drawn there and away from the
subject and shallow depth of field effect. Why do you feel the 50mm
f/1.2's bokeh is "displeasing" - I'd really like to know. Its her
shots/use of this lens that has made me want to save up for a 50mm f/1.2
Nikon (and I consider myself a wide angle man!). Also, I've heard that
Nikon's 58mm Noctilux has less pleasing bokeh than even the 50mm f/1.2
"regular" Nikkor due to the Noctilux's better correction of aberrations.
Is this true? Have you shot with either one of these Nikkors? Whart are
your conclusions about their bokehs?
Regards,
Lewis (curious about bokeh) Lang
[Ed. note: bokeh is not a new term or concept, unless you rate the 40
year old Nikon F "new" ;-)]
From: ken@ukkii.tky2.3web.ne.jp (-Ken-)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: What is 'bokeh'??
Date: 22 Aug 1999
CR> (McEowen) wrote:
...
CR> There's a lot written about the bokeh of various lenses, and much of it
CR> is on the web. My first experience with really great bokeh was around
CR> 1970, when I got a Nikon 105mm/f2.5 lens, a lens with some of the most
CR> beautiful bokeh ever encountered. Only at the time, I had no idea what
CR> "bokeh" was, or whether there even was such a word, but there was no
CR> denying the quality of images.
The word 'bokeh' has been around for a while and used not only
amongst pros or manufacturers. How long, I am not sure. I was
reminded of this a while back when I was reading a reprint of a
review of Nikon F + Nikkor S 50 F2 in Asahi Camera.
To quote, "Nikkor S 50 F2 (subtitle: bokeh is worrisome)
... Since the aberration of the lens is not that small, the
bokeh of the background when used wide open is distasteful and
tends to deform the objects themselves. ..." (AC. Sept. 1959).
The actual word they use is 'bokeh aji' (taste of bokeh, in
literal translation) --- a phrase which is still commonly used.
They use the word non-commitantly with no explanation which
shows that the word has been around longer than that. I guess I
should do a literature search at the library one of these days,
when I have the time. The idea must have been around even
longer.
Personally, I know about bokeh but there are other things that
worry me a lot more about my pics. If I become a lot better
photog, maybe I can worry about bokeh more.
---
Ken Aoki mailto:kxa@tky2.3web.ne.jp
From: Richard Cochran rcochran@netcom16.netcom.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Bokeh? What is it ??
Date: 13 Jan 2000
Two pictures are worth a thousand words:
http://www.princeton.edu/~law/bokeh/
[gone as of 9/2002]
Bokeh has a lot to do with the amount of spherical aberration in a
lens. It's not ordinarily something which you can control (except the
Nikkor DC lenses), rather, it's a characteristic of the lens design.
Aperture shape (number of blades, f-stop selected) has something to do
with it, but it's far from the determining factor.
Lots more text discussion at:
http://www.princeton.edu/~law/lenses.html
[gone as of 9/2002]
--Rich
From: joe-b@glopdircon.co.uk (Joe B.)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Are Leica lenses really better?
Date: Fri, 14 Jan 2000
....
>Actually I would have to agree about the BOKEH effect.
>Colours and contrast and sharpness are great, but the out of focus area has
>a quality about it rarely found in other lenses.
>I am led to believe it is related to the shaping of the aperture and the
>number of blades used to make the aperture almost creating a perfect circle.
>
>
>Kosh
But have you ever wondered why you get the same kind of bokeh when the
diaphragn is wide open, ie not in the light path at all? Hint; its the
glass, not the diaphragm. If you compare the out of focus background
with wide open shots taken with a 50mm Leica Summilux and a 50mm 1.4
Nikkor, there is a big difference, but no aperture blades are
influencing the appearance of the puicture. I think the diaphragm is
harped apon by some manufacturers because they think people will grasp
that idea easier than the idea that it is the oprtical design. You can
advertise "new circular aperture" (a tangible physical thing) easier
than you can advertise "nice soft bokeh for out of focus areas". It is
easier to grasp, even if it doesn't actually infuence what people seem
to think it does. A circular (or other shaped) diaphragm will just
affect the shape of out of focus highlights when the lens is not wide
open.
Joe B.
From: spam-abuse@worldnet.att.net (Tom)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Are Leica lenses really better?
Date: Fri, 14 Jan 2000
ark@research.att.com (Andrew Koenig)
wrote:
>Joe B. joe-b@glopdircon.co.uk wrote:
>
>>But have you ever wondered why you get the same kind of bokeh when the
>>diaphragn is wide open, ie not in the light path at all? Hint; its the
>>glass, not the diaphragm.
>
>I doubt it.
>
>Ever look through a wide-open lens off axis? Inevitably, the
>of the opening you see is not round, because various parts of the
>lens structure get in the way.
>
>An out-of-focus image of a point takes the shape of the lens
>as seen from that part of the film, which means that the physical
>shape inevitably has a substantial effect on the appearance
>of out-of-focus images.
>--
>Andrew Koenig, ark@research.att.com, http://www.research.att.com/info/ark
============================================
Actually, you are both partially correct.
Obviously, for each ray entering the lens, there is always a limiting
aperature somewhere in the lens, and these obstructions always
contribute to the overall shape of the blur pattern. Sometimes the
adjustable aperture catches most of the edge rays, sometimes its other
internal components like mounting hardware, flair reducing baffles,
etc.
However, even exactly on the centerline of the lens, out of focus
point sources can still appear as undesirable (but symmetrical)
doughnuts, with the darker center due primarily to the optical design
and the outer bright edge of the doughnuts defined by the set of
limiting apertures in the lens.
Off axis, Andrew's effect becomes more obvious with highly
assymetrical blur patterns possible - ie another form of poor bokeh.
Another way of saying it is to note that bokeh is not constant across
the image plane and different optical effects contribute to different
degrees at various positions.
Tom
Washington, DC
From: chrisplatt@aol.com (ChrisPlatt)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: 40th anniversary of term Bokeh was Re: Bokeh
Date: 10 Nov 1999
I just saw a specially badged Nikkor commemorating "40 Years of Bokeh"...
-Chris
From Rollei Mailing List;
Date: Mon, 20 Mar 2000
From: Phil Stiles pjs@worldpath.net
To: Rollei rollei@mejac.palo-alto.ca.us
Subject: [Rollei] Bokeh
This is the best general reference point for bokeh that I've found.
http://medfmt.8k.com/mf/bokeh.html
One of the early (a few years ago) articles I read claimed that in Japan
the Planar is preferred to the Xenotar because the former has better
bokeh. It was stated that out of focus points in the background are
circular with the Planar, oval with the Schneider. Since I don't have a
Planar, I can't compare, although I can say my Xenotar 2.8 gives great
bokeh. I see a real difference between my old Leica shots (very smooth)
and more recent Nikon (cross-eyed.)
Anyone able to compare Planar vs. Xenotar on this point?
Regards,
Phil Stiles
Date: 07 Nov 1999
From: spoorl@aol.com (SpooRL)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Bokeh of fast, mid FL zooms is generally worse than that of
(even faster) primes
From: "Anthony" mxsmanic@hotmail.com
>I tend not to look at bokeh, because it's all in blurry
>parts of the image, anyway--parts that are largely irrelevant to the
>subject
>of the photo. I'd much rather have a sharp, contrasty, clear lens with
>"bad" bokeh than a mediocre lens with fabulous bokeh.
I use many Nikkors, and collect old ones besides (and these are regular
issue focal lengths--nothing like 8mm fisheyes); my lenses number in
excess of four dozen. As for bokeh, it was never a factor in my purchases.
Nevertheless, I have found myself choosing lenses for macro
bellows/extension rigs based partly upon the smoothness of out-of-focus
area rendition, and this sorting process started long before I ever read
about bokeh here or anywhere else. With macro shots, often the blurred
portions of the picture dominate, and if they are annoying or distracting,
the picture suffers. So it can be a consideration; but more important than
this, as Anthony points out, is that the lens be sharp and contrasty. In
my case bokeh comes into play, but in an incidental way, from observations
based upon actual use. But that's as far a my interest in it goes.
Spoo
From Rollei Mailing List;
Date: Sun, 19 Sep 1999
From: Zdravko Kristic zdravko.kristic1@ri.tel.hr
Subject: Re: [Rollei] Re: Bokeh - what is it in simple terms?
Rea1eye@aol.com wrote:
> Could someone explain in simple terms what is "bokeh" ?
Bokeh is an approximation of the sound of a Japanese word BOKEH
(actually spelled BOKE but pronounced BO-KEH) - there is no
equivalent word in English, AFAIK. It refers to the quality
of the out-of-focus areas of an image. It is usually these parts of
the picture that distinguish the "look and feel" or "signature" of
different types of lenses.
"Good" bokeh seems to come from lenses that produce circular,
smooth-toned out-of-focus shapes. The blurry blobs should maintain its
basic shape and tone. Bad bokeh is when the out of focus blobs are
presented in a DISTRACTING way. A common example is the out of focus
donut blobs of highlights, usually associated with mirror lenses, or
the double images seen in the bokeh of some lenses.
German lenses are praised for good bokeh, while many Japanese
lenses, even from major manufacturers, are not well regarded.
There is nothing you can do to alter the bokeh of an existing lens,
though you may find it changes at different aperture settings.
Recommend you to upload the next file (PDF format) from:
http://fox.nstn.ca/~hmmerk/HMArtls.html#anchor26001
ATVB.pdf (332k), "A Technical View of Bokeh,"
describes what makes the out-of-focus images
different for different lenses.
This is definitely one of the best explanation on bokeh I have seen.
Regards,
Zdravko Kristic
zdravko.kristic1@ri.tel.hr
http://www.geocities.com/SoHo/Gallery/3033
From Rollei Mailing List;
Date: Mon, 20 Sep 1999
From: Vincent Chan v7chan@acs.ryerson.ca
Subject: [Rollei] Bokeh - what is it in simple terms?
Hi all,
I have a web page set up with some Rollei (tessar) shots, to
demonstrate bokeh with different lenses. (as its easier to see than talk
about) The page is at:
http://www.pathcom.com/~vhchan/bokeh.html
From Rollei Mailing List;
Date: Sun, 19 Sep 1999
From: Bob Shell bob@bobshell.com
Subject: Re: [Rollei] Re: Bokeh - what is it in simple terms?
Bokeh is the latest bit of "in" slang in the photo community. Five
years ago nobody had ever heard of it.
It refers to the look of out of focus areas of the image. Good
bokeh is supposed to be a smoother look in these areas.
This is what lenses like the ones from Nikon and Minolta which
let you change the look of the out of focus areas are all about.
Bob
From Rollei Mailing List;
Date: Mon, 20 Sep 1999
From: Godfrey DiGiorgi ramarren@bayarea.net
Subject: re: [Rollei] Re: Bokeh - what is it in simple terms?
> Could someone explain in simple terms what is "bokeh" ?
One of the more lucid discussions of bokeh is available from:
http://www.slonet.org/~dkrehbie/bokeh/bokeh.htm
The person who owns that website, Don Krehbiel, does absolutely
miraculous work with Minox cameras. The author of that particular
article, Pete Zimmerman, is an avid Leica and Minox photographer who is
also a scientist in the field of imaging systems.
Godfrey
From Rollei Mailing List;
Date: Mon, 20 Sep 1999
From: Bob Shell bob@bobshell.com
Subject: Re: [Rollei] Re: Bokeh - what is it in simple terms?
Nikon has one or two of these lenses. I don't recall at the moment
just what they are called, but you turn a ring on the lens to move
internal elements and change the bokeh. I don't think the lenses
sold well in the USA because almost nobody understood what they were
all about. I wrote one up in Shutterbug some time ago but the
differences are very subtle and were hard to see in magazine repro.
You need to look at BIG prints to really see the difference.
Minolta just introduced one earlier this year. Again, I don't have
the literature here at the moment so don't recall exactly the name,
something like Smooth Transfocus Lens. It is a 135 mm in Maxxum
mount but uses manual focus. I have one down at my studio that
Minolta sent me, but I have not even had time to take it out of the
box and look through it.
Both the Nikon and Minolta ones let you control the degree of
smoothness of out of focus areas to a degree.
Bob
....
From Hasselblad Mailing List;
Date: Tue, 21 Sep 1999
From: Jim Brick jim@brick.org
Reply to: hasselblad@kelvin.net
Subject: Re: Zeiss iris diaphrams and Bokah
The best ever dissertation on Bokeh is the May/June 1997 issue of Photo
Techniques. The publisher sells back issues. It is worth tracking down.
It's not the diaphragm that determines what the Japanese have coined
"Bokeh", it's the lens formula (perhaps a little participation by the
iris), which design flaws were left in and which were designed out (you
cannot get rid of all flaws). The new lens designs which eliminate more
and
more flaws, by adding aspheric surfaces and using computers, produce less
acceptable Bokeh. Go to http://www.phototechniques.com for more info.
Jim
olenberger wrote:
> I read the excellent article "A Technical View of Bokeh" by Harold
>Merklinger, where he discusses a hypothetical triangular lens stop and the
>associated effect on out-of-focus highlights: highlights on out-of-focus
>objects in the foreground are small triangles inverted with respect to the
>aperture, and highlights in the background are small triangles having the
>same orientation as the aperture. Presumably the highlights are only the
>most obvious manifestation of the triangular aperture, while the general
>appearance of the out-of-focus objects are affected in less quantifiable
>(and undesireable?) ways. He concluded that "We should probably avoid
>triangles."
> The next day, I was inspecting some slides I shot with my 500CM using a
>Zeiss 80mm CF T* lens (the only 'Blad lens I own). One of the photos was
>taken with the sun to my back, and the image included several out-of-focus
>specular reflections from a background object. Through the loupe I saw that
>these were all distinctly five-sided -- a feature resulting from the
>pentagonal iris diaphram on this lens. (I should note that although there
>were also out-of-focus specular reflections in the foreground, these
>appeared more circular). My questions are 1) Is this bad bokeh? Should we
>"avoid pentagons"? 2) Do all modern Zeiss lenses for the 'Blad use a
>five-bladed iris? 3) Why do the Leitz lenses for my M4 use so many blades
>for the iris that the aperture is essentially a circle, while the Zeiss lens
>uses only five? (The exception is my Leitz 21mm Super Angulon, which has
>only four, but in this case the depth of field is so great that nothing's
>ever much out of focus!)
>-Fritz Olenberger
Newsgroups: rec.photo.equipment.35mm
From: Dante Stella dante@umich.edu
Subject: Re: Nikkor 105mm PURCHASED (REGRETTABLE????)
Date: Mon, 31 May 1999
The same defocus control is available on a most of the AF Zoom-Nikkors.
Just turn the zoom ring a little bit. The DC control is just changing the
effective focal length of the lens slightly by moving an internal element.
Zoom Nikkors are often varifocal (need to be refocused slightly when you
zoom) and this is the same thing.
------------
Dante Stella
On Mon, 31 May 1999, babyjay wrote:
> So in other words your saying return the lens and get the DC (since that
> is my intended purpose)?
>
> And how much more will the auxilary equipment cost me for close ups with
> the DC?
>
> Fred Whitlock wrote:
>
> > I can see this e-mail won't reach you because of the altered
> > e-mail address but you may find this on the newsgroup.
> > Incidentally, you can alter your e-mail address without
> > bothering me (you just won't get any e-mail from me) but you
> > should definitely avoid crossposting. The post is going
> > only to the 35mm group.
> >
> > The 105 Micro and the 105 DC are the same focal length but
> > are for completely different purposes. The 105 micro is
> > designed for closeup photography and the DC Nikkor is
> > designed primarily as a portrait lens. It provides defocus
> > control that alters the look of back or foreground
> > out-of-focus areas or even provides a soft focus effect if
> > adjusted for that purpose.
> >
> > I see no reason not to own both but which one to own depends
> > on the purpose to which you want to put it. The 105 Micro
> > will make portraits, naturally and the DC Nikkor will do
> > closeups with some auxiliary equipment but each is optimized
> > for its intended purpose. Good shooting.
> >
> > Fred
> > Maplewood Photography
> > http://www.maplewoodphoto.com
> > babyjay wrote
> > >I just purchased the Nikkor 105mm f/2.8 micro -AF-D lens
> > >
> > >I'm disappointed in that it's not the lens that has the
> > rotating lens
> > >barrel where you can control the depth of field by a simple
> > twist of the
> > >barrel. Although it does have the micro feature which
> > isn't to bad.
> > >
> > >Now should i return this lens of keep it, and just learn to
> > control my
> > >D.O.Field through the aperture.
> > >I feel like I should spend the extra $500 to get the AF-DC
> > lens
> > >(decentralized focusing, if i'm not mistaken)
> > >
> > >As well, does anybody have the 105mm in the Nikkor line up?
> > If so how
> > >is the lens in terms of 3/4 body shots.
> > >I was told that my lens is great if the person (of focal
> > plane) are in
> > >line, then i'll get consistent sharpness end-to-end.
> > However in the
> > >3dimensional shots where the person may be a little turned
> > to the
> > >camera, it'll be sharp in the center and gradually lose
> > sharpness as it
> > >goes out towards the sides.
> > >
> > >Help me in understanding whether or not i wasted $1,000
> > (lots of zeros)
> > >thanks in advance.
> > >
> > >If this helps any, I'm intending to shoot outdoor portrait
> > style
> > >pictures (from full to 3/4 body shots to head shots)
> > >
> > >again thanks.
Date: Mon, 10 Jul 2000
From: Brian Walsh
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Leica Lens Aberrations -- True or False?
The degree of correction for spherical aberration may be an important
element in lens design; perhaps it's what gives, say, the Contax 85/1.4
and the Pentax FA*85/1.4 lenses their nice "look" ;^)
Regarding design choices to achieve a "Leica look", you might consider
the following from Erwin Putz at
http://www.imx.nl/photosite/leica/courses/course.html
"Current Leica thinking in lens design is to opt for a high contrast and
a high resolution, and many of their lenses show clearly the advantages
of this approach . . . Older lenses had a lower contrast and thus a
lower resolution, not because of particular design goals, but because
the state of the art at those decades did not allow for better imagery."
And:
"When testing a lens on an optical bench, we look at the plane of focus
to assess the image quality. But is is very easy to defocus slightly
before and after the plane of focus. The tester then can simulate the
out of focus areas quite well by looking at the image when defocusing in
small increments. Any optical design program can accomplish this. . . "
And, finally:
"Optical performance is not to be confused with the perception of an
image . . . When talking about image perception we walk into a totally
different realm of lens evaluation. Here personal opinions abound and
every opinion is as good as any other."
(FWIW, I might not recognize a "Leica glow" if it bit me. Even if I
could mount those lenses on my range finder, I don't think the "glow"
would illuminate much more than the middle of the frame :( )
Brian
To respond directly, please remove the underscore from the address.
Colyn wrote:
> carbon_dragon@yahoo.com wrote:
>
> >"...it remains Leitz policy not to design lenses
> >purely to achieve high resolution of flat two dimensional
> >test charts, but deliberately to leave intact a modest
> >degree of aberration and curvature of field to improve the
> >rendition of three dimensional subjects." Collecting and
> >Using Classic Cameras, Ivor Matanle, Thames and Hudson
> >1986.
From Leica Mailing List
Date: Sat, 22 Jul 2000
From: "Erwin Puts" imxputs@knoware.nl
Subject: [Leica] Diffraction limited; bo-ke
.... [diffraction comments]
The topic of bo-ke has been popping up occasionally on this list. The
email by Mr Johnston (provided by Mr Gandy), stating that bo-ke can vary
with a number of parameters, is like flogging a dead horse. The parameters
he cites are the same that govern the representation (or recording) of any
out of focus plane. This is obvious to anyone who knows the difference
between a plane of correct focus and a out-of-focus-plane. Any
out-of-focus plane has a higher aberration content than the plane of
correct focus. In fact, one could describe the effect of the sum of all
optical aberrations on an image as a defocus effect. The out-of-focus
plane then shows a higher level of aberrations than the true focus plane.
The whole idea of bo-ke (at least as interpreted by its students) boils
down to a description of an out-of-focus representation of a section of a
solid (3-D) object by a lens, that has some specified aberration content.
There is a very close relationship between the o-o-f representation and
the level of aberration correction. Most lenses have a different
represestation of o-o-f objects in front of and in back of the plane of
focus. That has nothing to do with bo-ke, but with simple geometry of the
lens.
While bo-ke is a useful concept, it is not a new concept and any lens
designer is aware of its basics. The study of bo-ke is simply the study of
o-o-f representation as governed the optic properties of a lens and by the
residual aberration content of a lens. No new revelations or need to
introduce new concepts. The claim that many current descriptions and
explanations of lens performance are inadequate, because lacking in a
taking account of the bo-ke characteristics that may govern or influence
the visual properties of an image, is like the claim of the famous but
uncomprehensible current French philosophers that a new language and new
concepts are needed to describe social reality.
But I admit that the phenomenology of the picture is a rich breeding
ground for semantic gymnastics.
Erwin.
Date: Tue, 24 Oct 2000
From: lexmack@lava.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Best Bokeh 50's (Links and Thoughts/Suggestions?... :-))
I found this about the Nikkor 50mm lens.
http://www.nikon.co.jp/main/eng/society/nikkor/n02_e.htm
I just test 4 50mm lenses, all Nikkor.
50mm f2 modern, non-ai but multicoated
50mm f1.8 AI,
50mm f1.4 AIs
50mm f1.4 non-ai, single coating.
I shoot test at wide open, f2, 2.8, 4, 5.6, 8.
The bokeh differences are startling!
the 1.4s are slightly 'cross-eyed' at 1.4 but smooth out by f4.
The Non Ai 1.4 is remarkable at f4 and 5.6. Backgound smooth up to
focus.
The 50mm f2 is really nice, much better than I first think.
f4 is super smooth, front and back right up to focus plane.
Let me know if you like to see the images. I think I can send them
From: jsn234@aol.commybrain (Jsn234)
Newsgroups: rec.photo.equipment.35mm
Date: 25 Oct 2000
Subject: Re: Best Bokeh 50's (Links and
Thoughts/Suggestions?... :-))
.....
Thanks lexmack for being one of the few who cared enough to write to
me/others on this topic and for doing your own tests that you are willing
to share:
The article on the 50mm f/2 was excellent. I used and owned this lens and
it is a sleeper optic w/ excellent quality even wide open. I use to use it
for PJ and personal fine art stuff when I used the Nikon system. Every
lens has a unique signature (sharpness, contrast, color, bokeh, etc.) but
the Nikkor AI 50mm f/2 is special among 50mm lenses and has a "character"
like few f/2 50's, super/deadly sharp, yet natural, yet useable wide open.
I happen to like its background bokeh and don't find it either that hars
or de-doubled. I also ike the way it renders bright highlights/reflections
as in that shot of the rose and the leaves at that URL you gave me. I also
find the Pentax 50mm f/1.7 A lens (same formula as the F and FA? versions
of this lens) has both superb sharpness and bokeh and makes me log to,
almost, get back into Pentax again (I don't like the info damn tabs
sticking into the side of the viewfinder, I want no analog or digital
manual scales/etc. intruding into my field of view - the Leica R-4's and
some Minolta XD's had this problem too).
I'd love to see your images/tests. Is there anyway you could put them up
on a web page and give us the link to that page here on the newsgroup? My
e-mail is set up not to accept attachments (for virus and other reasons)
so I'd prefer if you wouldn't mind, setting up a web page then letting us
know the URL to it.
Thanks.
Regards and...
Viva!
From ROllei Mailing List:
Date: Sun, 05 Nov 2000
From: "John A. Lind" jlind@netusa1.net
Subject: Re: Re: [Rollei] Zeiss vs Schneider Diaphragms
Allen Zak wrote:
>Yes, but unlike the Leica V. Contax rivalry, this one really matters.
>
>Allen Zak
Allen,
My most complete answer to diaphragm and "bokeh" is that the best "bokeh"
I've gotten out of any lens (and I have quite a few) is with them shot
wide open, with the diaphragm completely retracted effectively making the
round lens barrel the diaphragm. This obviously gets into the issue of
DOF control as wide open could easily be f/2.8 and unacceptably shallow.
Other than that, in general the more blades the better, and if they have
curved edges to tend to keep the hole round, that's better too. But some
of it is still affected by overall lens formulation and where the
diaphragm is placed in it.
The Leica vs. Contax rivalry did matter then. They were two different
35mm cameras. Neither was overall "best," they each were better than the
other at some things, which probably only served to fuel the Holy War
between them.
The Leitz and CZ lenses for the Leica and Contax had their own
characteristics too, and it depended on what the user wanted from a lens,
which brings me back to the current thread. There is no one right answer
for whose lenses are "best." There is much more to consider in optics
than resolving power and contrast (MTF), and bokeh characteristics, and
some of the criteria may be more important to some users than others,
making the decision different for different users. Here is my complete
list of lens characterisics, and *not* in any order of importance:
1. Resolving power, center and edge across the entire f-stop range
2. Contrast, center and edge across the entire f-stop range
3. Cos^4 falloff across entire f-stop range
4. Flare control
5. Barrel or pincushion distortion
6. Chromatic aberration
7. Astigmatism
8. Coma
9. Bokeh in front of the DOF
10. Bokeh behind the DOF (yes the two _can_ be different!)
11. Flat field
12. How even performance is over the entire f-stop range for all the above
Probably someone can add to this list something that didn't come to mind
as I was typing it in. No single lens I've ever seen does all of this
perfectly (or even "best") meaning no single lens dominates all the rest.
Some of these criteria require design trade-offs. In order to optimize
one of them, one or more of the others must be de-optimized.
Some users _want_ a softer lens with less resolving power and lower
contrast. Other users _require_ a flat field and could not give a
tinker's dam about bokeh. Yet others cannot tolerate any pincushion or
barrel distortion, but don't care about flat field.
You have to decide what aspects of a lens are important for your
application(s) and seek one that does superbly with them, which may not
agree with someone elses priorities.
-- John
[Ed. note: Mr. Erwin Puts is a well-known Leica lens tester and author of
many related photographic articles and resources (e.g., CDROM); these
notes relating to subjective factors vs. objective factors testing and
bokeh tests may be of interest...]
From Leica Mailing List:
Date: Thu, 23 Nov 2000
From: imx imxputs@knoware.nl
Subject: [Leica] Test versus trial?, part 1
> * bear in mind that virtually all "tests" in photography are really just
> trials. But that's okay, since all that most of us want to do anyway is try
> things to see how they work for us. Your goal in all of this should simply
> be to learn the way your lenses behave, so that (if you prefer to) you can
> accomodate their weaknesses and play to their strengths when you're
> shooting, and not find yourself unpleasantly surprised by results you didn't
> anticipate. (This is also a goal of learning about other aspects of
> photographic technique.)
The above citation might be expanded and annotated to reflect the true
nature and purpose of several methods of factfinding. Generally all
photographers are experimenters and when they change a film, or a lens, or
a negative developer or a printing paper individually or as a set, they
try to change variables, of which they assume that they will influence the
resulting image in the preferred direction. No one will act in such a way
as to randomly change the variables without any guiding principle.
The goal of any experiment or theoretical study is to explore and explain
the outcome of a photogrtaphic process by finding the true causes that
influence the result in a significant way. Only if you know what effect a
certain change in a varibable has on the result, can we accurately predict
the result and avoid unhappy surprises.
To measure is to know and to know is to predict, it is that simple. The
question then is: if we want to predict and anticipate the results of
changes in the many variables that comprise the photographic technique,
how can we proceed in a reliable way?
If you do not have a clue what causes are influencing the required result,
you will start with a series of trials, changing one variable at a time
and noting the results. To make such a process worthwile, you need to keep
notes and record any change and presumed effect in order to see a pattern
emerge. Without making notes and searching for patterns, you are walking
in the dark.
Given the large amount of photographic literature about every technical
aspect, the trial stage can be skipped in most cases and we can go to true
experimentation. That is: predicting from theory which variables will
effect the outcome and in what amount. This last addition is crucial:
knowing that there is some impact by a variable on a result is not enough:
to predict we need exact information about direction and magnitude of the
change in the variable. We know for sure that a change in temperature of
the developer will affect the density, by by which amount. The same for
agitation rythm:
we know it might have impact on the grain structure, but how much impact
and are there other factors that will negate this effect.
Experiments then are best for fact finding in practical situations but to
make the results worthwhile, we need to do:
a lot of experiments to make sure we have a statistically significant
pattern
make copious notes of all changes during the experiments
change variables one at a time to control and isolate the cause to be
studied
A test is the natural extension to an experiment, with one proviso: you
use instrumentation to measure the phenomena you wish to have data on. And
you use a test protocol to make sure that your measurements are valid. The
upshot is simple: a trial is an insufficient base on which to draw any
conclusion, with the exception of heuristic idea forming.
To give evidential support to these ideas, we need controlled
experimentation and a modicum of theory to guide us.
If we do not proceed according to the time honored rules of fact gathering
and corroboration of theories and hypotheses, we stay ignorant.
Of course, it is every individual's right to accept and support with force
whatever conclusions he is happy to believe in.
If this were the universal approach to photographic technique, however, we
would still be in the infancy of photographic lore, like the ideas that
resolution is the important criterium for optical quality, or that high
dilutions in developers generally increases the definition, or that
pushing increases the speed of a film, etc.
Most of these ideas were based on evidence so scanty that a nude model
would look fully dressed.
Let us illustrate all of this with the bokeh discussion.
See Part 2
Erwin
From Leica Mailing List:
Date: Thu, 23 Nov 2000
From: imx imxputs@knoware.nl
Subject: [Leica] Test versus trial?, part 2
Bokeh is generally defined in a very loose way, which in itself hinders a
good discussion of the phenomenon. Often bokeh is presented as a recent
discovery which is not true. The intra- and extra focal out-of-focus blur
is a wellknown topic in every optical handbook. New is only the idea that
these blur effects have a subjective dimension and are supposed to be
instrumental for the qualitative appreciation of a picture.
Blur has a real and a subjective aspect. The analysis of bo-keh is in
itself simple: we know from optical theory how the focused rays will be
distributed in the unsharpness areas in front of an behind the plane of
best focus. We can also calculate the energy distibution within the blur
circles, located on the several unsharpness planes at any required distnce
form the plane of focus. This is Canon's approach and by studying the
changes in energy distribution patterns, they can predict what effect will
result. The optical cause of these different energy distributions within
the blur circle is the level of correction of spherical aberration. So if
I know the level of SA in a lens, I can safely predict the way the image
will be reproduced in the unsharpnes plane.
An optical manual from 1933 (no typo!) already gives a lucid account of
this phenomenon.
If we would do a series of experiments with our lenses to see how they
reproduce the out of focus blur circles and how these have impact on the
way the out of focus images are shaping (deforming) the image structure
and details.
As it seems the case that the characteristics of the image (shape,
structure of details, contrast) in the out-of-focus plane are decisive for
the type of blurring in the rendition of out-of-focus foreground and
background and the perception of the eye to this type of blurring, we need
to establish some clear guidelines what structures we have to look at.
Some experts note that bokeh is confined to out-of-focus highlights, which
are influenced by optical design and number of diaphragm blades. But not
one experiment (and I checked more than a hundred sites on internet to
become familiar with what is the general opinion) has conclusively decided
which, if any, of these supposed causes is the real one. Others hold that
bokeh is only relevant for macro- and portrait photography.
Bokeh is variously described as "hard edged blurs", "abrupt transitions
from light to dark", "poor definition in out of focus objects", " doubling
of out of focus lines","soft edged blurs", "smooth even transitions in
areas of contrast". Then we have all kinds of descriptions of the blur
spot itself: donut shaped, butterfly shaped etc. Not one description
refers to focal length, aperture, distance and relative position of fore
and background location. Now "(fore)background" is not an isolated plane,
but a portion of reality with depth. So where exactly are you loking at
when discussing bokeh?
As the origin of bokeh is the blur circle and its physical shape,
dimension and energy distribution, any study of bokeh would have to
control the usual blur circle effects: focal length, distance to plane of
focus, distances from PoF and print magnification. Enlarge a negative 5
times or twenty times and the size of the blur circle changes and so the
relative diatance from unsharpness blyr to PoF also changes. Diffeernt
portions of the out of focus image are affected.
To get ahead in this barrage of definitions and options, we need to
establish a common situation. You can not compare a picture taken with a
50mm at 5.6 of a girl at 5 meters in a sunny environment and enlarged 8
times with the background at 15 meters, with a picture of a 90mm lens at 4
of a flower at 1 meters in contre jour to get nice specular highlights in
the background, where the background is at 3 meters and the enlargement is
15 times. And so on.
Without a description of an experimental situation, that can be accurately
reproduced in several testsessions, without the definition of the camera
position and distance, aperture and the definition of the specific o-o-f
planes where the bokeh effect should be studied, without specified
enlargement factors, without a specification of the blur effects to look
for and so on, we are simply getting nowhere in the direction of studying
the phenomenon.
I do assume, wading through hundreds of pages of lens descriptions by
people who discuss bokeh, that concepts like "openness", "surrealness",
"airbrush creamy smooth" and so on are all attempts to describe the
impression that the observer gets from looking at a picture. Such an
approach makes for a fine discussion that may be satisfactory for the
participants, but is so open-ended and vague that I wonder what the goal
is here.
If you pick up a art book like " how to look at photographs" or 'The
photograph", the content and meaning of a photograph is discussed in terms
of visual language and the whole weight of visual art critique.
If you pick up an optical book, you are treated with physics, and the
fundamentals of visual perception.
Both approaches cover the whole spectrum of how to analyse and discuss a
photograph. And it is very enlightening to study both fields.
The bokeh discussion on the contrary is quite confusing and has no added
value (at least not in the present state of vagueness and lack of any
experimental base). In the Japanese culture, the bokeh discussion may be
of great value as it fits in in their tradition of visual awareness and
sensitivity.
If we wish to improve the quality of the bokeh discussion, we should move
beyond the trial stage and do some substantial fact finding based on
repeatible experiments.
Erwin
Date: Thu, 14 Dec 2000
From: "Joseph S. Wisniewski" wiz@netfrog.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: "soft" lenses and other general ramblings.
PBurian wrote:
> Some do mention the use of 9 (vs. fewer) aperture blades to make out
> of focus highlights appear round - at any aperture.
>
> I certainly understand that concept.
But that's only a small part of Bokeh. A very important part is where
the aperture blades are in the optical path. This can cause the circle
of confusion to have a soft edge or sharp edge, a bright center or dark
center, color fringes, etc. Six blades in a spot with good soft edges
may be much less annoying than 9 blades in a razor sharp circle. The
lense design itself also helps determine where the "best" bokeh can be
found.
Some really "bad" bokeh (often seen on super wide angle lenses) has a
circle of confusion with a dim center and a bright edge. Sort of like
what you see in a mirror lense, but not as severe. It has something to
do with the things designers do in a super wide lense to keep the edges
from having light falloff. This kind of Bokeh will render an out of
focus line as two parallel lines, and can look very strange. It renders
bright points as rings, and can really make a candlelight picture look
weird. On the other hand, it makes water droplets on a leave look extra
sparkley.
"Sharp edged" bokeh can render a straight line (even out of focus) as a
straight line, and often makes the background more annoying than soft
edged bokeh.
I guess, in general, what most people call "good bokeh" would be a lense
that renders an out of focus area as round, with soft edges, and a
center that is at least as bright as the edge.
Oddly enough, I've known the word "bokeh" less than a year, but I've
been very much aware of the concept "the quality of the out of focus
image" for decades. Probably since I bought a mirror lense in 1985, and
had to keep an eye on situations that caused it's particular bokeh to be
a problem. This got me looking at the bokeh of my other lenses, and even
learning the "read" the bokeh of other people's photographs.
In retrospect, I suppose "bokeh" is probably a better term than the
acronym QOOFI (quality of out of focus images), OOFI, etc.
> Perhaps someone will actually produce an article, showing good vs. bad
> bokeh in actual images. The few images that I have seen don't seem to
> help me decide.
Perhaps because there's no such thing as absolute "good" or "evil" in
bokeh. Think of it as the shape of the paintbrush, or maybe the brush
stroke itself. I've heard people refer to the ring highlights of a
mirror lense as beautiful, and others call it trash. It's all a matter
of taste. You may think the bokeh is dreadful, and the client will fall
in love with the little halos of light in your jewelry ad work.
It's like a lot of the experiments run by audiophiles (the folks with
$10,000 stereo systems). Sure, you can prove that there's a difference
noticeable by a trained listener. But you can't "prove" that the
difference is an actual improvement in the listening experience.
But I did see an example which illustrated the "parallel line" problem
very well with overhead wires in a landscape. They definitely looked
less annoying in the "good bokeh" picture. If I come across the URL
again, I'll forward it.
I know I'm going to regret writing this, because it gives the bokeh
snobs language equivalent to a wine snob. Ah, the Nikon 85mm f1.4 has a
fine bokeh, round, full in the center, with a melting soft edge and a
wonderful aftertaste of cherries and leather.
Ciao!
Joe
From Leica Mailing List;
Date: Sat, 23 Dec 2000
From: Jesse Hellman hellman@home.com
Subject: Re: [Leica] don't laugh...
Although he doesn't use the word "bokeh" in his article on the Summicron
28mm F/2, Erwin Puts writes "There is a certain harshness in the out of
focus rendition that is typical of modern Leica lenses. It is related to
the level of aberration correction."
http://www.imx.nl/photosite/leica/mseries/testm/m2-28.html
Jesse
From Nikon MF Mailing List:
Date: Sat, 23 Dec 2000
From: Mackie mackie@columbus.rr.com
Subject: Re: Bokeh
Bokeh means the 'out-of-focus' portion of the photo. Most used when
isolating the subject from its surroundings or background. When you are
using a large f-stop, you have a shallower depth-of-field.
To me its part of the aesthetics of the image.
There is an example of a blurred background, with sparkling water on the
first image of this page:
http://www.geocities.com/makies35mm/highbanks.htm [gone as of 9/2002]
Hope this helps. My personal definition has been gained through
experience and discussions with others. Not through a formal means of
education.
Mackie
http://mackie-z.com
From Nikon MF Mailing List:
Date: Sat, 23 Dec 2000
From: rcochran@lanset.com
Subject: Re: Bokeh
--- In NikonMF@egroups.com, Nikon Cameras NikonCameras@a... wrote:
> Not to sound ignorant, but I only have heard this word here in
> emails. What exactly does "bokeh" mean? I have not found a
> reference to this in any of my photo books. Thank you.
Nikon makes two lenses that allow you to control bokeh. The "DC"
lenses are available in 135 and 200mm focal lengths, but alas, only in
autofocus versions (though they'll work fine on MF cameras).
To see them in action, changing the bokeh of a scene, see
http://129.105.37.137/photo_equipment.html [gone as of 9/2002]
Scroll down about halfway to the pictures of the pretty girl. Look at
how the out-of-focus background and foreground changes its softeness
in the various photos. The depth of field is the same, and the shape
of the aperture is the same, but the smoothness (that is, the "bokeh")
is visibly different.
--Rich
From Leica Mailing List
Date: Thu, 28 Dec 2000
From: Martin Howard howard.390@osu.edu
Subject: Re: [Leica] Bokeh controversy
Dan Honemann offered the challenge:
> Okay, so what are your favorite bokeh lenses?
I haven't owned that many lenses, but from personal experience and looking
at photographs shot with known lenses (assuming no lies in the sources)
that I haven't owned I'd say that the list includes (in no particular
order):
Nikon 105mm f/2.5 second version
Leica 35mm f/2 Summicron 8-element (first version?)
Leica 35mm f/2.8 and f/3.5 Summarons
Leica M 50mm f/1.4 Summilux
Leica M 50mm f/2 Summicron (DR generation)
Leica R 60mm f/2.8 Macro-Elmarit
Leica R 80mm f/1.4 Summilux
Leica R 90mm f/2.8 Elmarit (first generation)
Leica M 90mm f/2.0 Summicron (first generation)
Leica R 135mm f/2.8 Elmarit
Contax 85mm f/1.4 SLR lens (several people have claimed that it's
worth buying a Contax SLR just for the bokeh of this single
lens alone!)
Contax 135mm f/2.8 SLR lens
As a general rule, long and wide tele-lenses seem to have smoother bokeh
in general (I'm thinking of 300mm f/2.8, 400mm f/2.8, 400mm f/4, 600mm
f/4, etc). I guess it has something to do with the lens designs.
Another general rule appears to be that lenses with a symmetrical (or near
symmetrical) design produce smoother bokeh. Often, focal lenghts around
50-85mm will be such a design (and older 35s). The early 90mm Elmarit-R
was a (near?) symmetrical design. Yet, the 135mm Elmarit is not, but has
wonderfully smooth tonal qualities in the OOF parts of an image (check out
Doug Herr's page on it, or Skip Bolen's Jazz photography with that lens).
The 75mm f/1.4 Summilux-M is an interesting beast. Sometimes is looks
fabulous, other times the bokeh is not too brilliant. I think it is
sensitive to the kind of background: broken leaves do not seem to fare
well. The 75mm f/2.5 VoigtlSnder looks interesting, from seeing some of
Johnny B's (or D's) shots in Human Traffic. Again, it appears to be
somewhat sensitive to the background.
Zooms are trickier. They generally seem to exhibit more complex bokeh
(not necessarily "double-eyed", but certainly not smooth) than prime
lenses. However, what I've seen of shots from the Contax SLR and Leica R
zooms, they seem to have particularly nice bokeh, approaching that of good
primes.
If I recall correctly, medium-tele (80-135mm) Canon FD primes have pretty
good bokeh (the fast ones, that is), and the current crop of fast EOS
mid-tele primes seem reasonably OK -- but not up to Leica R or Contax SLR
standards.
Nikon doesn't seem to know it exists, or care about it. Their lenses
appear to be hit-and-miss. They recently released two lenses with
"defocus control", the 105mm f/2 and 135mm f/2, which supposedly allows
you to alter the quality of the OOF parts of the image. I haven't used
them. Their 85mm f/1.4 reportedly has nice bokeh, what I've seen of the
60mm macro looks pretty good, but general consensus has it that the 105mm
f/2.5 is the best they've ever produced with regard to bokeh. Superb
portrait lens. Wish I could get it in Leica R mount.
Minolta issued a lens somewhere around the 135mm focal length with a
"soft-focus" or "defocus" control. Their approach is much more low-tech
than Nikons, and actually rather clever. They include a second aperture
in the lens design, one that dims the edges of the OOF discs -- producing
a gradual fall-off of light intensity towards the edge of the disc.
Smart. I've seen shots (albeit in magazines) that look pretty good with
it. Minolta's G series of SLR AF lenses also seem to fare pretty well
(what little I've seen of it: no-one seems to use Minolta these days).
In MF, Bronica seems to fair better than Hasselblad, despite the latter
being Zeiss. I can't explain it, I'm just reporting what I've seen after
pouring over images from the two lens systems for hours on end.
Bad examples of bokeh (if you like smooth bokeh) are exhibited by:
Nikon AIS/AF 50mm f/1.4
Hasselblad 150mm f/4 Sonnar (yeah -- used for portraits, I know ;)
VoightlSnder 50mm f/1.5 Nokton (I put an 'h' in the name specifically
for Marc James Small's enjoyment ;)
Pretty much any consumer-grade f/4-f/5.6 SLR zoom from Nikon
M.
- --
Martin Howard
From Rangefinder Mailing LIst:
Date: Fri, 2 Feb 2001
From: Kaneko Yutaka Yutaka.Kaneko@tetrapak.com
Subject: RE: [RF List] bokeh
Yes, the origin of bokeh is Japanese. I learned the word is imported into
American English already. The term in photographing is exactly John
mentioned below. It discusses the blur background where it shouldn't be
clear as the main subject. When we compare lenses, sharply focused subject
is a matter of course, but beautiful bokeh behind the main subject is what
important to judge good lens now days.
I am not intended to make Japanese lesson here, but the infinitive of
bokeh is bokehru that could be used to human being as well. When someone
having a short memory due to his/her age, we call he/she is bokehru.
His/her brain become not sharp, and unclear as a photo.
Infinitive: bokehru
Past tense: bokehta
Past perfect: bokehtamama
Noun: bokeh
Synonym: boyakasu
Pretending ignorance: tobokehru
This isn't the topics to discuss here in RF list, but I tobokehru.
Regards,
Yutaka Kaneko
...
From: Gromit paal88@my-deja.com
Newsgroups: rec.photo.equipment.35mm
Date: Fri, 15 Dec 2000
Subject: Re: bad bokeh ex. URL Re: "soft" lenses and other general
ramblings.
rmonagha@smu.edu (Robert Monaghan) wrote:
> for you, Peter, no problem ;-) see Luis Lopez Penabad's example of really
> bad bokeh from a zoom lens (not mirror) at:
>
> http://medfmt.8k.com/mf/bokeh.html
>
> there are also examples and links to other sites (V. Chan's etc.) showing
> variations and some good/bad etc.
BTW Pentax have recently made a new series (Limited) of lenses that
offers the pleasant bokeh and almost a stereoscopic three-dimentional
effect. This is done by fine tuning aberations. In addition, they offer
astounding resolution.
From Rollei Mailing List:
Date: Wed, 28 Mar 2001
From: todd todd_belcher@telus.net
Subject: Re: [Rollei] Re: Bokeh
Bokashi is the Japanese word for gradation.
Todd
rec.photo.equipment.35mm
From: ll.clark@verizon.net
Date: Wed Apr 25 2001
Subject: Re: bokeh and "glow" ;-) Re: why 300% better Leica aerial resolution
As a footnote to your interesting post, I'd like to concur with your
remarks about lenses. I was also encouraged to see some of the Olympus
lenses get the recognition they deserve; and to recommend to you two
others -- the f5.0/200mm and the f2.0/90mm that also share the quality of
"glow," or an impression of three-dimensionality, common to the best Leitz
and Zeiss glass. It shows up in the wonderful Sonnar in the Rollei 35,
too.
les clark / edgewater, nj / usa
From Nikon Mailing List;
Date: Thu, 26 Apr 2001
From: "Brian H" bkharris@carolina.rr.com
Subject: Re: [NIKON] What is "bokeh"?
Here are some good links on "bokeh". They were taken from a post on the
Leica list last week.
Brian
http://www.slonet.org/~dkrehbie/bokeh/bokeh.htm
http://medfmt.8k.com/mf/bokeh.html
http://www.pathcom.com/~vhchan/bokeh.html
http://www.geocities.com/Athens/Atlantis/4628/bokeh.html
http://www.kenrockwell.com/bokeh.htm
http://www.flarg.com/bokeh.html
http://fox.nstn.ca/~hmmerk/ATVB.pdf
From Nikon MF Mailing list;
Date: Sun, 29 Apr 2001
From: Godfrey DiGiorgi ramarren@bayarea.net
Subject: Re: Creamy-sharp lenses
The 24/2.8 and the 180/2.8 are in that class of goodness. I also like
the 85/2 AI-S (although others have seen fit to condemn it). The old
pre-AI 85/1.8 is marvelous. The 20/3.5 AI-S (52mm) is another lens I
fell in love with instantly.
Godfrey
>To those of you who know exactly what I'm talking about my question
>is this: are there any other Nikon lenses with this same magic?
From Nikon MF Mailing List;
Date: Mon, 30 Apr 2001
From: Nikon Cameras NikonCameras@asean-mail.com
Subject: Re: Creamy-sharp lenses
If you think that the 105mm f/2.5 lens is good, get your hands on the
105mm f/1.8 -- it makes the 2.5 look like an amateur's lens!!! Besides
this lens, get your hands on a 35mm f/1.4; the 85mm f/1.8 pre-AI (or
AI'd); the 180 f/2.8 ED IF AI; the 135mm f/2; and the 58mm f/1.2 Noct.
These are the lenses that brings us kids to the Nikon candy store!!!!!!
...
From Nikon MF Mailing List;
Date: Tue, 1 May 2001
From: "Roland Vink" roland.vink@aut.ac.nz
Subject: Re: Creamy-sharp lenses
> To those of you who know exactly what I'm talking about my question is
> this: are there any other Nikon lenses with this same magic?
The creamy softness may be something to do with the smooth rendering
of out of focus objects in the background (bokeh).
This is due to the optical design which slightly under-corrects for
spherical abberations, the result is that an out of focus highlights in
the background have softly feathered edges which blend smoothly together.
The AF 105/2.8 micro at the same aperture setting renders the same
highlights with hard edges so the background appears more contrasty and
cluttered, out of focus lines appear doubled.
Unfortunately most Nikkors are overcompensated for spherical
abberations. This helps to give the lenses more appearance of contrast
and "snap" but the bokeh is usually poor.
Of the lenses I have tried, the AIS 28/2.8 and 28/2 are more or less
neutral.
The 35/2 is not very smooth, the 35/1.4 is good - probably the best bokeh
of any Nikon standard lens.
All of the 50mm and 55mm lenses have harsh background rendering, although
the latest 50/1.8 (series-E, late AIS and AF versions) are not so bad.
My 85/2 is not great either, the only fault of an otherwise fine portrait
lens. The pre-AI 85/1.8 is good, one of the reasons this lens is well
regarded. The AF 85/1.4 is reputed to be excellent.
The 105/2.5 is one of the best lenses Nikon has made. The 105/1.8 can
produce images with very blurred backgrounds due to the larger
aperture, but I found the rendering of the background was not as
smooth as the 105/2.5 at similar apertures. The 105/4 micro and AF
105/2.8 micro are not great either, although they are very sharp.
The series-E 100/2.8 is fairly good, but not creamy like the 105/2.5.
The AIS 135/2.8 is neutral, not great, but not bad either.
The AIS 200/4 and 200/4 micro are also ok, the longer focal length helps
to make background appear more smooth.
The 300/4.5 EDIF can produce harsh backgrounds, but due to the long
focal length, narrow angle of view, and by selecting the background
with care, you can produce great results.
The series-E 75-150 appears to be good sometimes, and not so good at
others - I haven't figures this one out.
Hope this helps,
Roland
From Leica Mailing List;
Date: Tue, 29 May 2001
From: Jim Brick jim_brick@agilent.com
Subject: [Leica] Re: Tri-elmar and Bokeh
Bokeh, is truly a personal and very subjective property. It does not seem
to be congruent with modern lens design. Erwin has never been a proponent
of describing Bokeh and to attempt to quantify it would be a lifetime job.
And in the end, it is all subjective to each viewer. It is not like
quantifying resolution or centering or pincushion. For Erwin (or anyone
else) to attempt to put a qualitative value on Bokeh, is not in anyone's
interest. It cannot be done.
Jim
....
From Leica Mailing List;
Date: Tue, 29 May 2001
From: Jim Brick jim_brick@agilent.com
Subject: [Leica] RE: Re: Tri-elmar and Bokeh
Yes, I am a fan of nice and smooth out of focus areas. I like this in the
older lenses much better than the newer lenses. But I will probably like
something that many people dislike, and vise versa. I like Jazz,
classical, R&B, Rock & Roll, but I hate Dixieland.
Studying the physical properties of lenses such as sharpness, coma,
centering, etc, is cut and dried. Attempting to explain the "Bokeh" of a
lens is, basically, impossible unless you are Japanese and have been
studying the "look" of Bokeh for a long time.
I have read the (translated) Japanese lens reports where Bokeh is
evaluated. There is a whole language built around the phenomena. In order
to understand it, you have to have a working history with Bokeh. I didn't
understand it.
To put it in perspective, FTlix, please explain in words that all LUGgers
will understand, what the Bokeh of the Tri-Elmar looks like.
It is much more than "a smooth blurred background" or a "harsh blurred
background."
Erwin is correct in making the simplest possible statements. Such as "old
lenses have a better Bokeh than new lenses."
Jim
FTlix L=pez de Maturana wrote:
>But Jim, whatever bokeh could be, subjetive or not, you trust the Erwin
>statement that old lenses had better one?
>
>Kind regards
>
>FTlix
>
>PS I think that is in fact the nicest blurred background available to stand
>out the main subject. As far as nicest is not objective cannot be measured.
>But *it* is of interest for instance to get nicer portraits.
[Ed. note: first, there was microcontrast versus contrast, now there is
"cohesion" versus bokeh ;-)]
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 29 Jun 2001
Subject: Re: SQF Testing - was Re: Pop Photo tests Tamron 24-135
>Incidently, another phenomenon that I have encountered is, that with
>the really good lenses, the sharpness (contrast and resolution) of the
>lens remains high even when focus is not absolutely precise (focusing
>manually or with AF is not always the most precise). Whereas, with a
>poor or mediocre lens sharpness seems to fall off much more rapidly as
>focus becomes less precise. There is absolutely no way for me to
>quantify or even explain this observation, but I am convinced of its
>truth. I would be interested if others have had a similar experience.
Can't remember the URL (Earl Putz's website?) but Leica lenses seem to
have this "integrity/cohesion of out of focus background detail" that you
refer to. It might be due to lower (spherical/chromatic/etc.) aberrations
and/or perhaps the lens is designed for a smaller and/or smaller spreading
circle of confusion - just a geuss. This phenomenon (oof b.g.
integrity/cohesion) is probably not limited to Leica lenses (they just
charge more for it ;-) ;-).
:-)
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From Nikon MF Mailing List;
Date: Fri, 20 Jul 2001
From: Tony P nikon@scalby.freeserve.co.uk
Subject: Re: Digest Number 1115
>From: "Rick Housh" rick@housh.net
>To: NikonMF@yahoogroups.com
>Sent: Wednesday, July 18, 2001
>Subject: [NikonMF] VoigtlSnder AI/S mount lenses
>
>
>I notice the Cosina-manufactured VoigtlSnder Color-Heliar SL 75mm f/2.5
>lens is available in a Nikon AI/S mount, as well as others, and the
>Apolanthar 125 mm f/2.5 macro soon will be out, if it's not already.
>
>The Color-Heliar 75 and an Apolanthar 90 have previously been available in
>Leica thread mounts and have very good reputations from what I hear, but I
>haven't seen any reports on the Apolanthar 125 macro at all.
>
>Has anyone seen any reports on these two new AI/S mount lenses from
>VoigtlSnder? It's never bad news to see a new Nikon MF mount lens from a
>quality manufacturer, but the 125 macro looks particularly tempting, and
>the prices are very good, compared to Nikkor glass.
Hi Rick,
I had one of the VoigtlSnder 75mm lenses in AIS mount on trial for a
week several months ago. It was a good, but not outstanding lens. The
slides were sharp but contrast was not as good as my 85mm f/1.8 AF
Nikkor. Surprisingly, neither was the bokeh. As this is a focal length
that's often purchased for portraiture I was disappointed.
I've used many "portrait lenses" in the 75-135mm range, including (in
the past year):
75mm f/2.5 VoigtlSnder Color-Heliar85mm f/1.8 AF Nikkor
85mm f/1.4 AIS Nikkor
90mm f/2.5 and f/2.8 Tamron SP Macro
100mm f/2.8 Nikon Series E
105mm f/1.8 AIS Nikkor
105mm f/2.5 AI Nikkor
135mm f/2 DC AF Nikkor
75-150mm f/3.5 Nikon Series E
For sharpness and bokeh my top three recommendations would be:
1. 85mm f/1.4 AIS Nikkor (excellent sharpness and sublime bokeh)
2. 135mm f/2 DC AF Nikkor (excellent sharpness and bokeh *control*!)
3. 105mm f/2.5 AI Nikkor (excellent sharpness and sublime bokeh)
The 105mm f/2.5 AIS Nikkor is still available new at an excellent price
for such a fine lens.
The "best of the rest" are:
85mm f/1.8 AF Nikkor (the bokeh doesn't please everyone)
100mm f/2.8 Nikon Series E (a beauty, but prone to flare)
75-150mm f/3.5 Nikon Series E (sublime optics, but lacks the overall
robustness and longevity of contemporary Nikkor AIS lenses)
The Tamron is also a fine performer, unusual in that it combines good
sharpness with excellent bokeh in a macro lens. I say that's unusual
because macro lenses usually have good sharpness but bad bokeh.
I've yet to decide which will be my first choice portrait lens, but if
the 75-150mm f/3.5 Nikon Series E had been made as an AIS Nikkor I would
look no further. It combines 85mm, 105mm and 135mm in one lens with
*outstanding* optical performance for a zoom.
--
Tony P
From Nikon Mailing List:
Date: Sun, 13 May 2001
From: "L Shepherd" Shepherdlen@btinternet.com
Subject: Re: [NIKON] Re:Defocus control
From: "Edwin Hurwitz" edwin@indra.com
> I have the 105 DC and as far as I can tell, it realigns the elements
> so that the focal plane shifts in the depth of field (instead of
> having it constantly 1/3 of the way back). This way, you can throw
> more of your background or foreground out of focus, depending on your
> needs. You can accomplish the same thing on other lenses by
> carefully focusing on a plane in front of or behind the subject and
> calculating the depth of field, but this makes it way easier. Truth
> be told, I hardly use this feature at all, but it is a great lens (it
> is an insurance replacement for a regular 105 2.5 AI for me).
Hi Edwin
Sorry I don't agree with most of that. The DC lenses work by controling
the amount of spherical abberation in the foreground or background which
is a different effect To focusing in front or behind the centre of
interest. I agree focusing just in front can produce a very acceptable
portrait.
Nikon don't help users understand how it works by only mentioning it on
page 7 of the current lens catalogue and not mentioning it with any
discription of the lens or in the lens instructions.
Also depth of field is not constantly one third in or out. It is only one
third in front at one quarter of HD which is at one specific distance for
each aperture on a prime lens.
At one tenth of HD or closer for photographic purposes depth is equal both
sides, and at HD 99% (aprox) of depth is behind the point of focus.
The shape of depth of field (i.e. the percentage sharp in front and behind
the point of focus) always varies with focus distance.
Len Shepherd.
To: camera-fix@yahoogroups.com>
From: William Gartin william_gartin@mac.com>
Date: Tue, 20 Nov 2001
Subject: Re: [camera-fix] Re: Zeiss Ikon Contaflex
Mark Stuart wrote:
> I believe 'bokeh' (USA only?) describes the out-of-focus areas of the image,
> particularly the out-of-focus highlights. Some lenses give
>
I'm not positive, but I always thought "Bokeh" was an Asian term.
> the word. Only because I can't pronounce it... ;)
>
I am also unsure of the correct pronunciation, but I've always pronounced it
"bow-kuh". Feel free to correct me on this.
> --- In camera-fix@y..., camfix@w... wrote:
>
>> believe this means a sort of overall "sharpness" and if I have it right this
>> is more common in European lenses than it is in the Orential counterparts. My
>> apoligies to Bob if I got that wrong. Good luck Everett
>>
Ken Rockwell has an excellent explanation of bokeh on this page at his
website:
http://www.kenrockwell.com/tech/bokeh.htm>
You might also want to take a look at Harold M. Merklinger's explanation on
the Luminous Landscape site at:
http://www.luminous-landscape.com/bokeh.htm>
--
William Gartin william_gartin@mac.com>
Date: Thu, 06 Sep 2001
Subject: Re: Aperture blades and Bokah
From: Peter Rosenthal petroffski@mac.com>
To: hasselblad@kelvin.net>
The actual number of the blades is dictated by the need to have an odd
number so as to control the effects of diffraction and the physical size
limitations of the shutter relative to the maximum aperture. I can't
imagine acceleration has much to do with it since Hassy uses one honkin'
spring to stop them down and the mass is not changed too much as many small
blades have virtually the same mass a few large ones. Friction on the other
hand...
Curvature of the aperture blades spreads the diffraction (read: loss of
contrast) over the entire frame. Straight sections concentrate it in the
specular hilites as noted. Since EVERYTHING in photography is a compromise
of one sort or another... decisions on such things are made to minimize
problems for the greatest number of shooters. Just my opinion.
Peter
--
Peter Rosenthal
PR Camera Repair
111 E. Aspen #1
Flagstaff, AZ 86001
928 779-5263
> Rei Shinozuka wrote:
>> my 50 and 80 C's and 100 and 150 CF's have 5-blade apertures.
>> the 80 planar on my rollei 2.8F also has a 5-blade aperture.
>>
>> it's been postulated here that the need to accelerate larger blades
>> relative to 35mm auto-diaphrams may have something to do with the number
>> of blades. this wouldn't apply to the TLR, of course.
>
> So are you sayiing that folks are thinking that there are only five
> apeture blades because of the size of the blades. I just do not
> buy into that theory. I would think it would be easier to move ten
> smaller blades then five larger ones. And what about giving the
> blades a bit of a curve to round out the apeture?
Date: Fri, 07 Sep 2001
To: hasselblad@kelvin.net, hasselblad@kelvin.net
From: Jim Brick jim_brick@agilent.com>
Subject: Re: Aperture blades and Bokah (Bokeh)
Just as a general information point, lens "Bokeh" is a lens design formula
property. It has nothing to do with the diaphragm type, shape, or number of
blades.
Lens Bokeh is usually judged with the lens wide open (or nearly so) and the
diaphragm is most likely not even in the light path.
Old formula Leica lenses are the Bokeh "standard" according to the Japanese
lens test reports that evaluate this phenomenon. New computer aided
designed lenses, ASPH, and APO lenses, are generally thought to have Bokeh
inferior to the old Leica lenses.
Jim
From: "Austin Franklin" darkroom@ix.netcom.com>
To: hasselblad@kelvin.net
Subject: RE: Aperture blades and Bokah (Bokeh)
Date: Fri, 7 Sep 2001
You might want to read this article:
http://www.darkroom.com/MiscDocs/bokeh.pdf
I believe it differs from your conclusion.
> -----Original Message-----
>
> Just as a general information point, lens "Bokeh" is a lens
> design formula
> property. It has nothing to do with the diaphragm type, shape, or
> number of
> blades.
>
> snip
>
> Jim
Date: Fri, 07 Sep 2001
To: hasselblad@kelvin.net, hasselblad@kelvin.net>
From: Jim Brick jim_brick@agilent.com>
Subject: RE: Aperture blades and Bokah (Bokeh)
I read all of the Bokeh articles in "Photo Techniques" a few years ago and
they, if I remember correctly, discussed the different types of Bokeh as
well as the root cause of these Bokeh. It was my impression from reading
those articles and talking to Erwin that lens formula has more impact on
Bokeh than any mechanical external device. The 35/1.4 ASPH has much harsher
and not as nice Bokeh as does the older non ASPH versions of the same lens.
Likewise the old Summicron formula have better Bokeh than the latest
Summicrons. And the diaphragm is not that much different, if different at all.
Jim
Austin Franklin wrote:
>You might want to read this article:
>
>http://www.darkroom.com/MiscDocs/bokeh.pdf
>
>I believe it differs from your conclusion.
>
> > -----Original Message-----
> >
> > Just as a general information point, lens "Bokeh" is a lens
> > design formula
> > property. It has nothing to do with the diaphragm type, shape, or
> > number of
> > blades.
> >
> > snip>
> >
> > Jim
From: "Austin Franklin" darkroom@ix.netcom.com>
To: hasselblad@kelvin.net>
Subject: RE: Aperture blades and Bokah (Bokeh)
Date: Fri, 7 Sep 2001
No doubt lense formula has a large part to do with bokeh, but I also believe
that aperture shape does too. Obviously, if you're full open, then more
lense formula than aperture shape 'fer sure!
Did you take a moment to read the paper?
> -----Original Message-----
> From: Jim Brick [mailto:jim_brick@agilent.com]
> Sent: Friday, September 07, 2001 9:19 PM
> To: hasselblad@kelvin.net; hasselblad@kelvin.net
> Subject: RE: Aperture blades and Bokah (Bokeh)
>
>
> I read all of the Bokeh articles in "Photo Techniques" a few
> years ago and
> they, if I remember correctly, discussed the different types of Bokeh as
> well as the root cause of these Bokeh. It was my impression from reading
> those articles and talking to Erwin that lens formula has more impact on
> Bokeh than any mechanical external device. The 35/1.4 ASPH has
> much harsher
> and not as nice Bokeh as does the older non ASPH versions of the
> same lens.
> Likewise the old Summicron formula have better Bokeh than the latest
> Summicrons. And the diaphragm is not that much different, if
> different at all.
>
> Jim
>
> Austin Franklin wrote:
> >You might want to read this article:
> >
> >http://www.darkroom.com/MiscDocs/bokeh.pdf
> >
> >I believe it differs from your conclusion.
> >
> > > -----Original Message-----
> > >
> > > Just as a general information point, lens "Bokeh" is a lens
> > > design formula
> > > property. It has nothing to do with the diaphragm type, shape, or
> > > number of
> > > blades.
> > >
> > > snip>
> > >
> > > Jim
From: "Q.G. de Bakker" qnu@worldonline.nl>
To: hasselblad@kelvin.net>
Subject: Re: Aperture blades and Bokah (Bokeh)
Date: Sat, 8 Sep 2001
Austin Franklin wrote:
> No doubt lense formula has a large part to do with bokeh, but I also
believe
> that aperture shape does too. Obviously, if you're full open, then more
> lense formula than aperture shape 'fer sure!
Why? A full open aperture (usually. The 250 mm Sonnar does close the
aperture ever so slightly even at its largest f/5.6 opening. Perhaps other
lenses do tha same.) is circular. That's a shape too, isn't it? ;-)
Date: Tue, 18 Sep 2001
To: rollei@mejac.palo-alto.ca.us
From: Richard Knoppow dickburk@ix.netcom.com>
Subject: Re: [Rollei] bokeh
you wrote:
>Now, I hope this doesn't start a flame war as it used to do on the LUG - but
>I am REALLY enjoying the out of focus areas of my xenotar when used at wider
>appetures. It is inspiring me to doa whole sweries of stuff wide open. Do
>all 'flex lenses have this characteristic? I notice that there are 5 blades
>in the xenotar, does the planar have more?
>
>Julian
>-----------------------------------
>Julian Thomas
>Bruc 168-6-1
>08037 Barcelona
>
>http://www.borderless-photos.de/jthomas/jthomas-01.html
The iris is part of the shutter. Since both Planar and Xenotar Rollei's
use the same shutter they should have the same type of iris. The same
five-bladed iris is found on other lenses mounted in Synchro-Compur
shutters, like the Schneider Super Angulons.
The shape of the iris opening does affact the shape of blur spots in the
image. The Japanese use the word bokeh to describe the character of the out
of focus areas of the image. One can argue interminably about this.
The older version of the Synchro-Compur, used in the Rollei MX and
Rolleicord IV, has a ten blade iris and a nearly perfectly round hole. EVS
cameras use a different shutter and may have the five blade iris.
I think the use of fewer iris blades may have to do with a different
method of driving them. You will notice that the five blade iris is found
on EVS cameras and that the f/stop scale is linear. The older shutters have
a non-linear scale, compressed at the small stop end. For EVS the linear
scale is necessary. I suspect that the diameter of the iris mechanism may
get too large when more blades are used.
The lenses with the closest to circular iris openings seem to be process
lenses. Here, the shape was important when using the lens for half-tone
work. However, very often Waterhouse stops were used with special shapes
(square or eliptical were common) because of advantages of the special
shapes. Some process lenses have twenty blade iris diaphragms.
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com
From: "David Kieltyka" daverk@msn.com>
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Nikon - primes that deliver creamy bokeh
Date: Sun, 02 Dec 2001
Robert Alvarez ralveraz@hotmail.com> wrote:
> I'm in the works of purchasing a nikon set.
> the primes I was planning to pick up was the 24mm 2.8, 50mm,
> and the 85mm 1.8. If price wasn't a factor, I would go with the
> 105 dc.
>
> How's the boken on these 3 lenses. Afaik, these three are all
> great performers in regards to sharpness but hows the bokeh?
> Haven't shot in a LOng while and I used to carry a M3 back in
> college. Can't afford a Leica these days!
The only Nikkors I'm familiar with are the early ones, from the 1950s and
'60s. Many of these lenses, notably the 50, 85, 105 and 135mm, derive from
classic Zeiss designs and give an out-of-focus look consistent with this. I
wouldn't say the bokeh is creamy. It's not harsh either but it is edgier
than you'll get with the most bokeh-friendly Pentax or Leitz lenses. I have
a Nikon F outfit-24 f/2.8, 50 f/1.4, 105 f/2.5 and 200 f/4-that I use
exclusively with fast b&w film. (Usually Ilford HP5+ developed in Agfa
Rodinal.) For this use the OOF quality of the Nikkors is just the thing.
-Dave-
From: Anthony Polson acpolson@hotmail.com>
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Nikon - primes that deliver creamy bokeh
Date: Mon, 03 Dec 2001
Robert Alvarez ralveraz@hotmail.com> wrote:
> I'm in the works of purchasing a nikon set.
> the primes I was planning to pick up was the 24mm 2.8, 50mm, and the
> 85mm 1.8. If price wasn't a factor, I would go with the 105 dc.
>
> How's the boken on these 3 lenses. Afaik, these three are all great
> performers in regards to sharpness but hows the bokeh? Haven't shot in
> a LOng while and I used to carry a M3 back in college. Can't afford a
> Leica these days!
Hi Robert,
It all depends on whether you will accept recommendations for AF
Nikkors, MF (AIS) Nikkors or a mixture of both.
First the wide angle lens. Bokeh is not so critical with wide angles as
they offer too much depth of field even wide open. Possibly the one
exception in the Nikkor range is the 35mm f/1.4 AIS which has good
bokeh. The 24mm f/2.8 AF is a superb optic but given the short focal
length and not-so-wide maximum aperture, bokeh is not really an issue.
There are no current 50mm Nikkors with good bokeh. You might like to
take a look at the new 45mm f/2.8 AI-P which is a highly optimised
Tessar design, and is reputed to have excellent bokeh. I can't confirm
that, never having used one.
The 85mm f/1.8 AF has very good bokeh. This is my favourite lens of all
and I always carry it with me on assignment. It's a good portrait lens.
The 85mm f/1.4 (AIS or AF) is a super performer with excellent bokeh,
but it is just a little too sharp for me. It's also heavy.
The 105mm f/2.5 AIS is a *sublime portrait lens with sublime bokeh*.
I think very highly of this lens, especially as it's still in Nikon's
catalog and can be purchased for a very reasonable price.
Then there are the 105mm and 135mm f/2 DC AF lenses. I have the 135mm
and love it. The variable bokeh feature is sensational, but even at its
best the lens is not superior to the 105mm f/2.5 AIS. The bokeh may be
variable, but it never surpasses that of the 105mm AIS version IMO.
I also have the 180mm f/2.8 AF-N which is a very fine optic with superb
bokeh.
It's difficult to choose one favourite but mine would probably be the
75-150mm f/3.5 (constant) Nikon Series E lens. It has the best bokeh of
any of the lenses I mentioned above, plus it's a zoom! This is a very
fine performer. It's so good that the 'Series E' tag is irrelevant.
These are very personal opinions, so don't rely on them 100% to inform
your buying decisions. Instead, try before you buy.
Good luck!
[I wish someone would post something similar for Canon EF lenses!]
--
Best regards,
Anthony Polson
From: Zeljko Kardum kardum@zagreb.cc>
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Nikon - primes that deliver creamy bokeh
Date: Thu, 06 Dec 2001
The only one I could suggest is 50/2 AI
Absolutely beautiful
People overlook this lens cause it's not high speed and it's too cheap
to be considered seriously.
--
Kardum
http://www.kardum.com/
Robert Alvarez wrote:
>
> I'm in the works of purchasing a nikon set.
> the primes I was planning to pick up was the 24mm 2.8, 50mm, and the
> 85mm 1.8. If price wasn't a factor, I would go with the 105 dc.
>
> How's the boken on these 3 lenses. Afaik, these three are all great
> performers in regards to sharpness but hows the bokeh? Haven't shot in
> a LOng while and I used to carry a M3 back in college. Can't afford a
> Leica these days!
--
Kardum
http://www.kardum.com/
From: Anthony Polson acpolson@hotmail.com>
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Nikon - primes that deliver creamy bokeh
Date: Thu, 06 Dec 2001
brianc1959@aol.com (brian) wrote:
> Hi Tony:
> The only place I disagree with you here is on the 85mm/1.4 AIS. I
> find this lens has very pronounced sharp edges on background
> defocussed highlights, which most people would call bad bokeh.
Brian,
As with so many of your opinions, this one must surely fly in the face
of the views of the vast majority of photographers who use this lens.
Sales of this heavy, expensive and somewhat intimidating lens have
always been higher than Nikon could reasonably have expected. Indeed,
it was the ongoing very high demand for the AIS version that caused
Nikon to introduce the recent AF-D version which, although only slightly
changed, is better than the AIS version.
I have tried several samples of both, including buying one AIS version
on eBay and returning it to the USA for a refund. Our testing program
included no less than *five* examples of this lens, 2 of which were AIS
and the others AF-D.
They were all very fine performers. The bokeh did not differ between
the AIS and AF-D versions, but the contrast of the AF-D was slightly
higher, giving greater apparent sharpness.
I don't use this lens because it is, in my opinion, far too sharp for
portraiture. It resolves every line and wrinkle, and needs a far more
powerful soft focus filter than I am prepared to use. I much prefer the
85mm f/1.8 AF(-D).
To come back to the bokeh, I restate that this is one of Nikon's very
best lenses for all-round performance *including* bokeh. You will not
find many people disagreeing who have used this lens for serious work.
Maybe you got a bad sample. Whatever, this is yet another entry in the
catalog of lenses where your opinions are diametrically opposite to
those of the bulk of their users.
You must be an extremely unfortunate person to have had consistently so
very much bad luck.
--
Best regards,
Anthony Polson
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Design criteria for excellent bokeh
Date: 11 Dec 2001
Of course, "diffraction limited lens with a fairly large aperture" was
exactly what I implied. Glad you took it on yourself to clarify.
Bokeh, like zoom lenses, is rarely mentioned in the book literature.
Even in the patent literature you hardly find reference to it.
Actually, there are a number of people who post on this NG (or at
least used to) who have a better working knowledge of bokeh than most
lens designers. Which is one of the reasons I bother wading through
some of the garbage that gets posted here. And I've never heard
anyone describe the aberration characteristics of a lens with good
bokeh, although I've heard many here express a curiosity about what
those characteristics are. Which is the reason I posted this thread.
What I stated is not a quote from someone else, but rather a pretty
straightforward thing to deduce, Bruce. Bokeh does exist, it is an
important characteristic of a lens, and it can be fully understood
using simple ray tracing. The bokeh of a lens can be accurately
modeled on a computer by simply defocusing a lens and plotting the
spot diagram. This spot diagram is a very close approximation to a
defocussed point image, and any concentrations of light are easy to
see. Its easy to introduce aberrations experimentally by using a
perfect lens and placing an aspheric plate at the stop. By varying
the aspheric coefficients you can vary the amount and type of
aberration, and the effect on bokeh can be observed directly. I've
also examined a number of designs in the patent literature of lenses
that I actually own. I can then compare a computer simulation with an
actual lens.
Brian
Bruce Murphy pack-news@rattus.net> wrote
> brianc1959@aol.com (brian) writes:
>
> snippy
>
> > If you prefer neutral bokeh, where the defocussed highlights look
> > similar on either side of focus and have a nearly uniform intensity
> > profile, then all you have to do is design a diffraction-limited (or
> > nearly diffraction-limited) lens. Cine lenses often get the neutral
> > bokeh treatment because cost is of little concern.
>
> And what you failed to note here is a "diffraction limited lens with a
> fairly large aperture". We're sure you're very proud of all those
> optical design books you own (or borrowed), but we've heard enough
> quotes now.
>
>
From russian camera mailing list:
Date: Tue, 01 Jan 2002
From: "yupiter3" ccm952@bellsouth.net
Subject: Jupiter 3 Bokeh versus Leica & Canon
This is an interesting link I stumbled upon.. It shows out of focus
qualities for a russian Jupiter 3 50mm F1.5 ; Leica Summarit
50mm/F1.5; and a Canon 50mm/F1.2 ....
http://www.comworks.gr.jp/~taka/hobby/camera/Lens/Boke/
Copyright (c) 1988-2001 by Takashi Sugioka. All rights reserved.
e-mail: taka@takanet.com
regards; Philip
-----
Date: Tue, 01 Jan 2002
From: "wanatunda" wanatunda@yahoo.com>
Subject: Re: Jupiter 3 Bokeh versus Leica & Canon
Hi Philip,
Thanks for the link. I also found this one of interest
http://www.comworks.gr.jp/~taka/hobby/camera/Lens/LensTest/
It contains the test of the Jupiter 8,Industar 22, 26, 50, 61,
compared to the likes of Leica Elmar, Summarit, Summar etc.
I am feeling a little better about the Helios 103 I took apart to
clean the oil from the blades and the inner elements. Got it back
together and it shoots better than the day I got it. In all
fairness, aside from a 90mm 3.5 for my Koni Omega, (yes it goes on a
Rapid 100), it is the sharpest lens I own. Here's the punchline...It
came on a camera that cost me 39.00 plus 15.00 in shipping from the
Ukraine, and is probably a bad example of the breed. Many tiny
scratches.What an incredible bargain!!!
thanks again
Sincerely
Felix
From leica mailing list:
Date: Sat, 05 Jan 2002
From: bachchaconne@my-deja.com
Subject: [Leica] Bokeh ain't no Leica myth - says Minolta and Nikon
See
http://www.munitions.com/jgreely/stf135/page0.html
http://www.nikon.co.jp/main/eng/photo_world/kumon/06e.htm
Bokeh_IS_the raison de etre of these lenses... and how I wish I had
one of them, especially the STF. :)
Andrew
From leica mailing list:
Date: Sat, 05 Jan 2002
From: bachchaconne@my-deja.com
Subject: [Leica] Bokeh ain't no Leica myth - says Nikon
Oops, should have included this too:
http://www.nikon-image.com/eng/LensGuide/opt_tech2.html#AFDC
Andrew
From leica mailing list:
Date: Wed, 2 Jan 2002
From: "Austin Franklin" darkroom@ix.netcom.com
Subject: RE: [Leica] Bokeh - proven myth ?
> Austin Franklin wrote:
>
> >It's not existentialism, it's purely physics, and not that difficult to
> >understand, or see.
> >
> >http://www.darkroom.com/MiscDocs/bokeh.pdf
> >
> What an excellent article! Thanks for the link - I feel like I
> understand it a little better now, though I much prefer to just look at
> the results of my lenses and decide which has a more pleasing bokeh.
>
> - marc
Marc,
My pleasure! Always glad to provide substance over speculation ;-)
Regards and Happy New Year!
Austin
From leica mailing list:
Date: Wed, 2 Jan 2002
From: "Austin Franklin" darkroom@ix.netcom.com
Subject: RE: [Leica] Bokeh - Leica myth.
Dante,
> It is a myth that "bokeh" is an inherent or intentionally-created
> characteristic of any Leica lens.
Why? Do you have proof of this? Did you read this:
http://www.darkroom.com/MiscDocs/bokeh.pdf
It clearly shows that one CAN design bokeh "into" a lense. How do you
know what characteristics of a design are intentional and not intentional?
Just because something is inherent, doesn't mean it wasn't intentional.
> What we call bokeh is a complex of aberrations in out of focus areas. As
> Erwin Puts is quick to point out, for about 75 years, Leica has
> attempted to
> design all aberrations out of their lenses. As they become more and more
> successful at eliminating them, the bokeh gets worse and worse.
I don't agree with that. How come my Zeiss 110/2 has the best bokeh of
any lense I have ever seen, and it's a very modern lense? As well as my
85/1.4 Zeiss for my Contax? This may also be true with the Leica lenses,
it's just that I don't have any of the latest designs, like the 90/2 to
see if the bokeh is "worse", but it sure isn't "worse" on my 50/1.4 and my
75/1.4.
Austin
From leica mailing list:
Date: Wed, 02 Jan 2002
From: "dante@umich.edu" dante@umich.edu
Subject: Re: [Leica] Bokeh - Leica myth.
I think we are talking at cross-purposes. My comment was that Leica AG
(and Leitz before it) is purposefully vanquishing aberrations, and in
doing so is designing bokeh "out" of its lenses. As you and I are aware
(and yes, I read that article several times over the past year), other
companies (Nikon, Konica, and Zeiss) are indeed designing it back in. It
was a statement on Leica's core values in lens design, not on the ability
of someone to design for (or against) bokeh.
.....
From leica mailing list:
Date: Wed, 2 Jan 2002
From: gb@murphy.bofh.ms (Georg Bauer)
Subject: Re: [Leica] Re: Bokeh - proven myth ?
Henry Ting henryting10@yahoo.com writes:
> physics". Where I'm standing, existentialism is what
> exist, proven and controlled after my experiment. Not
> at all quacky, don't you think ?
Yeah. You sample two lenses and conclude your utter wisdom. Laughable.
Sorry, but to really comprehend the complex thematics of optics, you
for example should try out a Hektor with a 18-blade-diaphragm against
some of those el-cheapo 4 or 5-blade-diaphragm lenses. _Then_ you will
see that much more than just the focal-length is important to
out-of-focus areas. The complete lense-design comes into play, as the
bending of the light falling onto the film plane is what makes
different out-of-focus rendering.
It's not a leica myth, it's actually not a myth at all, it's just plain
and stupid optics. Oh, and it is not connected to Leica at all, it's
just that Leica-photog's tend to notice it more, since many of them
shoot with full opened or almost full opened aperture.
There is nothing funny about seeing no big difference between high-end
Nikon lenses and Leica lenses. It's not as if Nikon produces just
garbage ...
Oh, another nice subject for testing would be to run a zoom lense
against a prime lense. Should give you additional input for drawing
conclusions.
bye, Georg
From leica mailing list:
Date: Wed, 02 Jan 2002
From: Steven Alexander alexpix@worldnet.att.net
Subject: Re: [Leica] Bokeh - proven myth ?
>
> Quite simply I have never related to the effect, as it's put forward by some
> very good shooters here. I'm always looking at the content factor / moment
> with never a thought about the effect of bohek, as bokeh happens just like
> breathing, in particular when shooting primarily wide open.
>
> Sure I use foreground to frame and do that kind of thing any number of
> times, but I use it as a framing factor to enhance the scene and not because
> of the bokeh factor. I also, without thought, know if I'm working with a 180
> wide open and shooting people at close range, the bkgrd will be a mush of
> colour or greys in B&W
> The question is, when you were shooting this photo or similar, do you have
> the thought in mind of how the bokeh factor will look for the lens you're
> using? As in a specific thought, "the bokeh will look great for this xyz
> lens" ? And if all of a sudden you think, "Oops, I better change to the XXX
> lens for a better bokeh."
>
> Maybe I'm wrong on this whole bokeh question simply because I can't get past
> the thought that while I'm shooting an assignment that I'd be thinking about
> the bokeh effect rather than concentrating on the precise moment for the
> "perfect picture."
>
> Or am I seriously missing something? Over to you my friend.
My question after 4 decades of professional shooting 2 of them in Washington
D.C., shooting side by side with many of those folks mentioned by Sal, is
there really any discernible difference between any 180mm lens wide open
focused at 7 feet rendering of the OOF background? This question applies to
any focal length used in a like manner.
I too, as Ted, Sal and other pros am always open to learn from others but
in my experience I see no difference in this characteristic of a Leica
optic and any other top quality optic. And sure would not decide on this
idea how, from where, or at what point to focus any given picture. There
are other differences in the optics that led to my complete switch to
Leica optics. An agency that represented my work had an entrance that
opened to the editing space below and certain images at that distance
appeared different, more vibrant, cleaner color, and something different.
It wasn't film, lab or anything else except the optics( I discovered some
of these images were mine created with my M equipment so after much angst
I parted wonderful Nikon stuff for Leica R stuff. This change had nothing
to do with OOF background plain of (out of) focus.
[Ed. note: Mr. Kramer is a past lens tester for Camera 35 and Modern Photography etc.
and author of sundry columns (View from Kramer) and resources....]
From: artkramr@aol.com (ArtKramr)
Newsgroups: rec.photo.equipment.35mm
Date: 10 Mar 2002
Subject: Re: 3D quality of Nikon lenses
>If you by top quality mean lenses with 3D qualities you're right. Most
>of even the best lenses won't give you this effect. Particularly, most
>macro lenses will not show this effect.
>Again, it demand fine tuning of certain optical abberations. I doubt
>you will find it in eg. any Canon lens which generally yield totally
>flat looking images.
>I guess this discussion is like discussing fine wines; some just don't
>get the finer things.
The Hugo Meyer Plasmat was designed specifically to produce a "roundness" or 3D
effect.
Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer
Postscript:
After the Hugo Meyer produced the Plasmat Voightlander produced the Heliar
which also was designed to produce a 3d or "round" effect.
Post-postscript:
The Leitz Thambar was said to have been designed to produce that same
"roundness".
Date: Wed, 25 Apr 2001
From: Tony Polson tony.polson@btinternet.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: This is why I own a Leica
ss@randomc.com (Steve) wrote:
> >tony.polson@btinternet.com wrote:
> >ss@randomc.com (Steve) wrote:
>
> >> The Nikkor 50mm 1.8 isn't a consumer grade lens - I'd put it up against
> >> anything out there for image quality.
>
> >Hmmm.
>
> >It's sharp and has good contrast and resistance to flare.
> >But its bokeh is not the best.
>
> >I wonder whether the rumoured new 50mm f/1.8 AF-D has been given the new
> >rounded iris diaphragm blades that Nikon seem to fit to all their new
> >optics? That would *help* the bokeh, although it might not *rescue* it.
>
> Funny thing Tony, I just bought an older AF 85mm 1.8 and it has 9 blades
> instead of 7 like the newer one. I'm not sure how rounded it is....or how
> much this helps Bokeh....
9 blades is better. Rounded blades are the best. Nikon believe that
one of the biggest and easiest improvements they can make to lenses'
bokeh is to provide a more rounded aperture in the iris diaphragm. In
the shot we've discussed that was taken with the Noctilux f/1.0,
probably the most obtrusive aspect of the out of focus elements of the
picture was the flare; the image of the aperture in the iris diaphragm
became the hexagonal (IIRC) highlights that were so clearly visible -
and unpleasant - proving that the lens has six iris diaphragm blades.
By using a greater number of diaphragm blades the aperture (opening) in
the iris diaphragm becomes nearer to a circle. But an even better
effect can be achieved by using diaphragm blades whose edge (the one
that forms part of the opening or aperture) is curved.
The curvature varies along the edge of the blade. For the larger
openings the curvature matches the diameter of the effective maximum
aperture of the lens. For example, in a 50mm f/2 lens the effective
aperture would be about 25mm, being the focal length f (50mm in this
case) divided by 2. In a 90mm f/4 it would be about 90mm divided by 4,
giving 22.5mm.
As the blades turn to give the smaller apertures the curvature of the
blades becomes sharper. The idea of this is to present an aperture that
is as close as possible to a perfect circle at every f stop.
Nikon have put a lot of work into getting the curvature of the blades
exactly right, and it seems to have worked. For example, the 85mm f/1.4
AF-D Nikkor has the new curved blades whereas the most recent batch of
the optically near-identical AIS version had straight edged blades. The
result (according to Nikon) is an improvement in the AF-D lens when
compared to the already good bokeh of the AIS lens.
What concerns me a little is that Nikon may believe that changing the
iris diaphragm blades to curved is enough to transform the bokeh of a
lens. I don't believe that's true for all lenses.
As Nikon have shown great reluctance to invest in developing their well
established fixed focal length lenses I expect we will have to be
content with their bokeh as it is, or with the improvement that comes
from changing the iris diaphragm blades - but no more. I think there
must be a lot more to bokeh than the shape of the diaphragm blades but
curved blades are probably a good start.
Nikon must have learnt a lot about how optical design affects bokeh
through the design of the DC lenses, which allow the photographer to
vary the bokeh 'on the fly'. This is achieved by changing the
aberration characteristics of the lens with a control not unlike a zoom
ring. Alas the expense and rarity of these lenses means I haven't had
the chance to try one.
I hope this is useful. I wish I knew more about the subject.
Refraction, diffraction, dispersion, sharpness, contrast, spherical and
chromatic aberrations are all things I can understand, but I'm only
beginning to learn about bokeh.
No doubt someone who knows a lot more than I do will be kind enough to
correct any errors in the above.
Best regards,
--
Tony Polson
Date: Wed, 25 Apr 2001
To: rmonagha@post.smu.edu
Newsgroups: rec.photo.equipment.35mm
Subject: Re: This is why I own a Leica
there are lots of inferential reasons to suspect that lens aberration
control rather than diaphragm shape, size, number of blades etc. is really
the major factor in bokeh; when shooting wide open, after all, you often
get little or no stopping down, and yet this is where many such lenses are
used (e.g. Leica) which are famed for their bokeh ;-) some great bokeh
lenses have only 2 blades (minox); clearly, blade count or shape is only a
modest factor or easily countered by many wide open good bokeh lenses?
my suspicion is that blade count idea (more blades = better bokeh) arises
as the older lenses which have more uncorrected or overcorrected spherical
aberration, and hence better Bokeh by some tastes, also tend to have been
made in an era when lenses had many more blades (up to 13 or more) than in
today's more $ conscious times where more blades cost a lot more and so
are dropped (part of the reason lenses are cheaper in real $ terms today).
grins bobm
From: Tony Polson t.p@nospam.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Leica M lens tests URL followup was Re: Leica...Is It Worth It?
Date: Mon, 22 Apr 2002
JETman jetassoc@worldnet.att.net wrote:
>Many years ago before "bokeh" was a catch word, I noticed something
>startling different with a new lens that I had bought to go with my M2
>outfit. It was a 125MM Hektor made in Canada which at the time was
>fitted to a Visoflex II.
>
>The startling feature, the way that the out-of-focus portion of close up
>photography appeared. I was doing a catalogue for a nursery and had
>shot several hundred Kodachromes of varieties of Iris. I had never
>noticed an effect such as this but now I know..... It was great bokeh!!!
>
>Obviously, such has its roots in lens quality and design. Both are
>requirements and Leica has the edge because strict manufacturing
>controls ensure that all design objectives are met. Mass manufacturere
>do not have this option.
>
>Is it costly? Yes!
>
>Is it worth it?? You bet!!!
There is no need to buy expensive Leica glass to get good bokeh. Many
lenses from the more widely-sold brands also have good bokeh *and*
they cost far less.
It's also true that the most recent Leica designs have been developed
for greater apparent sharpness and this has been somewhat at the
expense of bokeh. The ASPH lenses for the M Series simply do not
offer the desirable "look" that was implicit in previous designs.
Leica lenses have great strengths, however baseless and over-the-top
statements such as yours and Meryl's do the brand no good whatsoever.
Date: Mon, 22 Apr 2002
From: "Brian" patience@e-mailanywhere.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Leica M lens tests URL followup was Re: Leica...Is It Worth It?
If I understand you correctly, "mass manufacture[d]" lenses cannot compete
with the "great bokeh" of the Leica lenses, because less expensive lenses
are manufactured such that "all design objectives [cannot be] met."
Do you mean that no other lenses can produce bokeh as pleasing as these
examples?
APO-Telyt 180 f3.4 bokeh sample
http://www.photo.net/photodb/image-display?photo_id=465198&size=lg
Summicron 35 2/0 (last pre-ASPH) wide open bokeh sample
http://www.photo.net/photodb/image-display?photo_id=712480&size=lg
Actually, I'd guess that many inexpensive lenses could produce out of focus
areas _at least_ as pleasing as the little bright-edged rings in those
posted photos.
Of course, stopped down just a bit, the Summicron may produce really
beautiful out-of-focus areas, but wide open--at least as seen here--it
looks. . . unexceptional. The APO-Telyt may have been manufactured to reach
"all design objectives", but perhaps good bokeh wasn't one of the
objectives.
Bokeh, is a bit subjective, but I have lenses which certainly seem to yield
more pleasing out of focus areas than these photographs
From: ski2photo@netscape.net (Jerry L.)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: defocusing lenses?
Date: 24 Apr 2002
For a sample of how the lenses work,
please see
http://www.photo.net/photodb/photo?photo_id=563041
...as published on page 16 in the March 2002 issue of Shutterbug magazine.
...
> I think he is referring to the Nikon 135 f/2.0 DC AF. There is also a 105mm
> version. The lens has a defocus control lever on the lens to blur the
> background on a portrait. You focus after blurring the background. Some
> reviews in photo.net give it a not so good rating but I have to say that I
> absolutely love the lens. It's probably my favorite. Makes an amateur like
> me look like a pro. Sorry, can't think of any websites with images using
Snip'd
> > effect can be quite the same (no first-hand knowledge though).
> >
> > Sorry, don't know any relevant sites.
> > --
> > David Littlewood
From: Tony a_p@nospam.tv
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Old Pentax Spotmatic users out there?
Date: Mon, 06 May 2002
Ron Todd rltodd@ix.netcom.com wrote:
>The only function of the super multi coating is to reduce flare. I have
>single coated Super Takumars and I assure you they perform excellently
>with color film.
The side-effect of good coating that's equally or more important than
flare reduction is that it obtains increased contrast. Increased
contrast means increased apparent sharpness. The contrast reduction
caused by less-than-optimal coating occurs all the time, not just when
flare is visible in the viewfinder or on the film.
The importance of this is that the lens designer need not over-correct
the lens's spherical aberration in order to optimise sharpness.
That's why lenses with very good AR coatings can obtain excellent
sharpness while retaining the wonderful out of focus effects that
characterise the truly *great* optics.
The difference between the Takumars and Super-Takumars was hugely
significant. The Super-Takumars were known to be sharper even if they
were of the identical optical design to their predecessors, all
because of the improved coatings, including some multi-coating.
The difference between the Super-Takumars and the Super-Multi-Coated
M42 Takumars was less significant. All the glass-to-air surfaces were
multi-coated but the improvement was relatively small. Yet the SMC
Takumars were among the very best lenses of their time, giving away
surprisingly little to Leica glass.
My own tests of M42 Super-Takumar and SMC-Takumar lenses and some of
their K- and M-mount successors seem to indicate that optical
standards dropped at Pentax. In particular, the superb contrast seems
to have been reduced. Sharpness appears to have been maintained more
by over-correction of aberrations than good coating and at the expense
of the more desirable qualities of a lens.
>BTW, the turning yellow with age problem. It wasn't the coating, it is
>the glass. Has something to do with the rare earth glass they were
>using at the time. I have one, it gives a nice warm effect on color
>slides.
None of my M42 Super-Takumar and SMC-Takumar lenses seem to have this
problem - yet. But I have a 20mm f/2.8 Flektogon (made in Jena) which
has a noticeable yellow cast. I use it only with black and white
film, when it offers a similar effect to a pale yellow filter. {g}
It has lost none of its sharpness or resistance to flare; another
example of the difference that good AR coatings can make.
From rollei mailing list:
From rollei mailing list:
Date: Tue, 27 Mar 2001
From: Richard Knoppow dickburk@ix.netcom.com
Subject: Re: [Rollei] bokeh consternation
you wrote:
>Without causing the dismay of those who have beat this puppy to death
>already, can anyone say in few words which of the TLR Rolleis render the
>better bokeh? Notwithstanding good bokeh is in the eye of the beholder, but
>in general terms, does the which of the 2.8 or which of the 3.5 gives the
>better out-of-focus image?
>
>thanks,
>
>John
Bokeh is one of those bit of esoterica I find fascinating. I am not sure
what pleasing bokeh is although it must certainly not be the sort of thing
where you see multiple images of an odd shaped diaphragm. It would seem
that round diaphragms have a leg up as far as bokeh is concerned but likely
the most significant contributor is the rather complicated things that
happen to out of focus aberrations.
We tend to think of the projected image as a two dimensional thing
existing on a plane at the film. In fact a lens projects a three
dimensional image, at least of a three dimensional world. All is in focus
someplace. There really are longitudinal aberrations affecting the way a
point is imaged in the long way as well as the wide way. A lens can have
good correction for lateral aberrations and still not be quite right for
longitudinal ones. Undoubtedly this has something to do with bokeh.
If it can be seen it can be measured, but what to measure? Maybe
defocused energy distribution, only a suggestion.
Its well known that aberrated lenses do not follow the rules for depth of
field, which is a sort of manifestation of bokeh. Soft focus lenses are
aberrated deliberately. Some seem more pleasing than others. Definitely the
blur pattern of an Imagon is different from a lens like a Wollensak Verito,
which is an achromatic doublet with plenty of uncorrected spherical. These
are different yet from a deliberately de-corrected (to coin a term) Cooke
Triplet. This also has lots of uncorrected spherical, but it looks different.
BTW, Cooke is considering making short runs of Cooke Triplet soft focus
lenses. Any takers? They are trying to determine if there is a market.
I am fresh back from work having spent the last bit in a bunker full of
5KW microwave transmitters all busily sending cable television programs up
to a satellite where they should be shredded and trashed but instead get
turned around to litter the countryside. Lots of big blowers, sounds like
the engine room of a ship or maybe a cheap seat on the outside of the
Concorde (is it still grounded?). I think I should sign off now and sleep.
Heigh-ho.
----
Richard Knoppow
Los Angeles,Ca.
dickburk@ix.netcom.com
From: bachchaconne@my-deja.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Superspeed lenses and "window effect".
Date: Thu, 09 May 2002
>Andrew:
>
>Oops, the other message got sent before I could type it - sorry about that! I
>believe I might have been to that URL before. Also there is an example of this
>bad background bokeh w/ good foreground bokeh in the Malaysian? site that
>describes Nikon's lenses/etc. which goes by the title of "A thousand and one
>nights" or something like that. There is a shot of the 50mm f/2 focused close
>that shows a nice creamy foreground and a not so nice background. Another URL
>(different site) shows the effects of the Nikon 135mm? DC Nikkor w/ spherical
>aberration corrected for both over-correction (nice foreground bokeh) and
>under-correction (nice background bokeh. I wish I could remember their URLs but
>I can't.
Lewis, here you go:
http://www.nikon.co.jp/main/eng/photo_world/kumon/06e.htm
http://www.nikon.co.jp/main/eng/society/nikkor/n02_e.htm
Note the effect of the hexagonal aperture on very bright highlights.
My cheapo Yashica 28mm has exactly the same effect. Likewise I wonder
why Zeiss keep making so many lenses (e.g. both 50mm Planars,
85/100/135mm Sonnars, 45mm Planar, etc) with hexagonal apertures.
Leica also has lots of lenses with even-numbered blades.
> I shoot w/ Zeiss lenses so I get perfect bokeh both fore and aft all
>the time, particularly w/ my 28mm f/2.8 Distagon used at or near wide open.
You must be one lucky guy, or your lens is extremely well corrected
for spherical aberration and/or coma. I own 3 lenses by Zeiss: 38mm
Sonnar, 50mm Planar and 85mm Sonnar. Under different conditions, the
same lens can have good, okay or bad bokeh. In my experience, the
type of background (e.g. tree branches, highlights in foliage, wire
fences are difficult to deal with), the location of the OOF highlight
in the frame, how far away and how bright and big they are, the
focused distance, the aperture used...all of these contribute to the
resulting bokeh.
Andrew
From: bachchaconne@my-deja.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Superspeed lenses and "window effect".
Date: Sun, 12 May 2002
Obviously you haven't read through the page on the 2nd link:
"For an AI lens, this one (2/50) is unusual in having a six-bladed
diaphragm.
This produces a hexagonal blur image when stopped down, with the
possibility of producing night scenes where lights are surrounded by
six(6) rays when the aperture stop is stopped down.
Later Nikkor lenses were designed with an odd number of diaphragm
blades in order to eliminate these "rays" and the consequent loss of
resolution, but there are creative possibilities in exploiting this
effect for some scenes.
"((Example 2.)) is an illumination scene, shot with the aperture at
f/4 to eliminate flare.
This may not be clear on your monitor, but each individual light bulb
has six(6) rays coming from it, giving a vivid sense of the
illuminations."
Andrew
Paul van Walree info@vanwalree.com wrote:
>The bachchaconne@my-deja.com wrote:
>
>>Lewis, here you go:
>>http://www.nikon.co.jp/main/eng/photo_world/kumon/06e.htm
>>http://www.nikon.co.jp/main/eng/society/nikkor/n02_e.htm
>I wonder: why odd? A hexagonal aperture looks more circular to me than
>a pentagonal aperture. The more blades the better a circle can be
>approached, I just don't get the odd thing.
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Superspeed lenses and "window effect".
Date: 21 May 2002
bachchaconne@my-deja.com wrote
> >>diaphragm.
> >>This produces a hexagonal blur image when stopped down, with the
> >>possibility of producing night scenes where lights are surrounded by
> >>six(6) rays when the aperture stop is stopped down.
> >>Later Nikkor lenses were designed with an odd number of diaphragm
> >>blades in order to eliminate these "rays" and the consequent loss of
> >>resolution, but there are creative possibilities in exploiting this
> >>effect for some scenes.
>
> >The 6 rays emanating from each individual light bulb are clearly
> >visible for me. I just wonder why they fail to mention that a
> >pentagonal aperture leads to ten of such rays, and an aperture
> >with seven blades to fourteen (14) rays. So if 6 rays are
> >bothersome, how come 10 or 14 rays are less bothersome?
>
> Read again: they mean odd-number bladed iris *don't have* this "ray"
> problem. Supposedly the rays only emanate in pairs from "tips" of the
> polygon 180 degrees apart.
>
> Andrew
Andrew:
Regarding the diffraction rays, they emanate in a direction
perpendicular to the *flats* of the polygon, not the tips. If you
have an even-sided polygon this means that there are really two sets
of rays that overlap and reinforce each other. Thus, odd-sided
polygons produce twice as many rays as there are sides, while
even-sided polygons produce the same number of rays as there are
sides. Triangular and hexagonal aperture stops both produce 6 rays.
A pentagonal aperture will produce 10 rays.
Brian
From rollei mailing list:
Date: Fri, 31 May 2002
From: Siu Fai siufai@dds.nl
Subject: RE: [Rollei] Bokeh (Now in practice)
> Bokeh is japanese for the quality of the out of focus areas in a
> photograph.
This site shows some examples of differences in Bokeh:
http://www.pathcom.com/~vhchan/bokeh.html
The Rollei content: he has included the Rollei 50mm Planar and 35mm Tessar.
Siu Fai
From: rpn1@cornell.edu (Neuman - Ruether)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: The b-word: how is this achieved?
Date: Sat, 22 Jun 2002
handerle@klosterneuburg.net (Dr. Heinz Anderle) wrote:
>This question is not intended to burst into a flame-war.
>
>Although it is recommended not to use the b-word in this group, I
>would be interested how a smooth rendition of out-of-focus objects
>especially from normal and portrait lenses can be achieved.
>
>I have read that Leica and Minolta lenses are the best in this
>category, and that especially some Nikkors aren't anything but sharp
>with a strange double-contoured blur. Sometimes this really distracts
>from the main object (even when used at large apertures like f/2,8).
>From the lens drawings I have seen I can only tell that the lens
>designs for each focal length look quite similar (but I am not an
>expert). I have also read that optimizing a lens design for a high and
>contrasty resolution may deteriorate the b-word.
>
>Are there any trade-offs when a lens is de-optimized for a good
>unsharpness (e. g. more coma, more distortion, shallower depth of
>field?)
>
>How would other lens brands be rated (Zeiss, Pentax, Olympus, Canon) -
>and what about the independent lens makers?
>
>Thank you -
>
>Dr. Heinz Anderle
>living with Nikon non-b-word...
The poster above appears to have been unnecessarily rude...
Bokeh is quite real, but some of us prefer the "hard"
"bad" bokeh to the supposedly "good" bokeh. In the 500mm
f8 early Nikkor mirror, the high-contrast "edgy" out of
focus characteristic appears to usefully extend the
otherwise very shallow DOF one would expect from a lens
of this type. Same for "universal DOF" landscapes with
shorter lenses, where "good" bokeh lenses have more
trouble covering crisply the infinity-side of focus
compromised for maximum DOF. Also, it is possible to
take photos with "bad" bokeh lenses that would not be
as successful with "good" bokeh lenses (for examples
of these, see www.ferrario.com/ruether/sunplant1.html).
Other comments: some of us consider everything within
the frame to be "subject", as opposed to "subject and
background"; "good" bokeh is the result of undercorrected
spherical aberration, which does have some negative
consequences (some newer Nikkors are designed for this,
and a couple allow user-adjustment!); looking at lens
diagrams will give you no idea of how the lens will
perform; softer lenses often have a bit greater DOF,
in that it is harder to see the exact plane of focus;
if you are interested in Nikkors with "good" bokeh,
look for those designed for this, or get the AF
105 or 135mm FLs, which are also appropriate FLs
for much of portrait work...
(Ah, I managed to use the "b-word" about 8 times above,
so......;-)
David Ruether
rpn1@cornell.edu
http://www.ferrario.com/ruether
Hey, check out www.visitithaca.com too...!
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: The b-word: how is this achieved?
Date: 22 Jun 2002
Hi Heinz:
The key to good b- is to have slightly undercorrected spherical
aberration. In this case, rays from the edge of the pupil will focus
slightly ahead of the film plane.
The standard optimization routine built-in to most lens design
programs will tend to correct spherical aberration in a complex way,
with both under and over corrected regions. The reason for this is
that most programs attempt to zero the aberration at discrete points
in the pupil.
If you force the correction to be smooth and undercorrected, then what
normally happens is that the maximum amount of spherical aberration is
increased, and the contrast drops slightly. Coma, distortion, and
other aberrations aren't significantly affected.
Years ago I designed a small zoom lens that was nearly
diffraction-limited. Yet the bokeh turned out to be so bad that the
ring-shaped defocused highlights interfered with the autofocus system.
That problem was corrected with some clever firmware, but the whole
experience taught me a lesson.
Regarding other brands, some of the old Vivitar Series 1 lenses have
excellent b-. The 90mm f/2.5 macro has perhaps the best combination
of sharpness and b- of any lens that I know of. Olympus may also be
quite good, although I don't have personal experience with their
lenses. I did recently collaborate with a former Olympus designer,
and his designs had excellent correction for both b- and sharpness.
Brian
From rollei mailing list:
Date: Sun, 16 Jun 2002
From: "Joe B." joe-b@clara.co.uk
Subject: [Rollei] Rolleicord Vb: Xenars and boke
I got my test roll of slide film back from the Vb and although the
camera appears to be working well enough, the boke is not good at some
distances- there are circles with bright edges and there are double
lines and a jangly look to some backgrounds. I think that I will
return this one. While I would like a Rollei that is light in weight,
I also want it to have imaging characteristics that I like. But I'm
still somewhat confused. I have read somewhere recently about someone
else having this problem with the lens on a Vb. My daughter has a V
which has great out of focus rendition, which is part of the reason I
wanted to try a Rolleicord. It seems a little unlikely that Xenars
would be capable of varying this much, but I can't think of any other
explanation. If the results can be that much different, it must be
because the lenses DO vary that much. I thought this was going to be
easy. Maybe it isn't! But I am determined to find myself a nice
lightweight Rollei with good boke. I've heard good things about the
MX-EVS-2 and apparently it is not much heavier than a Rolleicord.
Maybe I'll try one of those next. (BTW I should probably clarify this-
I'm only talking about background boke, that is the kind that I am
concerned with).
It was quite disconcerting to read about the boke of the Tessar type
lenses and the Planar/Xenotar lenses, with comments mostly favouring the
former, and then observe how my 3.5F Planar has visibly better,
smooth, jangle-free boke compared to the Xenar on this Rolleicord. If
anyone can clarify any aspect of this any further that would be
helpful. Or just share some parallel or even contrasting
experiences... I feel myself to be in need of more data than
I've currently got.
Joe B.
From rollei mailing list:
Date: Sun, 16 Jun 2002
From: Eric Goldstein egoldste@earthlink.net
Subject: [Rollei] Re: Rolleicord Vb: Xenars and boke
"Joe B." wrote:
...(quotes above posting)
Joe -
Here's another possible explanation...
Around 1955 or so, F&H switched over to a new Compur shutter design, and the
iris got changed from a nice round complex multileaf design to a simpler 5
blade design. This definitely changed the character of the out of focus
areas; in my opinion for the worse...
The 'Cord V was manufactured from 54 - 57 (according to Evans) and so older
ones may very well have the complex iris... My 2.8 C was the last of the 80
mm lensed cameras to feature this iris and that is why I hold on to it...
The MX-EVS I just got for my nephew has the older iris/shutter; not sure
about the type II as they were made around 55 - 56...
I also suspect there is individual variation from lens to lens in the out of
focus areas as there certainly is in the in-focus areas... My 'Cord III from
1952 (Xenar) is terrific by all measures...
Eric Goldstein
From: "David J. Littleboy" davidjl@gol.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: at least i'm happy
Date: Tue, 9 Jul 2002
"Lassi Hippelainen" lahippel@ieee.org asked:
> >
> > Oh, I'm SO glad you didn't use The Word: BOKEH. Man, that starts
unending
> > threads. Heh. BOKEH! Did I mention BOKEH?
>
> It's like the bouquet in wine. Is bokeh really a Japanese word, or is it
> just bouquet in disguise?
It's a real Japanese word. B%\%1L#!!as on this page:
http://www.takanet.com/hobby/camera/Lens/Boke/
Or this page of folders at their widest f-stops:
http://www.takanet.com/hobby/camera/Lens/ForldingCamera/
Here's a folder with a 10-blade iris that can therefore be expected to have
good boke:
http://www.eva.hi-ho.ne.jp/yasuhiro-goto/Olympus6.html
(I saw one of these for US$200 or so the other day. Guess I should have
picked it up: the page says that the lens has good color reproduction, more
than adequate resolution, the focusing mechanism actually works, and it
provides lovely tonality in B&W and nice representation of detail.)
David J. Littleboy
Tokyo, Japan
From: fotocord fotocord@yahoo.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: at least i'm happy
Date: Tue, 09 Jul 2002
Godfrey DiGiorgi wrote:
>What do you need
> them all for? 2 or 3 is all I can imagine needing.
For different looks?
I have three different versions of 80mm's that all have different looks to
the pictures they produce. One is good for landscapes, the other works much
better for macro work (it's a 1:1 macro lens) while a third delivers a
smoother out of focus area and is softer wide open. With a blad you have
the option of a planar....
I have a 150mm f4.5 uncoated tessar in a focusing mount from the 1920's
that sure looks very different from the results of a more modern 180mm
sonnar. The 2X converter on the arsat 80mm looks different than either of
these.
Sometimes a 30mm can make a shot interesting while other times a 250 is
needed. Other times I don't want to carry a lot and take a 65mm and a 120.
Other times I'm shooting I take a 50, 80, 250 or maybe leave the 250 and
take some converters. It's nice to have these options IMHO.
And God forbid I hacked up one old biometar 80, removed all the original
glass and converted it to a single element lens
Maybe this is one reason I wasn't interested in a 'blad? Yes the lenses are
sharp and contrasty but if you want to experiment with a different look,
you have no other options other than the zeiss glass look. I know "That's
good enough for me" people always say, but I find some of these other
lenses make very interesting images that "better" glass wouldn't have
captured the way I wanted to.
I see them like a painters brushes, each can produce different results if I
know what they can do.
--
Stacey
From rangefinder mailing list:
Date: Thu, 11 Jul 2002
From: Bob Blakley blakley@us.ibm.com
Subject: RE: okeh dokeh what is bokeh?
Jeffery Smith wrote:
> As good an explanation as I've seen. The only thing I could add to it is
>
> that bokeh should not be confused with blurring (as causes by moving
> objects), and that the bokeh is increased with wider apertures.
>
> Here is an example of bokeh from a wide open 85mm lens at f/1.4
>
> http://www.jeffery-nola.com/PAW_22.html
Jeffery could have said (less modestly) that this is an example
of "pleasant bokeh".
Here's one I took which is an example of "unpleasant bokeh"
from a wide open Leica Summitar (circa 1950) 50mm lens
at f/2:
http://www.photo.net/photodb/photo?photo_id=861072
Note the weird rings of light etc... as compared to
Jeffery's very smooth out-of-focus areas.
From rangefinder mailing list:
Date: Thu, 11 Jul 2002
From: Bob Blakley blakley@us.ibm.com
Subject: RE: okeh dokeh what is bokeh?
> Gee.......I wonder if one could really classify any part of this
> photograph
> as 'bokeh'.
> I would class it as an out of focus photo, overall.
I should have explained that this is a blow-up of a small section
of the original slide, which you can see here:
http://www.photo.net/photodb/photo?photo_id=861062
As you can see, there are parts of the original which are in
focus :-)
From rangefinder mailing list:
Date: Thu, 11 Jul 2002
From: Rolohar@aol.com
Subject: Re: [RF List] okeh dokeh what is bokeh?
blakley@us.ibm.com writes:
http://www.photo.net/photodb/photo?photo_id=861062
Yes! Now that I have viewed the complete photograph, I will absolutely agree
with Blakley that this is not very good bokeh.
It resembles the type of images that one obtains with long focus mirror
lenses that have a tendency to exhibit light colored bubbles.
Thanks for showing the entire photo.
Roland F. Harriston
From rangefinder mailing list:
Date: Thu, 11 Jul 2002
From: Douglas Green dougjgreen@att.net
Subject: RE: okeh dokeh what is bokeh?
I wanted to point out an interesting thread on another forum, where I
got into a debate with most of the rest of that BB about the relative
quality of 3 different Nikkor lenses from entirely different
generations. The thrust of the initial poster was over which lens was
sharpest. But I took a very contrarian position in that thread, by
contending that the sharpest lens in the group had the worst bokeh, and
hence I would have placed it last of the 3. In addition, I felt that
while one lens was very poor on sharpness and contrast, the fact that it
had really nice bokeh helped to enable it to make a very attractive
photo despite it's technical shortcomings. I was clearly outvoted by
that forum, but there are alot of unsophisticated beginners that
participate in that venue. I'd be really interested to hear what others
here think about this comparison:
http://forums.consumerreview.com/crforum?14@75.18jFaK22gb6^10@.efacb0e
From: artkramr@aol.com (ArtKramr)
Newsgroups: rec.photo.equipment.medium-format
Date: 18 Aug 2002
Subject: Re: flat, subdued color rendition of Mamiya TLR lenses
>Subject: Re: flat, subdued color rendition of Mamiya TLR lenses
>From: "roland.rashleigh-berry" roland.rashleigh-berry@ntlworld.com
>Date: 8/18/02
>"ArtKramr" artkramr@aol.com wrote
>> >Subject: flat, subdued color rendition of Mamiya TLR lenses
>> >From: "Stefan Geysen" stefg@pandora.be
>> >Date: 8/18/02
>>
>> >I've been using a Mamiya TLR system for the past couple of months, mainly
>> >for B&W. No complaints there, good sharpness and pleasing tonality.
>Visibly
>> >better than 35mm. So far, I can understand all the comments about bang
>for
>> >the buck, etc
>> >But color shots are another matter. The colors seem a bit flat and cold,
>> >they lack punch and have a strange "feel" to them. Having worked with
>Nikon,
>> >Hasselblad CF and Pentax 67 lenses, I certainly notice a difference
>(better
>> >saturation and realism).
>> >Films used: Fuji Astia, Provia an
>>
>> You are talking about the "Mamaya look" which many like. It is a softness
>of
>> color rendition which many prefer who don't like "lollypop" colors. If it
>> bothers you then you might consider moving up to Blad or Rollei or one of
>many
>> other cameras that dont have that problem. I don't think it is just a
>matter
>> of coating. I think it is inherent in the lens design.
>
>But this effect was mentioned covering a wide range of Mamiya lenses so it
>is more difficult to attribute the effect to lens design. The original
>message cited the 55, 80, 135 and 180 Super - all used with a lens shade so
>the range in design is quite large
>http://www.photonet.demon.nl/mamiya/c330s/page_31.html
>
>Because of this I'd suspect the lens coating technique.
>
>But you are right in that the look is a matter of taste. It could be why the
>Mamiya TLR was so popular as a wedding camera if it gave a soft look. That
>way the brides will usually look good since a soft look usually flatters.
> .
>> Arthur Kramer
>> Visit my WW II B-26 website at:
>> http://www.coastcomp.com/artkramer
Yes. Thanks for mentioning the popularity of Mamaya lenses for wedding work due
to the rather romantic softness. The is quality that was seen early on in the
Hugo Meyer Plasmat and the Voightlander Heliar lenses. The designers were
after a look of "roundness" or third dimension.
Arthur Kramer
Visit my WW II B-26 website at:
http://www.coastcomp.com/artkramer
From: rpn1@cornell.edu (Neuman - Ruether)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Goodbye to Zooms
Date: Sat, 17 Aug 2002
"Olaf Ulrich" olaf.ulrich@onlinehome.de wrote:
>Roger leica35@yahoo.com wrote:
>> For many years I shot almost exclusively
>> with a "new" rig consisting of a N8008 and
>> a 35-70 AF f2.8 Nikkor. Eventually I needed
>> more on either end and added a 24mm and
>> a 85mm. I became very involved with the two
>> new lenses and my kit grew to add a 35mm,
>> 50mm and some manual lenses elsewhere.
>> I've been somewhat dissatisfied with many of
>> my pictures, especially those of people where
>> I was trying for more intimate results. It
>> turned out to be the background that wasn't
>> doing what I wanted. [...]
>> The zoom produced much more of a blended
>> or creamy background that my primes.
>Yes ... many Nikkor lenses are notorious for rendering the
>unsharp background in a harsh and unharmonious way -- it's
>called 'bad bokeh.' Obviously your AF Nikkor 35-70 mm is
>one of the few exceptions among the Nikkor lenses. This is
>not typical for prime lenses vs zoom lenses but a well-known
>Nikon problem.
>
>If you can, try shooting with manual-focus Minolta Rokkor
>or Leica lenses---these generally have good bokeh.
Some of us prefer the "hard-cutting" image of
"bad bokeh" lenses, which can actually aid
achieving good DOF and the appearance of sharpness
for nearly-focused infinity-subjects. Also, some
kinds of images can depend on "bad bokeh" (which
I consider "good bokeh"...;-) - see:
http://www.ferrario.com/ruether/sunplant1.html
for some examples... Thinking that only one style
of representation is ideal is limiting - I find
the concept of a focused "subject", with a soft
"non-subject" surrounding, both boring and
short-sighted - a photograph consists of everything
within the borders of the image, not just part of
it, with other parts relegated to "background"
or "unimportant" status... (all parts of a graphic
image are important). I prefer lenses with "the
problem"...;-)
David Ruether
rpn1@cornell.edu
http://www.ferrario.com/ruether
From rangefinder mailing list:
Date: Thu, 05 Sep 2002
From: Douglas Anthony Cooper douglas@dysmedia.com
Subject: Re: bad lenses
> In a message titled "Ricoh GR1", Drayton Cooper praises the Ricoh GR1.
> The praise is valuable and interesting....
Help! I am not Drayton. Too many D. Coopers floating around the
photography world. (I'm also constantly mistaken for another Douglas
Cooper, a noted cinematographer -- in New York I used to get his mail.)
> Drayton (sic) says (I think in the context of a 377*566 jpeg of a photo):
>
>> The other crucial aspects you want to judge *can*
>> be determined by a Web photo, if roughly: light falloff
>> (also numerically indicated, however); distortion (again,
>> quantifiable); and, most importantly, the lens's
>> character. . . .
>
> For a large jpeg (which is perhaps what you anyway had in mind), yes of
> course they can.
>
> But for such a small jpeg, hmmm. I hadn't thought of light falloff or
> distortion. (Are these issues with rival lenses?) The lens's character?
> (You go on to talk about "bokeh" and [with reservations] saturation and
> contrast.) I wonder. That's not my polite way of disagreeing; rather, I
> mean what I say: I wonder.
This is a constant source of disagreement, even among serious lens
aficionados, but I'm determined that the character of a lens matters as much
as any other aspect. I had a banged-up Zeiss 50/1.4 from the late 40's,
with coating flaws, some haze, etc., and it was only moderately sharp,
flared like nothing else, and yet was as good a portrait lens as I've owned.
(I'm sorry I traded it away.) Not simply because it was a touch soft, but
because the background properties were straight out of Renoir. On the other
hand, I've been using my most recent lens -- the vaunted Contax 28/2.8 for
SLR, and I've found that it has the properties that made me get rid of this
same lens years ago: it has a confused and distracting bokeh. This time,
however, I'm going to keep it because I appreciate the other things it can
do: it's unbelievably sharp, with minimal light falloff and distortion. So
I'll just do my best to keep specular highlights out of the background.
> My uneducated guess is that, stopped down a bit (and not too much), all
> prime lenses of non-extreme focal lengths put out in the last decade or
> so under respected names are good.
>
> Can you name a recently prime lens (whether or not permanently attached
> to a camera) -- not an ultrawide or a telephoto (or any species of freak)
> -- that was recently marketed under a respected brand name, whose images
> you dislike? Images whose mediocrity (or worse) would be apparent if
> carefully scanned and presented as (say) a 377*566 jpeg?
>
> Or even simpler: Of recently produced lenses (or camera-lens combos)
> initially sold for medium or large sums, which are the worst?
Well, this is subjective, but I can tell you that the most famous 50/1.4 on
the planet doesn't make me very happy: the Contax for SLR. It may be the
sharpest fast normal lens out there, but again -- the bokeh is pretty dire.
I much, much prefer my slightly less sharp Canon 50/1.4 LTM, for what it
does in the background. By most reports the 35/2 for the Contax G is a bit
of a clunker -- haven't tried it personally. The Contax 25/2 for SLR does
terribly in sharpness tests (although some like its character a lot). I'm
concentrating on Zeiss, only because that's my current obsession. When it
is good, it is very very good, and when it is bad, it is not precisely
dreadful, but not worth the cash.
Lots of people are pretty unhappy with the character of the very expensive
Leica Asphericals -- perhaps the sharpest 35mm lenses made. They're just
not very pleasant: the words "hard" and "clinical" come up a lot. I've
talked to people who are selling the 35/2 ASPH Summicron in order to buy the
earlier version.
Many of these attributes can be determined by examining a photo on the Web.
Almost all can be spotted clearly in a quick print from a one-hour photo
lab.
I'm having a great time with a lens considered by many, including myself, to
have the finest bokeh in the world: the 150mm Rodenstock Sironar-S for
large format. Unless you're an f64 type, out-of-focus characteristics
matter a *lot* in 4x5, and this lens's superiority is instantly appreciable.
Hope there's enough rangefinder content in this post to keep it relevant...
from rollei mailing list:
Date: Thu, 05 Sep 2002
From: Eric Goldstein egoldste@earthlink.net
Subject: [Rollei] Re: 120mm v. 150mm lens
Stuart Phillips wrote:
> True you don't always want a razor sharp image. But it's probably easier to
> make a lens less sharp with a Softar, than more sharp with a ...?!
The look is different. Classic portrait lens design usually retains some
uncorrected (or under-corrected) spherical at large apertures and yield a
"sharp, yet smooth" look which you cannot get with a filter...
The 150 Sonnar is mostly used for heads and so my guess is it was designed
accordingly... I don't particularly care for the look of this lens but it is
ubiquitous to say the least...
Eric Goldstein
From hasselblad mailing list:
Date: Sun, 8 Sep 2002
From: Austin Franklin darkroom@ix.netcom.com
Subject: RE: [HUG] What's the big deal...
Ken,
Sharp CAN be good...but that, combined with bad bokeh, makes for some horrid
images!
What I meant by saying the Fuji lenses are sharp, was stating one of their
virtues, and contrasting that with one of their detriments. Some people
extol that Fuji lenses are sharp, which they are, and then conclude they are
great lenses because of that...and for some people, that may be true...but
there is more to the image than sharpness for a lot of people.
Austin
> Austin:
> I have always thought that a sharp lens was good, now you seem to be
> saying that it is bad. Could you explain the sharpness issue. Thanks!
> Ken
>
> ----- Original Message -----
> From: "Austin Franklin" darkroom@ix.netcom.com
> Sent: Sunday, September 08, 2002
> Subject: RE: [HUG] What's the big deal...
>
> > My experience, from having owned quite a few Fuji MF cameras, is the lenses
> > are horrid. They are sharp and have horrible bokeh. That's a problem.
> > Yes, I understand Fuji makes great LF lenses according to some...but that's
> > not MF. I would not want to put my money into any Hasselblad Fuji lenses
> > until they have become well knows as being equal to, or better than, the
> > lenses they are replacing. I'm quite skeptical.
> >
> > It IS a big deal.
> >
> > Austin
From hasselblad mailing list:
Date: Sun, 08 Sep 2002
From: Jim Brick jim@brick.org
Subject: Re: [HUG] What's the big deal...
Get a copy of the May/June 1997 Photo Techniques. Much of the magazine is
devoted to Bokeh. Articles are: "What is Bokeh," "Bokeh Terminology," and
"A Technical View of Bokeh."
Read this to clear up anything you don't understand.
Jim
From hasselblad mailing list:
Date: Mon, 9 Sep 2002
From: Ken Martin kmartin@ventur.net
Subject: Re: [HUG] What's the big deal...
I have read everything that I can find on the net about "bokeh". It is
always presented as a subjective measurement of how a lens renders the "out
of focus" part of image. While I may or may not agree with Austin on what
is good or bad "bokeh" since it is somewhat subjective, I do agree with him
that the look of a lens is very important to in the process of creating the
photographer's vision.
A few years ago very few photographers discussed the
term or had even heard the term, never the less they knew that some lens produced
more pleasing images than others. I my case I had I had a 500mm mirror lens
that I used in photographing wildlife. The out of focus area in the image
was composed of many hard circles. When I finally was able to afford a
600mm standard lens the results were far more pleasing because the out of
focus area were much softer. The difference is extreme and most on this list
would consider that the 500mm lens had bad bokeh and the 600mm had good
bokeh.
There was also a posting about the Xpan 45mm. Bokeh would become less of a
consideration in landscape work since most landscape photographers usually
want the entire image to be sharp. Portrait work on the other hand would be
degraded with bad bokeh since the backgrounds are usually out of focus and
bad bokeh would detact.
I my humble opinion each lens has a "look" to it. Some lens are tack sharp
with poor bokeh, some lens are softer with good bokeh, some lens tack sharp
with good bokeh and then some lens are, well, just not good lens at all.
That look is comprised of the effects of focal length, speed,
sharpness/contrast, color, and bokeh. Obviously, if Hasselblad is
considering changing the manufacture of its lens there may be a change to
the "look" they produce. Should that be of concern, you bet!
Ken
----- Original Message -----
From: "David Gerhardt" davidgerhardt@mindspring.com
> Is there a way to "measure" Bokeh? I'm not trying to be tedious; it's just
> that this comes up on the HUG now & again and always in a very qualitative
> sense (for some reason, I always picture Darth Vader speaking of not
> "underestimating the bokeh of the Force..." ;-). Is there some technical
> definition of (and process for measuring) this attribute of lenses; so that
> one might be able to see how the different lens manufacturers "balance"
> bokeh against the various other characteristics?
>
> Or is "bokeh" sort of an "integral-mean" value of the other (sharpness,
> contrast, MTF...) lens characteristics?
>
> (ps: if this has already been previously discussed at length, a reference to
> the archives would avoid "rewinding" the thread...)
>
> --
>
> David Gerhardt
> davidgerhardt@mindspring.com
From nikon MF Mailing list:
Date: Tue, 24 Sep 2002
From: "Roland Vink" roland.vink@aut.ac.nz
Subject: Re: 500mm Reflex lens-Bokeh?
> I also heard about the "perfect number" of diaphragm blades affecting
> the image.
The shape of the diaphragm effects the shape of out of focus
highlights. Generally, lenses with an odd number of diaphragm blades
produce more pleasing effects. An even number looks too "square" or
regular, odd numbers look more balanced. In reflex lenses, the shape
of the diaphragm is donut shaped, due to the center mirror, so blurs
are donut shaped (what would do without donuts to describe this?)
Imagine a picture of a person with trees behind, multiple reflections
from the leaves cause a dappled effect in the background. Ask youself,
would the out-of-focus leaves look more pleasing if they were rendered
with 5, 6, 7, 8, 9 sides?
Also, when stopping well down, reflections or diffraction effects
from the edge of the blade can cause star-burst effects. An even
number of blades gives rise to the same number of points - 8 blades
cause 8 point stars. With an odd number of blades the number of points
is doubled - 7 blades gives rise to wonderful 14 point stars.
Nikon does well in this area, having 7 blades in most lenses, and 9
for high-speed or telephoto lenses.
> I don't know what term to use exactly, is this "bokeh" I don't know??
> There must be some real test numbers that could prove or disprove it
Bokeh is a word which covers the rendering of out of focus subjects.
Unlike sharpness or resolution which can be measured, bokeh is a more
subjective concept, it is difficult to put a number on it. I can think
of three factors relating to bokeh:
1) The shape of the blur - affeced by the diaphragm as described
above.
2) How much the background is blurred. For more blur, increase the
focal length, speed or magnification of the lens. For bokeh by the
bucket full, photographers use long fast lenses like 300/2.8, which
can completely blur out the background. Subtle effects can be obained
where the background is enough in focus to be recognisable and give
context to the subject, but slightly softened so attention stays on
the subject.
3) Hardness or softness of the blur. Imagine two lenses with the same
focal length and speed. One renders the background blurs with soft
edges so the background blends smoothly together. The other renders
the blurs with a hard edge. Both have the same "amount" of bokeh, but
the quality is entirely different. Which do you prefer?
This is mostly affected by how the lens is corrected for spherical
abberations. Nikon lenses tend to be over corrected, which leads to
high contrast effects and hard bokeh in the background. The 105/2.5 is
an exception, and the DC lenses have adjustable bokeh.
From nikon MF Mailing list:
Date: Mon, 23 Sep 2002
From: John Albino jalbino@jwalbino.com
Subject: Re: Re: 500mm Reflex lens-Bokeh?
Roland Vink wrote:
>Bokeh is a word which covers the rendering of out of focus subjects.
>Unlike sharpness or resolution which can be measured, bokeh is a more
>subjective concept, it is difficult to put a number on it.
Another point about bokeh I should have mentioned the other day --
In this digital age, in-camera bokeh really doesn't matter any more,
because it's relatively easy to "bokeh" an image to your heart's content in
Photoshop. As an example, I quickly tried fixing Bob Monahan's example of
"bad bokeh" -- the link he posted a few messages ago, and pretty easily
smoothed the background.
That's one of the nice things about digital manipulation -- virtually any
shooting fault can be "cured" or corrected with one Photoshop technique or
another.
For those with Paintshop Pro -- same thing. With either program, just
select the area you want to "bokeh" (best to create a new layer to play
around with) and then blur it until you're satisfied.
Ah, post-production. Ain't it great!? {g}
--
John Albino
mailto:jalbino@jwalbino.com
From nikon MF Mailing list:
Date: Thu, 3 Oct 2002
From: Koskentola Jaakko jaakko.koskentola@bof.fi
Subject: VS: 180 mm options
Dave asked:
> I have decided to add a 180mm lens to my bag. My question is should I go
> for
> the AIS-ED lens or the new AF lens? I understand the AF lens is excellent
> and focuses closer than the manual focus. I will use it with MF and AF
> bodies but frankly don't often use auto focus on that body. How is the
> manual focus performance of the AF lens? Is there any optical performance
> difference?
>
I suggest you visit this site:
http://www.nikon.co.jp/main/eng/society/nikkor/n10_e.htm
giving info about the history of this remarkable lens. A brief summary of
the main findings as regards the differences of mf and af models:
'"AI AF Nikkor ED", in particular, gives uniform and sharp image from
infinity to the closest distance due to Nikon's original IF system, as is
expected of the latest design.
"AI Nikkor ED" gives excellent performance from infinity to medium
distances, especially the clearness of color is superb.'
And:
'On the other hand, the coloring of the fringe of defocus with "AI Nikkor
ED" is very little and the defocused images appear smooth.
This is similar to "AI AF Nikkor ED" as well, images taken are so alike that
sometimes we cannot know the one from the other depending on the shooting
condition.
If I am pressed to mention the difference, with "AI Nikkor ED", the defocus
linked from the focused plane to the front defocus appears hard, and with
"AI AF Nikkor ED" the rear defocus just behind the focused plane appears
hard.'
The latter basically means that the lenses differ in their bokeh: with MF,
the background bokeh is smooth and front harsh, and with af, vice versa. You
choose which is more important for you kind of photography.
... jaakko koskentola
Date: Wed, 23 Oct 2002
From: Douglas Anthony Cooper douglas@dysmedia.com
To: contax@photo.cis.to
Subject: [Contax] Re: Bishi or Honwaka?
> I don't think these terms are about "bokeh" itself. For describe "bokeh"
> Japanese photographers just use "beautiful" and "ugly".
> (though, there are "double line bokeh", etc, the terms to descrive the
> characteristics of bokeh.)
>
> "Honwaka" type of lenses, or I can say P50/1.4 and P85/1.4 are softer
> at F1.4, it means from focused range to unfocused range, there are
> some amount of blur-ness, that brends well, and it is their characteristic
> some love and some hate.
Okay, this is yet a third definition. All very interesting. I've heard
"bokeh" used in two ways: it either describes the quality of the background
image, or the *transition* from sharp to blurred. It seems that
bishi/honwaka refers to this second definition. Although spherical
aberration is said to affect the first category as well.
Looks as if we might require a PhD thesis after all...
Date: Thu, 24 Oct 2002
From: muchan muchan@promikra.si
To: contax@photo.cis.to
Subject: Re: [Contax] Re: Bishi or Honwaka?
...(above posting quoted)
No, you mix when I talk about the word "bokeh" and the word "honwaka".
"bokeh" simply means "out-of-focus", "honwaka" is someone's description
about this type of lenses. The relation of two words are only that
some photographers thinks that "honwaka" type lenses (or just P50/1.4 and
P85/1.4) has beautiful bokeh. But, for example, P100/2.0, which is not
"honwaka", has also very beautiful "bokeh".
So the two words are not directly related.
The difference between P85/1.4 and P100/2.0 at wide open is,
(I mean, the difference of typical "honwaka" lens and typical "bishi!" lens is)
that P85 at f1.4, the _focused_part_ has more blurness than P100 at f2.0.
-- technocally, having "less corrected aberration", or having "lower MTF"
at wide aperture. -- but I'm not very technical person, so maybe it is
not true.
About the two definitions of 'bokeh", I don't see two definitions.
If the "out-of-focus" part is beautiful, then transition is smooth,
or if the transition is not smooth, "out-of-focus" part won't be beautiful.
Many people thought it to be related to blade shape, but I don't think
blade shape is the first importance, (except exotic "triangle" shape of
Planars for Rollei 35mm SLRs...), more important is what kind of aberration
the out-of-focused part shows. When a point source of light is diffused by
putting away from focus distance, if the light diffuse smoothly, (further
from the center point, less bright), blured images from many point sources
next to each other will blend smoothly. If a point of light is diffused
unevenly, like making a brighter circle around the point, blured "ciercles"
from many point sources next to each other will blend rather randamly,
somewhere more intense and somewhere less intense, that's the case we
often find as "ugly bokeh". This is my understanding about "beautiful bokeh".
> Looks as if we might require a PhD thesis after all...
I don't think so.
muchan
Date: Mon, 28 Oct 2002
To: Russiancamera-user russiancamera-user@mail.beststuff.com
Subject: Re: [Russiancamera] Review of Russian lenses???
From: Michael Lee mlee777@bigpond.com
Mir-3b (65mm) and the Volna 3 (80mm) for the Kiev 88 'B-mount'.
Their 'bokeh' is not as smooth as I like. I've compared the Volna 3 side by
side at or near full aperture with a Carl Zeiss CF 80mm for the Hasselblad
500. On a shot with some out of focus bricks, the Volna exhibited some hard
elements of "defined sharpness" to the mortar area of the brickwork - like
looking at a ridge, with a clearly visible ridgeline. The Carl Zeiss' blur
is smooth - no distinct "ridgelines".
Mike,
Melbourne, Australia
From nikon mailing list:
Date: Wed, 30 Oct 2002
From: John Jungkeit junkit2@yahoo.com
Subject: Re: [Nikon] Nikon 105 f/2.0 question
To: nikon@photo.cis.to
I have owned a 135 2.0 for several years now and find
it my portrait lens of choice. For that purpose, I
believe it surpasses the 80-200 2.8. You need not
"master" the defocus feature (it varies) but you do
need to find the best setting that works for you.
I also have 85 1.4 which is also excellent for this
use, but hey, I have the 135 so why bother with
anything else (for portrait).
John
From: JR jr@nowhere.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Nikkor Defocus Control portrait lenses
Date: Wed, 30 Oct 2002
"Jan Werbiski" janwer@pa54.zgora.sdi.tpnet.pl wrote:
> Hello
> What do you think about Nikkor 105 and 135 mm DC lenses?
> Where can I see pictures taken with normal 105 and 135 next to DC version?
>
> Do you have any experience with this lenses? Are they worth the extra cost?
> What is the best portrait lens for Nikon to make portraits of 1-5 people in
> studio and outdoors?
> TIA
> --
> Jan Werbiski
Jan,
What body you are going to using? If you are using any body other
than the N(F)55, 65, 80 or D100 then I would not get a Nikkor DC lens, I
would get the manual focus Nikkor 105/2.5 AI or AIS. This is an
excellent lens, some say the best portrait lens for a 35mm camera
period. You can find these in good condition for $200. This will meter
with a body other than those I listed and will perform almost exactly
the same. I doubt you could see a difference from a scan on a monitor.
Now MAYBE a 16x20 enlargement may show very slight differences, but I
doubt it. The DC lenses mainly allow you to blur the background while
keeoing the suvject in focus, something the aperture on any lens does.
This is only helpful in bright light situations and fast film. Like a
very sunny day using 800 speed film and you want a photo where the
person is in focus but the background is blurred. This would be hard to
do without the defocus controls because you would be using a small
aperture like f16 which would give a very large depth of field. You can
put a ND filter on your lens and allow it to open wider, giving you a
more shallow depth of field. From those that have the DC lenses, they
usually say they don't use that feature at all. For 1-5 people
portraits, you might need something wider than 105 and definately wider
than 135 unless you are going to be 50 feet from them. A 85/1.4 AF-D
may be the lens for you. This is a popular length for the "classic"
portrait. You can get the 85/1.4 AF-D and the 105/2.5 AIS for less than
a 105/2 DC...That would be my suggestion. The you have more
photographic possibiliteies and 2 EXCELLENT lenses. Now if you have the
N(F)80, then a 105/2 DC is a better option because that body won't meter
with a manual focus lens without a CPU chip in it. It would be worth it
to sell the N80, then get a F100 and the 105/2.5 AIS. The 105/2 DC is
$919, the F100 is $899 the 105/2.5 AIS is $200. The 85 1.4/AFD used is
about $600.
JR
Date: Thu, 31 Oct 2002
From: Mike Benveniste mhb@clearether.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Nikkor Defocus Control portrait lenses
Jan Werbiski wrote:
> Thank you.
> Currently I have F100 but I plan to buy another body soon and it will be
> D100 or Fuji S2.
> What about 80-200 2,8 or 70-200 2,8? I had the former and it was very nice
> lens for portrait. Zoom is good for my work because I don't have too much
> time to come closer etc.
As much as I like an 80-200 2.8, it's about my last choice for
portraits, especially if it's a mix of individuals and groups.
For individuals, you end up lugging a bunch of weight to no
real benefit. For small groups, I often find ye olde 50 mm works
best. A 50 mm lens may be boring out-of-fashion glass, but the
pictures you get from one don't have to be. Fast, sharp and cheap
aren't necessarily bad things.
Without knowing a little more about why you feel you need one,
I wouldn't want to count the number of zooms that could work for
you. There are a dozen or so current offerings from Nikon, at
least that many from third parties, plus almost 40 years of used
stuff. 43~86mm, anyone?
Otherwise, Have you tried your Sigma 90 as a portrait lens? I've
had good luck using similar lenses, but if you have to focus
manually it takes some practice with small adjustments.
--
Michael Benveniste -- mhb@clearether.com
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Nikkor Defocus Control portrait lenses
Date: 31 Oct 2002
T. P. t.p@noemailthanks.com wrote
> ski2photo@netscape.net (Jerry L.) wrote:
>
>
> In my view, the 55mm and 60mm Micro-Nikkors are about the last lenses
> you should consider using for group portraits.
>
> The f/2.8 maximum aperture does not allow sufficient isolation of the
> subject from the background, and the lenses' rendition of out of focus
> (OOF) areas of the shot is quite appalling. OOF highlights tend to be
> extremely harsh.
If you are referring to the 55mm f/2.8 AIS Micro-Nikkor then I'm
puzzled by your statement. This lens has quite good bokeh - certainly
far better than the 35mm f/1.4 you were recently praising in this
respect. Its completely wrong to call its bokeh "appalling". Would
you care to share some images that illustrate your point?
Brian
www.caldwellphotographic.com
From leica topica mailing list:
Date: Sun, 8 Dec 2002
From: "Felix Lopez de Maturana" fmaturana@euskalnet.net
Subject: RE: Photonet folders
In my photonet workspace there are three folders that can help to discern
about the difference among pictures taken with Canon, Leica and Nikon as the
three folder have been shooted with cameras and lenses of the three
different brands. In my opinion the main difference is not in sharpness or
distortion quite similar but in out of focus images that in Nikon case,
excellent images otherwise, is not very pleasent. Excuse me the subject I've
chosen for the Nikon folder, rather sad...
Kind regards
Felix
Leica : http://www.photo.net/photodb/folder?folder_id=250582
Canon : http://www.photo.net/photodb/folder?folder_id=247399
Nikon : http://www.photo.net/photodb/folder?folder_id=258636
From minolta mailing list:
Date: Tue, 31 Dec 2002
From: "Michael Hohner" miho@nefkom.net
Subject: Re: 50mm f1.4 AF Lens Bokeh Example
"lwyau" lehwenyau@hotmail.com wrote:
>The resulting bokeh's have distinct rims. "Good bokeh" is supposed
>to be fuzzy on the boundary. I suppose then this lens is
>producing "bad bokeh"...
I didn't look at the picture, but:
A lens with a good bokeh is supposed to render out of focus highlights
as round discs with uniform light distribution. A disc with a light
center and dark rim or light rim and dark center, or non-disc shapes
(sexagons, octagons, triangles etc.) are considered bad bokeh.
---
Michael Hohner
miho@nefkom.net
http://www.nefkom.net/miho
From: rpn1@cornell.edu (Neuman - Ruether)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Aberrations, DoF
Date: Thu, 30 Jan 2003
glhansen@steel.ucs.indiana.edu (Gregory L. Hansen) wrote:
>In another thread I quoted an abstract of an article that explains the
>spherical and irregular aberrations in the human eye increase the depth of
>field at some cost in acuity.
>
>That had me wondering, is there any such thing as a camera lens with
>aberrations purposefully built into it for an increase in the depth of
>field? Would there be any use for such a lens? Maybe for very long
>telephoto with wide aperture, for instance. I've seen pictures of animals
>where the face was in focus, but the fur farther back on the body was not.
>Maybe some aberration but a larger depth of field would make a more
>pleasing picture.
I have never placed the Nikkor 500mm f8 (f8 1/2 in
practice, earlier-type) next to a standard-design
500mm lens shot at f8 1/2 for comparison, but the
Nikkor mirror, with its hard-edged and complex-looking
out-of-focus area imaging (otherwise known as "bad
bokeh"...;-) and "doughnuts" does appear to have more
DOF than one would expect from a 500mm, with areas
that would normally be expected to look soft in the
image retaining a sense of detail and focus - and it
is often possible to take photos with it that appear
to have deep DOF, as when shooting a building face
at an angle, or a distant patch of ground, etc. I
once shot a series of building details (from tiny to
very large) with the Nikkor mirror for a couple of
magazine articles - and almost all the images appear
to have universal DOF, regardless of the shooting
angles...
David Ruether
rpn1@cornell.edu
http://www.ferrario.com/ruether
From: rpn1@cornell.edu (Neuman - Ruether)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Aberrations, DoF
Date: Fri, 31 Jan 2003
"Toby" zdftokyo@ggol.com wrote:
>The actual DOF is the same, but the double-edge produced by the mirror gives
>the sense that the OOF areas are sharper. If you doubt this paint or paste a
>black spot in the center of a filter and mount it in front of a normal
>refractive 500 mm. Come to think of it this might act as a quasi-diaphragm
>by limiting the size of the front objective and thus would increase DOF
>somewhat. Don't forget that an f8 mirror lens has an effective T-stop of
>about f10.
>Toby
Lenses with "over-corrected" spherical abberations (the
Nikkor mirror is one) will produce a "harder" rendering
of far-side out-of-focus image parts - and this will aid
in the appearance of increased DOF on the more important
side of focus (where the "finer-scale" detail is likely
to predominate); "DOF" is a visual thing, not a mathematical
thing, so the DOF *can* be different for two lenses set
up the same way, but with different optical characteristics
beyond the basic FL, etc. (and, yes, the "doughnuts" can
help with this...); and I did mention that the mirror was
not truly f8 ("f8 1/2")...
David Ruether
rpn1@cornell.edu
http://www.ferrario.com/ruether
From: "Q.G. de Bakker" qnu@worldonline.nl
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Tell me more...
Date: Wed, 5 Feb 2003
PSsquare wrote:
> Please describe a "waterhouse stop". It is a new term to me and would
> appreciate some description.
It is a plate with a hole in it that is inserted in to the (process) lens.
The hole has a particular size, and shape, and you need different plates
with different sized holes to mimic an adjustable iris diaphragm.
The shape of the hole was square, because like that it made better raster
images.
From: "Q.G. de Bakker" qnu@worldonline.nl
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Tell me more...
Date: Thu, 6 Feb 2003
Alan Browne wrote:
> ...with a square hole, the bokeh also looks like crap.
That's where you are wrong.
The "bokeh" then is exactly what is needed to get nice rasterized images
when a continuous tone original is copied with a raster mesh screen. A
circular aperture would not have nearly as good "bokeh".
From: "Q.G. de Bakker" qnu@worldonline.nl
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Tell me more...
Date: Wed, 5 Feb 2003
PSsquare wrote:
> Please describe a "waterhouse stop". It is a new term to me and would
> appreciate some description.
I think (don't know the lens mentioned, but itsounds very similar to the
Imagon) the correct term to use for the thing Gordon mentioned is
sieve-diaphragm.
The outer parts of a lens contribute most to (spherical) aberrations.
Stopping down using a regular iris diaphragm (or Waterhouse stop) excludes
these outer regions first, leaving only the central part to contribute to
image formation. No outer parts means no (orless) aberration and no soft
effect.
The solution to this is to insert a disk with several holes distributed in
such a way that the ratio of (unobstructed) outer to center parts,
contributing to image formation, is maintained, while still reducing the
total area of the aperture as needed.
From: "Philip Coghlan" philip.coghlan@virgin.net
To: contax@photo.cis.to
Subject: Re: [Contax] Re: Bishi or Honwaka?
Date: Thu, 24 Oct 2002
-----Original Message-----
From: muchan
>
>About the two definitions of 'bokeh", I don't see two
definitions.....snip
Muchan
You may well know this already, but there is an article by Harold
Merklinger on bokeh published in Photo Techniques, May/June 1997. It
was on a website I have listed as www.smu/~rmonagh/mf/bokeh/html. This
does not seem to be accessible any longer, so I have summarised some
points from it. It seems to confirm some of what you say, but differs
in places.
1. He does think that diaphragm shape affects bokeh, but his tests use
an extreme example of a triangular aperture to demonstrate it. His
opinion is that a circular aperture is neutral.
2. His judgements and measurements are based on the appearance of
out-of-focus highlights.This can very from lens to lens, irrespective
of the aperture shape. According to his results, the appearance of
these highlights can depend on how spherical aberration is corrected
in the lens design. Over correction can lead to bright rings around
the highlights behind the image plane, and this, he believes,
contributes to bad bokeh. As I think you have suggested before, bokeh
can differ from one side of the image plane to the other, but
out-of-focus backgrounds are usually of more concern to us than
foregrounds. The opposite effect, ie bright cores to the highlights,
is more acceptable and leads to better bokeh, he thinks, providing the
core is not too noticeable. So, it would be possible to have a lens
with both "good" and "bad"bokeh, but we are more likely to base our
judgements on background rather than foreground effects.
3. To achieve neutral bokeh, ie, even highlights with neither bright
rings or cores, he observes that it is necessary to tolerate some
degree of aberration.
This is just a summary, but I hope I have fairly captured the essence.
Regards Philip C
Date: Fri, 25 Oct 2002
From: muchan muchan@promikra.si
To: contax@photo.cis.to
Subject: Re: [Contax] Re: Bishi or Honwaka?
Philip Coghlan wrote:
>
>>About the two definitions of 'bokeh", I don't see two
> definitions.....snip
> Muchan
>
> You may well know this already, but there is an article by Harold
> Merklinger on bokeh published in Photo Techniques, May/June 1997. It
> was on a website I have listed as www.smu/~rmonagh/mf/bokeh/html. This
> does not seem to be accessible any longer, so I have summarised some
> points from it. It seems to confirm some of what you say, but differs
> in places.
>
I don't think his view differs much from mine.
-- these days I'm only writing negative sentenses like "I don't think..." ;)
> 1. He does think that diaphragm shape affects bokeh, but his tests use
> an extreme example of a triangular aperture to demonstrate it. His
> opinion is that a circular aperture is neutral.
>
Sure, diaphragm shape affects bokeh, especially when bright point light
is out-of-focused. Odd shape of diaphragm like saw-shape of some old AE
lens, or triangle of Planar for Rollei, will be seen on the background.
But, a simple fact, that at widest aperture, for all these lenses,
aperture shape is circle, but not all the lens show the same degree of
"beautiful bokeh", there must be more facter in the optical design itself.
> 2. His judgements and measurements are based on the appearance of
> out-of-focus highlights.This can very from lens to lens, irrespective
> of the aperture shape. According to his results, the appearance of
> these highlights can depend on how spherical aberration is corrected
> in the lens design. Over correction can lead to bright rings around
> the highlights behind the image plane, and this, he believes,
> contributes to bad bokeh. As I think you have suggested before, bokeh
> can differ from one side of the image plane to the other, but
> out-of-focus backgrounds are usually of more concern to us than
> foregrounds. The opposite effect, ie bright cores to the highlights,
> is more acceptable and leads to better bokeh, he thinks, providing the
> core is not too noticeable. So, it would be possible to have a lens
> with both "good" and "bad"bokeh, but we are more likely to base our
> judgements on background rather than foreground effects.
>
Each lens has it's designed focus distance. In case of Planar 85/1.4,
it's from about 0.8m to infinity. It means, we can assume that the
designers corrected aberrations for that range of focus, (maybe for
the flange distance of given mount, if extention is used, it can focus
closer but loose infinity focus), within this range, the lens is capable
of focus a point light to a point, or "very close to point". but when
the light is not focused, it means some milimeter (or micrometers?) of
the film plane, the image of the point light source is bigger than a point,
If the light source is within the range of this designed distance, this
blurred image is still something close to point, but if it is out of the
range, typically when it's too close, the blurred image shape is undefined,
or designers may not have cared at all. If we distinguish the "foreground
bokeh" and "background bokeh", I think the problem is only with
"forground bokeh" of object closer than the lenses designed focus distance.
> 3. To achieve neutral bokeh, ie, even highlights with neither bright
> rings or cores, he observes that it is necessary to tolerate some
> degree of aberration.
>
Each lens designer, or each team of lens designers has their own philosophy,
or aethtetic sense, or aiming value, or target niche of buyers, and so they
will correct the optical aberrations in different creterias. Zeiss and Leica
lenses are know with beautiful bokeh, IMHO, it's a consequence of their
creteria, of what optical quality the well focused image should have,
and the distribution of that "qualities" for various f-stops. I don't say
which company's lens is considered with "ugly bokeh" ;) but I heard they
aimed "finer resolution" and "edge resolution", where Zeiss and Leica's
createria is more about contrast and high transmission rate. Maybe desingers
for "finer resolution" has overcorrected some aberration, that focused image
is sharp and higher resolution but at out of the range, the image shape is
uncontrolled.
> This is just a summary, but I hope I have fairly captured the essence.
>
> Regards Philip C
If one point to add, viewers "notice" not only the bokeh of bright object,
but react to the "overall feeling" of background bokeh, and it's more about
how each blurred-light-from-the-points next to each other, blend. If this
each b-l-f-t-p conserve the core information of the original point, and
doesn't contaminate the neigbor b-l-f-t-p's core information, the total
bokeh image still conserves the original information of the unfocued subjects,
making them more "usable" for image making although they are not shaply focued.
With portrait lenses, for "thin focued on eye-lash" type of photo, the skin
or nose of other part of image is all in "bokeh" in strict term, but if the
unfocued subject still conserve the original information well, and blend well
with neigbor b-l-f-t-p, it can be seen as "pleasantly soft".
(I'm just writing how I interpreted what I read, and so no disclamer if it's
right interprtation or not..., I'd be rather glad if someone correct my
mistake.)
muchan
from nikon mf mailing list:
Date: Thu, 27 Feb 2003
From: "bryce hashizume" bwv812@hotmail.com
Subject: bokeh
You can't really see much evidence of bad bokeh in your pictures, but your
backgrounds are almost purely black. And in the picture with the white
doorframe (?) on the left, it is a very simple linear pattern, and not that
much out of focus, both of which helop it look smooth.
If you need convincing, look at: http://www.trenholm.org/hmmerk/ATVB.pdf
If you dont think the double spires of the cathedral look strange, I'll be
very surprised. Sure, it is an extreme example, but it illustrates the
point. If you can get a hold of a copy of the issue of Photo Techniques that
this article appeared in, you can see other (and more conventional) examples
of good and bad bokeh.
You can also look at http://www.flarg.com/bokeh_sketch.pdf to see a simple
scene rendered with different bokeh. These images come from a bokeh
simulator at http://www.flarg.com/bokeh.html, but I think it helps if you
can see all the different kinds at the same time, as the differences are
more subtle than in Makerink's example. Personally, think they may be too
subtle, as real backgrounds are usually more complex than Buhler's sample
target, which results in much harsher renderings.
I hope this helps,
bryce
From nikon mf mailing list:
Date: Mon, 03 Mar 2003
From: "bryce hashizume" bwv812@hotmail.com
Subject: Re: OT: bad bokeh
> From: "Roland Vink" roland.vink@aut.ac.nz
>
>There are three aspects to the rendering of unfocused objects in the
>foreground and background:
>
>1. The Shape of defocused highlights.
>
>2. The Size of defocused highlights.
>
>3. The Smoothness of defocused highlights.
It is a commons misconception that the effects of bokeh are evident only in
the out of focus highlights, but bokeh applies to all areas of the out of
focus image. If you look at the first image on merklinger's article in Photo
Techniques http://www.trenholm.org/hmmerk/ATVB.pdf, you can see bad bokeh
in the dark areas of the image.
Highlights are usually used as a convenient way to diagnose bokeh, as
specular highlights really stand out from the surrounding image and let us
see how smoothly they are represented. Donut shaped highlights attest to bad
bokeh, while highlights with bright centres lead to good bokeh. This applies
to all out of focus regions, not only the highlights, though. The size of
the defocused highlights is just another way of saying how far out of focus
the back/foreground is, and this obviously aplpies to all out of focus
regions as well.
On the other hand, the number of aperture blades and the shape of the
aperture is something that you only see in the highlights, but I personally
consider this a less important contributor to bokeh, especially since the
effects of various shaped apertures are not apparent in all out of focus
fore/backgrounds. If there are no out of focus highlights in the image you
usually can't tell if the shot was made wide-open, stopped down, or with a
lens having a certain number of blades.
bryce
From rangefinder mailing list:
Date: Wed, 5 Mar 2003
From: Joe Polizzi polizzi@westbend.net
Subject: RE: Aesthetic Evaluation of Prints from Different Lenses
Yes, Frank - This is something that I'm dealing with also; it's gnawing
at me. I need to understand this thing about 'the character of a lens'.
Have you read about this optimization that lens designers do beween
contrast and resolution? I guess that for every lens design the
engineer can decide to lean toward resolution or sharpness, but the
optimization for one is different from the other. If you go all
resolution, then an exeedingly small point of light is rendered at the
film plane as a super-small, SHARP spot with a large, dim 'glow' around
it; if you go the other way it will be rendered as a LARGER spot WITHOUT
the glow. It's the glow that reduces contrast, hence 'resolution vs.
contrast'.
I know that there are tons of other parameters; distortions,
color-related aberrations, flatness of the focus plane - OY. Then I
read (..if I understood this correctly) that some errors in lenses (I
think it was refering to this glowing 'halo-like' area) tend to activate
silver in a more-or-less random fashion, causing a negative's grain
structure to be less-or-more "clumpy".
Then there's the issue of out-of-focus characteristics! I see how on
out of focus highlights (especially wide open, when you can't see the
aperture blades) there is a brighter ring at the edge of the blob. It
seems that a cluster of these highlights can tend to have sort of a
'cobweb'-like pattern because of the way these thin, bright 'rings'
interact.
Yeah - we should look into this some more. Any insights out there?
Joe
Frank Vincent wrote:
> I am trying to define what I can see as different in the prints from various
> rangefinder cameras and lenses I use. Some photos can be sharp, but do not
> have the "snap" that others have. I have even taken pictures of the same
> subject with the different cameras and lenses for comparison, but cannot
> define in words what I see as different.
>
> It is at this point primarily for me an emotional response, which is
> consistent for certain lenses. I use the word "flourescence" for lack of a
> better term. Some images seem to almost glow. After looking at others'
> infrared prints, there seems to be some relationship to them as well.
>
> Anyway, does anyone have any thoughts on this? I am simply trying to
> clarify my thinking on this matter, not get into the definition of art. I
> read a lot of writing on lens quality. I just wonder what others see.
>
> Frank Vincent
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Good 8X10 lens for shallow DOF work?
Date: 23 Apr 2003
Stacey fotocord@yahoo.com wrote
> Just finished up an 8X10 project and can tell from the test shots I want to
> try some very shallow DOF work. The camera came with a 300 f4.5 and the
> shots done wide open look really cool. The only issue is that it's a tessar
> type lens and the bokeh (especially highlights) leaves something to be
> desired. Looking for something (probably an old portrait type lens?) that
> is about this length/speed but that has nice smooth bokeh. Guess I'm
> spoiled after seeing how pretty the bokeh on the CZJ 180 f2.8 sonnar is
> :-)
>
> I'm going to only be doing contact prints so nice smooth bokeh is more
> important than sharpness here. I know nothing about the old glass, any
> clues on names to look for? All I can find on a search is now sharp
> different LF lenses are with no mention on the out of focus areas...
An old 19th century Petzval portrait lens should have much better
bokeh than an f/4.5 Tessar due to the nature of the spherical
aberration correction, and will be significantly faster as well
(f/3.5). However, off-axis performance will suffer quite a bit due to
field curvature. A few modern Petzval lenses are designed with
negative field flatteners to solve this problem. Some of the U-2 spy
cameras back in the 1960's were equipped with fast, high-resolution
Petzval lenses of this type.
Brian
www.caldwellphotographic.com
From: "JanR" jrosseel@toohottomailto.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Date: Sat, 14 Jun 2003
"Gordon Moat" moat@attglobal.net wrote
> Bob Monaghan wrote:
>
> > see http://medfmt.8k.com/mf/bokeh.html
> >
> > the consensus, backed up by the design of the nikon defocus control
> > lenses, is that the "good" bokeh lenses have a degree of spherical
> > aberration that is pleasing to many viewers/users. This effect is most
> > pronounced wide open, when the aberrations in many lenses are maximal,
> > and when the aperture blade effects are most minimal (if an effect at all)
> > as they are retracted and not used wide open, when bokeh is often "best"
>
> This seems somewhat contrary to what I have read. Can you provide a source
> for that design criteria? The reason I question that is because it is
> opposite views presented in sources from Nikon:
>
> http://www.nikon.co.jp/main/eng/society/nikkor/n05_e.htm
>
> This article concerns the Nikon 105 mm f2.5, which I think you could agree
> has one of the best defocus renditions of any Nikon lens, if not of all
> lenses. These series of articles are written by optical engineers, with many
> interviews of the original designers. In this one, it is noted that the
> second design of this lens offered "significant improvements in close-range
> aberration fluctuation, as well as peripheral light, spherical aberration,
> and coma." Since the defocus effects are nicer in this version, than in the
> original Sonner type design, it would seem that at least in this case, less
> gave more (pleasing results).
And further down in this article, the following is stated:
"Basically close-range aberration variation is small, but at portrait
distances the correction for aberration seems to be slightly insufficient.
The insufficiency as far as spherical aberration in particular is what makes
defocus background appeared beautiful."
And this confirms the original statement that presence of spherical
aberration gives good bokeh...
> Ciao!
>
> Gordon Moat
> Alliance Graphique Studio
>http://www.allgstudio.com
With regards,
JanR
Date: Fri, 20 Jun 2003
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Good morning Bob,
Bob Monaghan wrote:
> yes the nikkor 105mm f/2.5 is a classic, pretty nice bokeh for portraits,
> useful for macro work too etc. I have several examples in backup kits etc.
>
> the lenses which often are really bad enough to be good in bokeh are often
> so only wide open or at best 1 or so stops down. Most are in older mounts,
> which is okay if Nikon F and M42. Many don't have any name recognition.
>
> For example, I have a spiratone 105mm f/2.5? which is a clone of the
> nikkor which has even better bokeh in a $10 lens on a T-mount - from a
> dealer ;-) Pre-1970s stuff in the main. When I say bargain, I mean cheap
> ;-) Most dealers leave these in a box under the table at camera shows ;-)
I have an unusual one called a Sima Soft Focus lens. It includes waterhouse
stops for the apertures, though starts at f2 without one installed. This is a
100 mm single element lens, of mostly plastic construction.
> . . . .
> I've started to mess with older MF and LF lenses, and now even some
> projection lenses, to see if I can find some useful and unique lens
> signatures to play with ;-) Many of the older lenses are both nice bokeh
> and a bit soft wide open, ideal for portraiture.
Some lens of the 1920s and 1930s can also be very nice for portrait work. The
tough part is finding one in good enough condition, or being able to clean
the elements. Many of the old triplet designs go for low cost, and there are
many common aspects that make parts interchangeable.
> I have also puttered with waterhouse stop designs (tea strainer etc. as
> with Rodenstock's soft focus lens design) to vary the amount of spherical
> aberration on a Tmount pan-focus (f/40!) lens. This puppy unscrews lens in
> middle, lets you put in a blackened paper "stop", use the f/40 stop
> supplied for panfocus (max DOF), or use no stop at all for max soft focus
> at f/4 or so. Again, another oddball optic with unique effects for very
> low $$
The middle location sounds like a good idea, but why would something on the
end not work?
> lots of interesting lenses and different effects, more often the lower
> cosat lenses are less boringly optimized than the typical third party or
> OEM lens we usually use ;-) Nice bokeh is just one of the things you can
> find in low cost older optics compared to today's optimized lenses ;-)
Some of this stuff is low cost now because it is so old. Many of the older
lens designs may have been somewhat expensive when new, but now are
affordable for some. Even searching for some great examples of the past can
lead to finding some great bargains. Lots of old Nikon AI and AIS lens, some
of the older Leica M choices, early Olympus OM gear, and mid 1980s Pentax,
have enough choices to make anyone on a budget happy.
One issue of older gear is the reliability of older camera bodies. Nikon
still makes a new FM3A that can use many of the older lenses, and
Cosina/VoigtlSnder just introduced a new M42 mount SLR. People who like the
old lenses, but are less confident about older cameras, still have some good
options. Personally, I have nothing against older cameras, and my old gear is
well maintained, but I do understand some people wanting newer gear.
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: Bob Monaghan [rmonagha@engr.smu.edu]
Sent: Fri 6/20/2003
To: Monaghan, Robert
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Hi Gordon,
Yes, you are very right that many of the classic bokeh lenses in various
lines (e.g, nikon) are available now at low prices due to switch to AF and
digital systems. I collect tips on the best bokeh for the various kits I
use (nikon, minolta SRT, M42, K/KA pentax..) and keep my eyes open for
bargains at camera shows etc. ( etc.)
The optimal point for the waterhouse stop is usually in the middle of most
lens designs. I'm familiar with the sima soft focus lens, part of its
charm is spherical aberrations etc. from the single element +10 diopter
lens (see mf/soft.html ).
The older lenses of the 1920s and 30s can be very interesting too for good
bokeh, precisely because they weren't computer optimized ;-)
One useful trick worth exploring is a cheap teleconverter; these often
generate a good bit of spherical aberration on their own, as well as
magnifying the defects of the original lens along with its focal length ;-)
Since many of the classic bokeh lenses are older fast normal lenses, using
the Teleconverter has the added benefit of generating a short telephoto
focal length too. And for lenses that have a bit of nice bokeh, it is one
way of generating more good (and bad) spherical aberrations too ;-)
grins bobm
From: rcochran@lanset.com (Richard Cochran)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Date: 16 Jun 2003
rmonagha@engr.smu.edu (Bob Monaghan) wrote
> However, I believe that the reason blade count is often associated with
> better bokeh lenses is historical and economic. In the past, mfgers made
> lenses with many, many blades or aperture ring elements, and dang the
> expense. Today, mfgers greatly reduce the number to the minimum to cut
> costs.
I'll just point out that some (not all) of those old lenses with
outlandish numbers of aperture blades lacked automatic diaphragms,
because they were for rangefinder cameras, TLRs, view cameras, or even
primitive SLRs without auto diaphragms. I suspect it's much easier
to put in lots of aperture blades if you don't have to figure out
how to get them to move so quickly.
Aperture shape isn't completely irrelevant to bokeh, but you're
absolutely right that aberrations generally play a much larger
part. The DC lenses show that you can radically alter the bokeh
characteristics of a lens without changing the aperture shape
one whit. But it's a lot easier to see and explain aperture shape
than it is to see and explain residual spherical aberration.
--Rich
From: T P tp@nospam.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Date: Mon, 16 Jun 2003
contaxman@aol.comnospam (Lewis Lang) wrote:
>I have a feeling that aspherics may be only part of the story w/ the new
>Leica M wide angles (particularly the 35/1.4 Summilux ASPH I've been hearing
>about). It may be possible to use aspherics to optomise sharpness wide open w/o
>affecting bokeh, they may not be mutually exclusive, but I have the feeling
>that sometimes one (sharpness) is traded for the other (bokeh) regardless of
>the use of aspherics. I wish I had more optical knowledge to confirm or deny
>this so this is only a hunch.
It's a good hunch. Lewis. The latest ASPH lenses for Leica M
certainly appear to have sacrificed bokeh (for sharpness) on the high
altar of the "MTF league table". Since most camera owners think a
sharp lens is automatically a "good" lens, Leica have had no option
but to follow fashion and offer something that is ultra-sharp but with
less pleasing bokeh.
>At least the 50 and 75-150 Series E lenses have great bokeh - don't know about
>the wider angle E/other Nikon lenses though.
We'll never agree about the 50mm Series E, but the 75-150mm has
stunning bokeh. The 28mm f/2.8 Series E has good bokeh, and the 100mm
f/2.8 Series E is a perfectly delightful portrait lens.
>I used to shoot the 25-50
>AIS but usually either stopped down and or at its widest angle setting, and one
>of the shots I took w/ it at or near wide open aperture at its widest angle
>seems a poor way to judge this lens as the background is a backlit white
>bedsheet and any kind of good/bad bokeh lens could handle that situation ;-).
I haven't used that lens, but my 24-50mm AF Nikkor was dire. The
bokeh was harsh to the point of being appalling. However, I am not so
sure that bokeh is of any great significance in any lens with a
maximum aperture of f/3.5-4.5.
>Most Pentax and Zeiss lenses have great bokeh but that doesn't help you if you
>shoot Nikon ;-)
Select the right Nikkors and you will get good-to-excellent bokeh -
85mm f/1.4 AI(S)/AF, 105mm f/2.5 AI(-S), 105mm f/2 DC, 135mm f/2 DC,
180mm f/2.8 AI(S)/AF. Select the wrong ones and you will get some
very harsh OOF effects.
I agree with your comments about Zeiss glass, but to suggest that
Pentax lenses all have good bokeh is, in my opinion, an overly
sweeping generalisation about Pentax glass. There are some Pentax
lenses with good sharpness and good bokeh, but this is often a result
of sacrificing other optical qualities that are perhaps equally
important/desirable.
Tony
From: "Jeremy" jeremy@no-spam-thanks.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Date: Tue, 17 Jun 2003
I said (way at the top
> of this post) "most" not "all" Pentax lenses have great bokeh :-). My friend's
> new version of the 28-105 (Pentax design, I believe, not Tamron) has much
> better sharpness but not as pleasing bokeh as the 28-70/4 (previous lens he
> had). Such is the price of "progress"... ;-)
My recollection is that, back in the Super-Takumar days, when Pentax was
competing with Zeiss in earnest, they were probably the only other lens
manufacturer other than Zeiss that cemented elements 4 & 5 of the normal
lenses, rather than just grinding those surfaces flat and not using cement.
Pentax came closest to manufacturing lenses using the original Planar
formula. The cost was higher, and they were reputed to have sold every
normal lens at a loss.
One of the effects of cementing those two elements was that the sharpness
was reduced slightly at infinity, but the bokeh was purported to have been
much more pleasing. Never having shot using a Zeiss lens, I cannot offer
any personally -verified findings on this. Zeiss continues to allege in
their sales literature that their lenses have the most pleasing bokeh--but
that is obviously a subjective issue.
Pentax appears to have recognized that the bokeh issue is one feature that
they should continue to pursue. One keeps seeing the word "superb" used
when describing Pentax lens' performance in this NG. That particular word
was one that Honeywell exploited in their marketing literature in the
Spotmatic days. I can't help but wonder if it has become somehow associated
with all Pentax lenses in the minds of users? Good marketing? Good lenses?
How does one explain how often that particular word is used when describing
Pentax lenses, as opposed to other excellent brands?
Just a thought . . .
From: "JanR" jrosseel@toohottomailto.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Date: Sun, 15 Jun 2003
"Gordon Moat" moat@attglobal.net wrote
> JanR wrote:
> >
> > And further down in this article, the following is stated:
> >
> > "Basically close-range aberration variation is small, but at portrait
> > distances the correction for aberration seems to be slightly insufficient.
> > The insufficiency as far as spherical aberration in particular is what makes
> > defocus background appeared beautiful."
> >
> > And this confirms the original statement that presence of spherical
> > aberration gives good bokeh...
>
> Glad you read the article. It also stated that aberration was more corrected
> than the original version. To me, that means that the original had more
> spherical aberration. So why is it the second version shows better defocus
> areas?
>
> Your statement seems to imply that the more spherical aberration present gives
> better defocus. This is similar to what Bob M. implies in his message. I
> question that, since in the example I provided, reducing the spherical
> aberration improves the defocus rendition. In this case, less is better. Do you
> think the 105 mm is an isolated case, or some other reason for this?
I'll say a few things about it, and then I'll shut up:
* The statement "The insufficiency as far as spherical aberration in
particular is what makes defocus background appeared beautiful" comes from a
Nikon lens engineer, not me. if Nikon engineers state at different places
(this article, the design of the DC lenses) that sperical aberration gives
good bokeh, then who am I, as a non-optical engineer, to doubt their word?
These are people speaking that have designed optics that are amongst the
best ever produced. I'd take their word over "internet wisdom" (almost)
anytime.
* Sperical aberration correction in the focal plane has by itself nothing to
do with how a lens performs out of the focal plane. Brian Caldwell once
wrote some interesting things on this on this group, and showed images of
raytracings on a 50/1.4 from Nikon. From these images, it can be deduced
that how sperical (and maybe other as well) aberrations are corrected
influences bokeh. Or: it does seem that it *how* sperical aberration is
corrected is more important than *how far* it was corrected in the focal
plane. This could explain why a lens that has in general more correction
(the newer 105 versus the older one), still can have better bokeh. Another
explanation is that the more correction for the new 105 only applies when
focused at infinity. The 105 article indeed specifies that the nice bokeh is
obtained "at portrait distances".
* My own conclusion is that complex optical formulas to correct sperical
and other aberrations as far as possible with wide opening lenses and zoom
lenses, typically produces bad bokeh as the light rays are really thrown
around in all kinds of strange ways to make this happen. Just look at the
images that Brian Caldwell provided to understand what I mean. Simpler
designs (fixed focal, few lenses and groups) will probably produce better
bokeh because of their simpler design. I'd say the best lens is the one
where aberrations are corrected as far as possible in a simple way. Enough
correction to make it sharp, not too much not to kill the bokeh rendition.
It seems that the "new" 105 strikes an optimal balance here.
Regards,
JanR
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 16 Jun 2003
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
...
SNIP
I have the Tamron 24-70 3.3-5.6 (sort of the predecessor to the Tamron 24-135).
It supposedly has one aspherical element. Sharpness is good (despite what
others on lens review site might say), lack of distortion wide is excellent.
Flare sucks (lots of milky haze if it even looks crosswise at a light source).
The bokeh on this excellent too. Nice and soft w/ evenly illuminated blur
discs. I have a feeling that aspherics may be only part of the story w/ the new
Leica M wide angles (particularly the 35/1.4 Summilux ASPH I've been hearing
about). It may be possible to use aspherics to optomise sharpness wide open w/o
affecting bokeh, they may not be mutually exclusive, but I have the feeling
that sometimes one (sharpness) is traded for the other (bokeh) regardless of
the use of aspherics. I wish I had more optical knowledge to confirm or deny
this so this is only a hunch. Sorry to hear about the Sigma, aside from the
zoom lens ring binding, it would seem to be a great range/aperture to have in a
zoom. At least the 50 and 75-150 Series E lenses have great bokeh - don't know
about the wider angle E/other Nikon lenses though. I used to shoot the 25-50
AIS but usually either stopped down and or at its widest angle setting, and one
of the shots I took w/ it at or near wide open aperture at its widest angle
seems a poor way to judge this lens as the background is a backlit white
bedsheet and any kind of good/bad bokeh lens could handle that situation ;-).
Most Pentax and Zeiss lenses have great bokeh but that doesn't help you if you
shoot Nikon ;-)
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: "JanR" jrosseel@toohottomailto.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: bokeh, blade count, and DC lenses Re: Why Nikkor 50/1.4 lens?
Date: Mon, 16 Jun 2003
"Gordon Moat" moat@attglobal.net wrote
>
> Thanks Jan. Much appreciated to go in depth a bit more. I prefer this kind of
> incite, and I have found similar parallels in results from simpler construction
> lenses, some of which are very old designs. It almost seems that with lens
> design, there is not much new, and little benefit to many of the more modern
> formulas, despite computerized ray tracing.
The physics are still the same as 100 years ago. What was a good design
then, is a good design now.
The difference nowadays is that it is possible to correct more because of
computers. And I have the impression that some designers really go overboard
with these new toys. I'm quite sure we will see countermovements, and the
Voigtlaender "Classics" series of lenses might be a sign in that direction.
> However, that is not to say improvements have been made. Zoom lenses are
> generally much better than efforts from a few decades ago. There also
seems to
> have been some advances in materials and coatings.
Wide opening zooms is where computers really help. Especially when one wants
to take advantage of asperical elements that are now easier to produce. But
to come back to the subject of bokeh: I think using aspherics might be the
best way to kill bokeh. I have no substance to back this up, but I assume
that aspherics are really good in giving odd raytracing patterns that all
come together well inside the focal plane, but outside of that... I have a
Sigma 24-70/2.8 EX. Nice, sharp lens. But bokeh wise... Yickes. Three (3)
aspherical elements demand their toll, I assume.
It is actually the bokeh performance of this lens that made me look into
this subject a bit closer. Until then, I thought that all this bokeh stuff
was something invented by Leica guys to claim some immeasurable benefits of
their lenses. I now know differently. After printing a picture of my
youngest one at 70mm/2.8, the out-of-focus background almost screamed at me.
Definitely not a good portrait lens, and I am looking more into acquiring
some dirt cheap fixed focals (anyone say E-series Nikons?) to resolve this
issue.
> Unfortunately, the cost
> cutting measures of modern lenses seems to be the prevalent direction fo
> technology, at least at the low end, high volume areas.
Agree, but it's not all dark. There are some nice evolutions in the
higher-end segment. Lenses (especially zooms) with characteristics and
sharpness that one could only dream of until recently.
...
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 06 Jun 2003
Subject: Re: Why Nikkor 50/1.4 lens?
>Subject: Re: Why Nikkor 50/1.4 lens?
>From: brianc1959@aol.com (brian)
>Date: Fri, Jun 6, 2003
>> What is causing this "geometric aperture shape" if the lens is wide open at
>> f/1.4 - some kind of internal vignetting? Something else?
>> TIA
>> Regards,
>> Lewis
>>
>Lewis:
>Not sure if this is the answer, but tangential vignetting will cause
>off-axis defocused highlights to become elliptical even without
>stopping down. from the image center.
>
>Its a pity the 50/1.4 doesn't come with a more circular iris
>diaphragm, because the spherical aberration at f/2.8 would be
>absolutely perfect for great bokeh.
>
>Brian
>www.caldwellphotographic.com
Thanks Brian :-)
I'm assuming you are referring to the Nikon 50/1.4 above when you say its a
pity, but what you are saying still does not make sense to me because I have
used the 50/1.4 Maxxum w/ the circular iris wide open at 1.4 and still get
eliptoids/"footballs" for oof hilights and geometrically cut off other oof
highlights so I don't see how stopping down even a circular paerture would
reduce this phenomenon since it is the cut off of the aperture, even when wide
open which is causing this in the first place. How does/would stopping down in
this case (the case of the Maxxum w/ the 50/1.4 circular aperture lens) have
any effect on eliminating "geometrical distortion" of the oof highlights due
tot he aperture blades, for that matter how would the Nikon 50/1.4 having
circular aperture blades reduce this problem of internal vignetting/geometrical
distortion of oof highlights?, even if the oof highlights should be circular if
Nikon made their lens w/ circular blades, internal vignetting and/or some other
factor would be causing the edges/shapes of the oof highlights to deform/be
cutoff and or eliptoids/"footballs", wouldn't it? If not, then I don't see why
the Minolta I tried w/ circular aperture at wide open (blades out of the way)
would still have this aperture caused? deforming of the oof higlights shapes
into footballs and cut off other shapes for light sources included in frame -
in other words, if not the aperture itself (since the aperture was wide open on
the Maxxum), what could be causing this "tangential vignetting" as you describe
it?
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Why Nikkor 50/1.4 lens?
Date: 7 Jun 2003
...
Hi Lewis:
I'm having a little trouble following your post, so accept my
apologies if my comments below are irrelevant. The "football" shaped
defocused highlights are due solely to vignetting, which is far more
pronounced in the tangential direction than in the sagittal direction.
As you stop down, the vignetting decreases or goes away entirely,
thus eliminating the football shape. However, in the case of the
50/1.4 Nikkor the shape of the stopped down iris is a fairly
sharp-pointed heptagon, which is clearly visible in defocused point
images. I say this is a pity, because at f/2.8 this lens has slightly
undercorrected spherical aberration which is perfect for excellent
bokeh. The shape of the iris diaphragm ruins the bokeh to some degree
in this case.
Brian
www.caldwellphotographic.com
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Why Nikkor 50/1.4 lens?
Date: 6 Jun 2003
> What is causing this "geometric aperture shape" if the lens is wide open at
> f/1.4 - some kind of internal vignetting? Something else?
> TIA
> Regards,
> Lewis
Lewis:
Not sure if this is the answer, but tangential vignetting will cause
off-axis defocused highlights to become elliptical even without
stopping down. from the image center.
Its a pity the 50/1.4 doesn't come with a more circular iris
diaphragm, because the spherical aberration at f/2.8 would be
absolutely perfect for great bokeh.
Brian
www.caldwellphotographic.com
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Why Nikkor 50/1.4 lens?
Date: 7 Jun 2003
"Wes J" jansen98@earthlink.net wrote
> "brian" brianc1959@aol.com wrote
>
> >I think its safe to say that all 35mm format f/1.4 lenses have substantial vignetting.
>
> Have you checked out the Zeiss?
I'm assuming you mean the Zeiss 50/1.4, and no I haven't ever checked
one out. But if you have access to the lens you can check it
yourself. In order to avoid vignetting a 50/1.4 Planar would have to
have a front element of about 56mm diameter or greater. Typically,
50/1.4's are designed to just barely pass the axial beam, which
results in a front element clear aperture of around 36-40mm. An
unvignetted 50/1.4 would also have very poor performance unless it
were very large and very complex.
Brian
www.caldwellphotographic.com
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Why Nikkor 50/1.4 lens?
Date: 7 Jun 2003
Gordon Moat moat@attglobal.net wrote
> > Lewis:
> > Not sure if this is the answer, but tangential vignetting will cause
> > off-axis defocused highlights to become elliptical even without
> > stopping down. from the image center.
>
> So if I am getting circular, and not elliptical defocus highlights (at f1.4
> only), is it safe to assume that vignetting is not occurring?
>
The elliptical, or "football" shaped defocused highlights would only
occur off-axis since they are caused by vignetting. On, or near, the
center of the picture the defocused highlights will be circular. I
think its safe to say that all 35mm format f/1.4 lenses have
substantial vignetting.
> > Its a pity the 50/1.4 doesn't come with a more circular iris
> > diaphragm, because the spherical aberration at f/2.8 would be
> > absolutely perfect for great bokeh.
>
> It is circular at f1.4, since the blades are fully retracted. However, point
> light sources, or in some cases just high contrast background lighting, either
> directly in the scene, seem nearly as troublesome as when stopping down. The
> difference is that the shape changes from round to a flat sided geometric shape.
> I do not really think that a more circular set of blades, nor more blades, would
> make much difference, though I am interested in how something like that could
> make any difference.
>
> The other thing you now have me wondering about is f2.8. In practice, I have
> tried to use f2 to produce the smoothest defocus highlights. Your comment seems
> to suggest that f2.8 might provide better results. If you can elaborate, I would
> be very interested in your explanation.
In my experience the 50/1.4 Nikkor has better bokeh at f/2.8 than the
45mm/2.8 GN. The difference is entirely due to the nature of
spherical aberration correction in each lens. Unfortunately, the good
bokeh of the 50/1.4 stopped down to f/2.8 can be upset somewhat by the
shape of the iris diaphragm, depending on the scene.
Here is a longitudinal spherical aberration plot for the 50/1.4 Nikkor
which helps to explain some of the behavior:
http://caldwellphotographic.com/50mm14LongitudinalAberration.jpg
Up to about f/2.8 the spherical aberration is undercorrected, which
gives you nice background bokeh. However, by the time you get to f/2
there is an over-corrected component which will cause a bright ring in
the defocused background highlights. So, for the smoothest defocused
background I would use this lens at f/2.8.
Because of this complex spherical aberration correction, it turns out
that neither the background nor the foreground defocused highlights
can be smooth when the lens is set wide open to f/1.4. This is shown
by this spot diagram:
http://caldwellphotographic.com/50mm14defocusedspotdiagrams.jpg
Another way to visualize what is going on is to look at a ray trace
near the focal point to see how the rays are bunching up in the
foreground and background areas:
http://caldwellphotographic.com/50mm14caustic.jpg
Hope this helps.
Brian
www.caldwellphotographic.com
From: Christoph Breitkopf chris@chr-breitkopf.de
Newsgroups: rec.photo.equipment.35mm
Subject: Re: L - "Football Bokeh" Was: Re: Why Nikkor 50/1.4 lens?
Date: 12 Jun 2003
Hello Lewis,
contaxman@aol.comnospam (Lewis Lang) writes:
> Thanks Brian for explaining it to me. So I take it that the body of the lens
> itself when wide open, not any aperture blades, is what is causing the oof coc
> shape cut off elliptods/"fottballs"?
The camera, too. Often the flipped-up mirror still cuts off some
light at large apertures.
> Are all f/1.4 or larger lenses really f/2 or f/2.8 (regardless of circular
> apertures or not) if someone wants to elliminate "football bokeh"?
Somewhere below 2. In theory, manufacturers with larger (and closer
to the film plane) mounts, like Canon EOF are at an advantage
here. I don't know how this is in practice, though.
Regards,
Chris
From: Roger leica35@yahoo.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Why Nikkor 50/1.4 lens?
Date: Wed, 04 Jun 2003
Manh Le manhlhle@austin.rr.com wrote:
>The concensus in this newsgroup, reviews at other web site, and my own
>unpleasant experiences with the Nikkor 50/1.4 lens seem to be well
>aligned, especially at 1.4
>
>I did shoot a roll of film at 1.4 and have promised myself never to do
>it again. However, I do enjoy the brightness of the 50/1.4 lens but
>apart from this I can't find any other advantages over the 50/1.8.
I don't hesitate to use my f1.4 lens at f2 and above. I do shoot a lot
of available light and I do like very much the focusing ease of the
f1.4 at full aperture. If I think I'm going to push the limits and
f1.4 will ease the situation then I use the f1.4 aperture.
As an aside to this discussion, my Nikkor f1.4 is very much different
from my Leica f1.4 and I look for ways to use the Leica lens at full
aperture. They give very different results.
Another side bar is that over the years the films have improved
greatly and many people now shoot ISO 400 film routinely where in
years past ISO 25/50 film was more of a choice. That also makes a big
difference in how you use your lenses or tripods or both. At ISO 50
you have a lot fewer apertures to choose from and if f1.4 is available
it may be the ONLY way. That doesn't so much effect the quality of the
lens, but how people think about what is necessary about maximum
aperture. Some of us remember the times when ISO was lower and mirror
bounce was more significant. A f1.4 option was more of an issue. Now
with quieter mirrors, faster films and focus assist some of that f1.4
mystique could be relegated to just that, mystique. It's all in what
you need and some of the newer advances in camera and film technology
have lessened the need for some for f1.4.
In earlier threads I've mentioned that I have and use several 50's. In
terms of ease of use, I've gravitated to the 50mm f1.8 AI (the one
with the recessed lens element). This is a quality lens that more than
anything for me is adequately convenient. The recessed element is
protected, it doesn't need a shade as much as some of the other 50's.
It's compact and a delight to manually focus. I like the results and
it's compact. It is my street lens and can go in and out of my bag
without a filter, shade or cap for protection. The blend of
convenience and results make it my favorite. That's why I say it's
adequate - for my needs in that situation - and as a result I rarely
mount any of my other lenses, either MF or AF, regardless of body.
Careful testing may indicate that another Nikkor is better, the Leica
certainly is in the way I use it, but for Nikon use, it is my choice.
In terms of sheer performance, there are noticeable differences, but
IME we are talking about slight differences in lenses that overall are
quite similar in performance. The notable differences that I've seen
in my usage are in the corners at the wider apertures. If that is
going to be a noticeable segment of your photographs in this focal
length, then it's worth considering the finer differences in these
lenses.
Regards,
Roger
>Is there any other photographical application that the 50/1.4 have
>advantages over the 50/1.8?
>
>Manh
From: Christoph Breitkopf chris@chr-breitkopf.de
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Good 35mm and 6x7 film vs. digital comparison
Date: 03 Jun 2003
Gordon Moat moat@attglobal.net writes:
> It also seems that changes have occurred, even at Leica. Around the time of the M6
> introduction, that family of lenses started to take on a higher contrast
> appearance in the final images. I am not sure why that direction was taken, but
> many examples that I have seen from newer Leica lenses show less of the smooth
> tonality of the older lenses. The few designs that have not changed give largely
> the same results as older gear. I prefer the look created with the older lenses,
> though some consider the results to be softer.
Some information about the changes in the M-lenses are in
this very interesting (even for non-Leica people such as me)
article by Erwin Puts:
http://www.leica-camera.com/imperia/md/content/pdf/msystem/49.pdf
He says among other things, that the bokeh has somewhat suffered
for better sharpness.
(Also available in German:
http://www.leica-camera.com/imperia/md/content/pdf/msystem/48.pdf)
Regards,
Chris
Date: Mon, 02 Jun 2003
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Good 35mm and 6x7 film vs. digital comparison
Hello Lewis,
> >Lewis:
> >About the "tonality" thing: doesn't this refer to a smooth transition
> >from one tone to another? I would think that it is directly related
> >to noise/grain. If you have grain then you obviously disrupt the
> >smooth transition from one tone to another. For this reason I
> >consider high quality digital images to have far superior tonality to
> >film images. Differences due to the shape of the exposure/density
> >curves are another matter altogether.
> >
> >Brian
> >www.caldwellphotographic.com
>
> Brian:
>
> There's more to it than just the transition being smooth, though this helps/is
> pleasant to the eye, tonaility is (at least to me, anyways) about how many
> subtle tones are resolved w/i that smooth transition that gives an image
> richness/clarity. Tonality has more to it than just whether grain interferes w/
> tonal transitions or not, its about the amount of semi-tones (or semi-hues)
> recorded going from one tone (or one hue) to another and for this (more
> tonality) you need more info, regardless of graininess, though graininess can
> cause the eye to lock onto it rather than whatever degree of tonality is there
> in a picture.
Basically, I agree with how you stated this. I do find that colour quality, and
tonality are more important issues for my imagery.
> To broach what I believe is an almost taboo subject here (the
> superiority of most Leica lenses over most other brands ;-)), what gives Leica
> lenses their larger format look (despite whatever grain is or isn't in a 35mm
> image) is the fact that they tend to discriminate fine shadings of hues (my
> main experience is using them for color though I've done some B&W Leica images
> too) better than most lenses which gives them an openess and clearness (tied
> also w/ beautiful gradual bokeh transitions from in focus areas to out of focus
> areas that still retain detail) most lenses lack.
I will also broach this subject a bit too. Older Leica lenses of the early M era
had a smooth look to their resulting images. This was noticeably different than
Nikon lenses of the same era, and some other japanese brands. The difference
seemed to be that Nikon (et al) biased towards contrast, with the intention of
gaining some sharpness increase when images were printed in new or magazine form.
Leica on the other hand tended towards getting nicer chemical prints, with a less
harsh look. Considering that both types of lenses were often used for hand held
photography, it is not worth to compare resolution. Anyway, these are aspects that
I have heard quite often about the Leica "look".
It also seems that changes have occurred, even at Leica. Around the time of the M6
introduction, that family of lenses started to take on a higher contrast
appearance in the final images. I am not sure why that direction was taken, but
many examples that I have seen from newer Leica lenses show less of the smooth
tonality of the older lenses. The few designs that have not changed give largely
the same results as older gear. I prefer the look created with the older lenses,
though some consider the results to be softer.
The old bias of Nikon and others was directed at the printed image, not chemical
photo prints. While there were some designs that gave a smoother result, many of
the designs were contrast biased. My comments are based upon observation of actual
printed pieces. With the Nikon gear, I tend to prefer that contrasty look of the
older prime lenses. Much of the newer gear gives softer renditions, especially the
zoom choices, and it seems that there is a little less contrast, though perhaps
not so intentional.
To further this taboo aspect, I feel that there are some lens design that cross
the boundary of contrast or smooth tonality. It has been possible to fool many
people into believing a 35 mm image was actually medium format, or to have people
thinking the camera used was a Leica. I think this is largely because newer films
are so good, that they greatly compliment many different lenses.
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From minolta mailing list:
Date: Fri, 06 Jun 2003
From: "Paul Brecht" pariht@pacbell.net
Subject: Re: Bokeh ?
I don't think that that's necessarily the best way to judge bokeh...
Look at a typical shot (well, that could be anything I suppose) I'd
say different types of shots. Try this:
Studio Setting:
set up a table of a few things & take many shots. Make sure that you
have a strong backlight. At all relevant apertures, shoot 3 shots: 1.
near focus, 2. correct focus & 3. distant focus.
example:
f/2.8 close/normal/distant
f/3.5 close/normal/distant
etc., etc...
I'm not implying that you focus all the way close or at infinity, but
close to...
When choosing close/far focus, go all the way & back off a bit...
Scenic:
Do the same thing at all relevant apertures shooting 3 shots each.
Do the same with portraits or whatever else you can test on...
Report your results...
Paul (dubbed a bokeholic by B. Wrainey)
--- In Minolta@yahoogroups.com, "annapoal" greenealan@a... wrote:
> I didn't mean to get folks upset. My quick way to measure for bokeh
> is focusing through tree leave at a light source. If the light
> between the leaves goes smoothly out of focus without a center, a
> dark ring next or a halo it is said to have, sorry, good bokeh. If
> instead the light takes on the look of a dandylion that has gone to
> seed with a center, dark ring around the center, and lastly a halo
> ouside of that then it is said to have bad bokeh. Looks like smoe
> sort of ball. I do feel that bad bokeh does detract from the image.
> Sorry again, I do love my af 70-210 f/4 but it does not have good
> bokeh. Just checked it to be sure. As for g and other minolta lens
> check the minolta lens chart and you will find many have had changes
> to try to improve bokeh which is primarily a function of the lens
> diaphram. Love my minolta lens but not their bokeh and work to
> minimize bad bokeh in shots. Have actually used a 40-50 year old
> asahi 50mm f/2 with an 11 blade diaphram when bokeh was really
> important. That old lens does not match the color or contrast of the
> well coated Minolta lens but it has world class bokeh. Has anyone had
> experience with the maxxum 7 feature to improve bokeh? How did it
> work?
From: "Q.G. de Bakker" qnu@tiscali.nl
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Date: Tue, 15 Jul 2003
Steve Hamley wrote:
> I think this is true to some extent. While most of us can agree that
> the double-image highlights constitute "bad" bokeh, it clearly (by
> response to many threads in many places) bothers some people a lot
> more than others. Personally, when I view a picture with bad bokeh, I
> feel like I'm looking at it with my eyes crossed.
Indeed. That's what made me confident about not getting consensus.
I have one of those lenses that many people seem to like a lot for its
"good" bokeh (f/2 110 mm Planar), yet i always notice those double-image
out-of-focus parts. Those appear to be enveloped in slightly larger sized,
rather vague copies of themselves, which are clearer, more distinct towards
their edges.
I generally don't pay much attention to "bokeh", but if pressed i would say
it is "bad bokeh". I have had abuse hurled at me from people absolutely
loving this lens and its "bokeh" for mentioning that (having bought the lens
because people wax lyrical about it, so i just had to get one and see for
myself) i fail to see what would be so special about it. ;-)
From: Joe Polizzi [polizzi@westbend.net]
Sent: Mon 7/7/2003
To: Lenses@topica.com
Subject: RE: [LENSES] Price in Germany, was Second Hand 35/1.2!
Hey - does anyone know about the characteristic 'look' of these lenses?
What I'd like to know is; if price wasn't an issue, which lens would be
better for what. I mean - can I assume that the Ultron is a sharper
lens than the Nokton, just because of the difficulty correcting such big
glass? Might the Nok be a better people lens - even stopped-down? Is
the Nok maybe a lower contrast lens than the Ultron? How's the bokeh
on'em?
I should Mention that I just recieved a new Ultron last week. Oh boy!
Bytheway: price was neccesarily the major factor in my decision to buy
the 1.7 over the 1.2!
I'd appreciate any info on what I can expect with the Ultron. Will the
Ultron flare as bad as my 50mm Nokton? I get some wildly flared-out
frames with that thing!
Speaking of flare: Did you see Roger's 'flare tests' of that 43mm Pentax
lens? Impressive - but that SMC coating has long been one of the best,
right? I remember seeing a table of flare mesurements on lenses (was it
just third-party lenses?) done by a photo mag back in the 70s - many
lenses compared, and an SMC normal came up on top for lowest flare. I'd
like to know how to perform quantitative flare tests!
These are Roger's shots - he posted them on CVUG:
http://www.pgallery.net/rogerama/image-38850.html
http://www.pgallery.net/rogerama/image-38851.html
http://www.pgallery.net/rogerama/image-38852.html
http://www.pgallery.net/rogerama/image-38853.html
http://www.pgallery.net/rogerama/image-39173.html
Doug Miles wrote:
>
> I approach this decision by asking myself how often I'm shooting wide
> open with my current lens; how often I wish to grab another f-stop of
> light or throw fore/background that much more out of focus. Now f/1.2
> sounds great for a 35, and I want one just because it's there! But in
> sober reflection I almost never shoot wide open except with those slower
>
> f/3.5-f/4.5 wide angles. I guess I could TRY shooting the old Summicron
> 35 more wide open to see if I could USE even more wide open!
>
> Doug
>
> peter@despammed.com wrote:
>
> > If getting it means that you have to sell (or can't also buy) the
> > 35/1.7 (or similar), I wonder how many photos you'd *lose* in the
> > year, because you couldn't be bothered to lug this thing around.
From: Michael Briggs MichaelBriggs@EarthLink.net
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Fujinon 250 SF
Date: Fri, 18 Jul 2003
Xosni wrote:
>
> I don't understand the exact practical effect of the disks. How does
> the lens perfom with and without them? Wide open and stopped down. Do
> the disk effect the actual f-stop?
Modern soft-focus lenses (Imagon and Fuji-SF) are based on spherical
abberation. The degree of softness is controlled by the balence
between light from the outer portions of the lens vs the center of the
lens. The focal length for the outer portions of the lens is different
than the focal length for the center rays. If you focus stopped down
and then open up, you will superimpose a out-of-focus image on the sharp
image.
Anything that changes the ratio between light rays from the outer
portions of the lens and the inner portions will change this effect.
This means either using a disk or stopping down.
Obviously inserting a disk reduces the light transmitted. f-stop is
not a fully accurate concept since the effects on depth-of-field may be
somewhat different than on most lenses. These lenses have three f-stop
scales, one for use without any disk (grid), and one each for the two
disks (grids).
A lot of this is explained in the brochure that ships with new Fuji LF
lenses. Unfortunately brand new Fuji lenses seem to have the brochure
in Japanese only. Even the older version in English is sometimes a bit
confusing, I suspect from translation deficiencies.
From the brochure:
"The spherical aberration of these lenses has been retained to enable
them to produce the desired effects. Thorough acquaintance with the
effects they will produce is, therefore, necessary in order to make the
most of what they can offer, because the picture will turn out
differently depending on how they are focused or defocused, as well as
on the aperture used and on whether or not the picture is taken with the
grid on or off and the type of grid used."
> How does it perform with color film?
Plain spherical abberation isn't dependent on wavelength (color). The
Fuji brochure states that the lens is "thoroughly corrected for color
aberration". So it should work fine on color film.
> And how sharp can it get? Could it be used as a normal lens?
The more you stop down, the sharper it gets. I haven't tried one, but
Fuji states in the brochure "The softness gradually tails off as the
aperture is closed down until at f/22 they are no different from any
other lens." They might not be quite as sharp over the whole field as
a current top-of-the-line general purpose lens, but they should be
acceptably sharp for some purposes. They are really special purpose
lenses. Before using as a primary lens, you might want to compare to a
more standard lens.
--Michael
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Date: Wed, 16 Jul 2003
Bob Monaghan wrote:
>
> my main interest is in finding good bokeh lenses for portraiture, and in
> avoiding bad bokeh lenses in general ;-) so a test of wide open lens
> performance with both central and edge highlights at portraiture distances
> would be most useful.
>
Depends on the application. For portraits a harsh bokeh lens is bad news but
for landscapes I've found harsh bokeh can fake the viewer into seeing
slightly more DOF that actually exists at normal viewing distances. Of
course the DOF isn't actually more but the slightly out of focus parts of a
scene, especially something like grass or pinestraw, can appear to be 'in
focus' due to the harsh bokeh where a smooth bokeh lens would be obviously
blurred. I've discovered the soviet 250mm telear works great for this as
the harsh bokeh, which is still there at small f stops, draws in the
foreground where something like the 300mm sonar would render it obviously
blurred. It seems some of the sharper lenses have harsher bokeh while some
of lenses with really nice bokeh don't test as extra sharp?
--
Stacey
From: Struan Gray struan.gray@sljus.lu.se
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Date: 16 Jul 2003
Bob Monaghan, rmonagha@engr.smu.edu writes:
> I am not saying that bokeh is simply under or over corrected
> spherical aberrations (other factors including diffraction disk shape
> may have an impact in some situations - though not wide open ;-). But
> the major contributor in most lenses is probably spherical abs, based on
> lens designer comments, reported tests (photo tech may/june 1997..) etc.
I think you are perhaps being misled by the fact that spherical
aberration dominates in lenses that have been well-corrected for other
aberrations. Also, that portrait lenses like the new Cooke LF or the
Imagons use carefully controlled spherical aberration to create a soft
focus look. If you're looking to explain bokeh in general, particularly
bad bokeh, other aberrations become as important if not more so.
Really ugly bokeh can be caused by asymmetric aberrations such as
coma and astigmatism. Take a consumer zoom or cheap telephoto lens and
take a photo of something at closest focus surrounded by a detail-rich
background such as grass foliage or gravel. Marvel at the sickening
whirlpool effect you end up with. It is no accident that the first
great brand names in historic lenses were those that eliminated
astigmatism.
Optics design software lets you plot 'spot diagrams', which show
nicely how a point source highlight will spread at given positions,
apertures and focal distances. In an ideal world a lens data sheet
would include these, but you just have to look at the nonsense talked
about MTF curves to see why manufacturers don't do this. If you buy a
custom lens the designer will usually include them when quoting.
I applaud your efforts, but my own survey of bokeh shows that
general prescriptions are useless. If you succeed in doing a worthwhile
survey, you will essentially end up with a database of spot diagrams. I
have a Pentax 43 mm lens for 35 mm that makes lovely head and shoulders
portraits of my toddlers wide open at minimum focus distance - the look
is almost as good as LF if you ignore grain - but you have to be careful
to avoid bright highlights in the background as these end up with edges
that are a tad too hard. My Kowa 150 makes similarly gorgeous low DOF
portraits in MF. It somehow avoids the nasty background effect, but
foreground details can look a bit odd.
Struan
Date: Tue, 15 Jul 2003
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Bob Monaghan wrote:
> yes, the diopter lenses (+) would add some spherical aberration, their
> main flaw, to a regular lens setup. Similarly, teleconverters often add a
> bit of spherical aberration in addition to "magnifying" existing lens
> flaws and aberrations. So that may be another trick to get more
> aberrations rather than less ;-) ditto extension tubes, acting to project
> the image, and so magnify it and with magnification, magnify its flaws too
I learned the technique from a portrait photographer, while I was in college.
It is not something I use often, but it really changes almost any lens. This
is one true path to cheap and easy good defocus highlights. Extension tubes
do not seem that popular, and are sometimes a bargain used.
> I'm not sure a simple background with some highlights (I'm thinking along
> the lines of Xmas tree lights in black cardboard behind a subject?) could
> not provide a zone of highlights to evaluate, and a regular background
> too at the same time in a slightly offset position. Ideally, I'd like to
> evaluate bokeh with as few shots as possible. A foreground element could
> do the same, so we could have:
>
> -------- background with lights showing thru the holes for highlights
> subject - at portrait distances, could be a clothing dummy or ??
> -------- foreground, again with lights showing thru holes
> [] camera at set portrait distance...
I would think that one or two table lamps should be enough. With the really
small lights, it would be tougher to see differences on JPEG sized web
displayed images.
> the points about fast lenses is interesting; some of the best bokeh seems
> to be associated with the faster lenses, like norita 80mm f/2, hasselblad
> 110mm f/2, Bronica S2/EC Komura 135mm f/2.3 and so on.
More spherical aberration? Perhaps since more in each image can be out of
focus, those areas of the image from these lenses, becomes more noticeable.
> I also suspect you are right, in that many older simpler design folder etc
> lenses may have more undercorrected spherical aberrations, so be good for
> portraiture, if not sharp enough for copying or similar work ;-)
They are very flattering for portrait work. Some other pros that have seen
some of my AGFA shots comment on the softness, yet good resolution of the
images. One large contact sheet of 6x4.5 images has been used as a display
item at one of the labs I use for my work.
> I am also working on a "flare" test, using similar in and out of subject
> space lights and a black background to provide flare response...
Candles are another good source, or shiny glass or metal object in the
background (chrome?).
> I doubt that we can be exact, but we probably don't have to be; it is
> enough to note a lens is noticeably distorted (>1.5%), modestly distorted
> (1% or so), or low distortion (below 1/2% or so). The differences between
> these values is fairly subtle, and not so significant to most users.
Agreed.
> Ditto bokeh. We may be able to say it is "good" at our typical portraiture
> setup (i.e., I'm ducking the issue of closeups ;-) wide open, down to some
> given stop which will vary with each lens (as s.a. improves..).
I still think the close-up issue will need to be addressed. Some lenses do
work better than others at close distances, and they should not be easily
dismissed when they do not perform as well at slightly greater distances.
Subjective, objective, and thorough.
> In any case, I've posted the anecdotal evidence at
> http://medfmt.8k.com/mf/bestbokeh.html from mf/bokeh.html pages notes
> since many of these folks are probably known to frequent USENET readers,
> they can use reputations to form some weights on expressed opinions ;-)
I can see a few I disagree on, though it is a good start. Some of the ones I
disagree on perform very well without background highlights in the scene.
> again, bokeh seems to be more of a concern to 35mm shooters, perhaps due
> to the larger number of lens choices. It makes a difference if you buy the
> 35mm f/1.4 nikkor for its highly reputed bokeh rather than the slower f/2
> or f/2.8 or f/3.5 nikkor versions, for example.
Since you do not have it listed, the Nikkor 35 mm f2.8 shift lens provides
very smooth defocus highlights when used wide open and unshifted. There is
also a separation quality to the defocus that often gives a 3D look to the
final images. Since I am not well known, I should mention that David Reuther
also praises this lens, as a few others have done on line.
> In MF, we don't have so
> many speed choices usually (eg, norita 80mm f/2 and f/2.8, bronica EC/S2
> f/2.8 or f/2.4 normal lenses nikkor and CZJ etc.).
Really only a handful of f2 choices, though some good f4 choices do quite
well with defocus rendition. One observation is that the Gauss based designs
seem to do well in this regard. I believe that is a very old design basis to
start with for a lens design.
> still, I think the anecdotal evidence, for all its faults, may be worth
> collecting and soliciting, as a way to highlight some possible better lens
> choices for those of us who value bokeh more than the average user?...
I gladly volunteer the two images I presented . . . though only if you can
guess something about which lens was used. ;-) It is fairly famous in the
35 mm world, and in some opinions legendary.
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: CaptChuckLZ@yahoo.com (Captain Chuck)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Polaroid 110a/b/pathfinder converted to 120roll film
Date: 13 Jul 2003
The overlooked point is that the "amateur" Polaroid's lenses-excluding
the really cheap ones' plastic ones-are often _exactly_ the lens for
portraiture. They have a soft focus quality that is absolutely classic
and I have seen the Pathfinder front standard mounted on a 35mm
extension tube with great success.
The rollfilm cameras were overbuilt and could last a very, very long
while. What isn't generaly realized is that for all the old 'roids at
garage sales, Polaroid themselves bought back and destroyed enormous
numbers of these cameras, which were often very expensive new
From: sahamley@netscape.net (Steve Hamley)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Date: 14 Jul 2003
Bill,
There is an article on MTF charts at the Luminous Landscape that tends
to support this view.
http://www.luminous-landscape.com/tutorials/understanding-series/understanding-mtf.shtml
I think most older lenses that are generally acknowledged to have good
Bokeh seem to be triplets or modified triplets (Heliar, some Leica?)
Thanks!
Steve
"Billl Siler" wsiler02@midsouth.rr.com wrote
> See the comments on bokeh in the article "Understanding MTF" at link
> http://www.luminous-landscape.com/tutorials/understanding-series/understanding-mtf.shtml.
> According to this article,
> "One of the areas of image quality that MTF can help determine is bokeh.
> This is a Japanese word used to describe the manner in which a lens
> reproduces the out of focus areas of an image. Some lenses are harsh in this
> regard, while others produce a much more pleasing out of focus image. This
> is where the meridonial and sagital lines come in, and as you'll recall are
> represented by the dotted and dashed lines. The closer these lines are to
> each other the more pleasing the bokeh of the lens. Fascinating, huh?"
>
> If this is true, maybe bokeh could be quantified based on a difference in
> the values of the meridonial and sagital MTF components.
>
> Bill
...
From: "Billl Siler" wsiler02@midsouth.rr.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Date: Thu, 10 Jul 2003
See the comments on bokeh in the article "Understanding MTF" at link
http://www.luminous-landscape.com/tutorials/understanding-series/understanding-mtf.shtml.
According to this article,
"One of the areas of image quality that MTF can help determine is bokeh.
This is a Japanese word used to describe the manner in which a lens
reproduces the out of focus areas of an image. Some lenses are harsh in this
regard, while others produce a much more pleasing out of focus image. This
is where the meridonial and sagital lines come in, and as you'll recall are
represented by the dotted and dashed lines. The closer these lines are to
each other the more pleasing the bokeh of the lens. Fascinating, huh?"
If this is true, maybe bokeh could be quantified based on a difference in
the values of the meridonial and sagital MTF components.
Bill
...
From: rcochran@lanset.com (Richard Cochran)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Date: 9 Jul 2003
...
I'm sure it can be defined and measured, but I'm not so convinced
you can meaningfully quantify it down to a single scalar number,
or even a small vector. Maybe I'm wrong, though.
A starting point is to note how a lens renders a pinpoint of
light that's outside of the plane of sharp focus. You can come
up with a curve that describes the intensity versus distance from
the center of the image of the out of focus point. "Good" bokeh
will have the intensity decreasing relatively smoothly as you go
away from the center, "neutral" bokeh will have the intensity
flat out to a certain point, and suddenly drop off to near zero,
and "bad" bokeh will have its highest intensity somewhere away
from the center of the image of the point. So as a first cut,
you might like to create this curve for each lens, focusing
the lens at some standard nearby distance, while photographing
a star (real or simulated) pinpoint source of light at infinity.
But it's worth noting that spherical aberration manipulation can
produce "good" bokeh in front of the plane of sharp focus, or
behind the plane of sharp focus, but not both simultanously.
Whereas the donut shaped apertures of mirror lenses can produce
bad bokeh in front and behind simultaneously. And I could
hypothesize a perfectly corrected neutral lens with a
graduated ND filter in place of the standard aperture
diaphragm, with the ND filter designed to produce arbitrarily
"good" bokeh both in front and behind the plane of focus.
Lenses with significant coma or astigmatism may produce "good"
bokeh in the center of the frame, but can produce distractingly
ugly bokeh off-axis.
I'm not sure whether the details of bokeh vary with focused
distance, as well. I could easily believe that zoom lenses
could have varying bokeh at different focal lengths.
If you measure the image of an out-of-focus pinhole,
there's one dependent variable: relative intensity of light,
with many independent variables: distance from center point of
image of pinpoint source, focused distance of lens, distance
of pinpoint source of light in front or behind plane of sharp
focus, distance of pinpoint source of light from center of
lens axis, selected aperture, zoom setting (for zoom lenses),
and perhaps other factors I'm not thinking of. You could
probably define a scalar function of five or six variables
that could precisely quantify bokeh in all its detail, but
presenting that function in a meaningful way would be
challenging, to say the least. And I'm not sure that
you can reduce the number of variables you consider
very much without leaving out something that will be
important, at least in some special case of lens designs.
It's similar to describing the "sharpness" of a lens, but
perhaps even more complex. Is lens "A" sharper than lens
"B"? That's a simple question to ask, but a difficult
one to answer. Sometimes, it's pretty clear that one lens
is sharper than the other, but when lenses are relatively
well matched, you have to say things like "at what
aperture?" "at what contrast level?" "at what spatial
frequency?" "How far from the lens axis?" "at what
focused distance?" We haven't managed to quantify such
an intuitivly understandable concept as sharpness down
to a single number, and I'm afraid bokeh will, if
anything, be more complex.
That doesn't make it unreal or unmeasureable, just
exceedingly difficult to measure and present in an
quantifiable, understandable, and meaningful way.
--Rich
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: can bokeh be quantified? described?
Date: Mon, 07 Jul 2003
Bob Monaghan wrote:
> I do think it would be an interesting project for the various camera and
> lens brand lists (e.g., Kiev88, PentaxMF..) to see if a consensus can be
> reached on which lenses within a particular line are consistently rated as
> having good bokeh, and perhaps even more useful, really, really BAD bokeh
> ;-) ;-)
In the kiev/P6 line the f2.8 180mm sonar has probably the prettiest bokeh
I've seen from any camera lens. The 80mm biometar's is nice as well. The
120 biometar isn't quite as good but isn't bad. I've seen some shots from
the arsat 150 f2.8 and while not as nice as the sonar, it's not bad either.
The 80mm arsat, the 120mm vega and the 250mm telear have some pretty nasty
looking bokeh but are contrasty and sharp! Bet they's beat the zeiss
lenses on a MTF test. :-)
--
Stacey
From rangefinder mailing list:
Date: Thu, 11 Sep 2003
From: brianvsweeney@comcast.net
Cc: lenses@topica.com
Subject: Re: [RF List] Not Bokeh, its just like surveillance satellite orbits.
1: You are right, this discussion should be on the Lenses list.
2: I have been posting shots taken with my RF cameras and Lenses (ie having
fun using them) so I put them here.
3: I have been exploiting the Bokeh discussion (flame-war) as an excuse to
shoot at maximum aperture to find out what those lenses would do.
http://mywebpages.comcast.net/brianvsweeney/c7nikkorb.JPG
Nikkor 5cm F1.4 at F5.6
http://mywebpages.comcast.net/brianvsweeney/c7nikkor5_2a.JPG
If "Bokeh" is an optical property of a lens, we should be able to
characterize it. If "bad Bokeh" is just an opinion of a cluttered background
in a picture, it will always lead to a debate.
If the optical properties of a particular lens cause it to handle the out-of-
focus regions of a scene in a form that is distracting "or unnatural" that is
something that a ray-tracing program would indicate.
Optical Properties that "may" lead to a distracting background:
1: the intensity profile across the circle of confusion: Gaussian, tends to
blend points sources into each other with low-frequency. Inverse Gaussian
(platelet), tends to blend point sources into each other and
create "bright" "higher frequency" artifacts as the out-of-focus point sources
add together across the image.
2: The "trajectory" that the circle of confusion makes as it falls onto the
film plane. If all of the circles fell flat onto the film plane, an array of
out-of-focus point sources across the image would all look like circles. If
the trajectory is at an angle, they will look like ellipses.
3. Change in trajectory, angle of entry, as a function of distance from the
center of the image, the "eccentricity" of the ellipses change. I think that
is what produces the "swirly" effect of the Summarit. If I want a "dreamy"
(hallucinatory?) quality in my picture, I know what lens to use now.
If I understand the concept of Bokeh, and I may not, A perfect Bokeh lens
would 1: Have a Gaussian Distribution of the intensity profile of the out-of-
focus regions. 2: Have a perpendicular trajectory onto the film plane. 3: the
trajectory would always be perpendicular and not change with distance from the
center of the image.
This goes beyond what most lenses are designed for: producing a sharp and
undistorted image when focussed. Im am guessing that Telephoto lenses are as
close to my "perfect Bokeh" as a natural fall-out of their design.
Brian Sweeney
Initials BS
Coincidence? Not according to my Dad.
> Let's start calling the character of out-of-focus background areas
> "sfumato"... I mean, surely I can't be the only one who is tired of
> bokeh, bokeh, bokeh...
>
> Seriously though, folks, the Lenses list on Topica.com is the place for
> discussing lens characteristics, especially when they can't easily be
> quantified.
>
> Roger
>
> Work: www.adex-japan.com
> Play: rogerama at www.pgallery.net & www.fujirangefinder.com
From: Brian Sweeney [brianvsweeney@comcast.net]
Sent: Fri 9/12/2003
To: Lenses@topica.com
Subject: [LENSES] From "Practical Optics" and "Photographic Lenses"
This is from a book by KB Johnson: It talks about over and under correction of
spherical abberation"
http://mywebpages.comcast.net/brianvsweeney/spherical_correction.JPG
Astigmatism: Swirlies?
http://mywebpages.comcast.net/brianvsweeney/astigmatism.JPG
And what I described as the CoC being out of the film plane.
http://mywebpages.comcast.net/brianvsweeney/petzval.JPG
Could a Combination of the three for out-of-focus points be responsible? If so
is it possible to come up with metrics (acceptable size for circle of
confusion and an equation to relate it to F-Stop) like we have for depth-of-
field to describe them?
Brian
From: Brian Sweeney [brianvsweeney@comcast.net]
Sent: Thu 9/11/2003
To: Lenses@topica.com
Subject: RE: [LENSES] [RF List] Not Bokeh, its just like surveillance satellite orbits.
BIG WHOOPS ALL! That is what I get for typing Emails of formulas from memory,
of which I have about a 30 second MTBF. All of this talk of Bokeh has led to a
lack of focus for me.
>My perfect "bokeh" lens would have (Cos(x)**4)
>where x=pi/2 at the center and 0 at the circumference. Two equal point sources
>separated by the diameter of the circle of confusion add up quite nicely.
WHOA! That formula is for My perfectly BAD convolution function! Zero at the
center and 1.0 at the edges!
The GOOD one is:
(Sin(x)**4)where x=pi/2 at the center and 0 at the circumference. Two equal
point sources separated by the diameter of the circle of confusion add up quite
nicely. Same as (Cos(x)**4)where x=0 at the center and pi/2 at the
Circumference, which is what I computed then forgot on my way to a different
computer attached to the Net! A thirty second walk...
All would have to be normalized to 1.
The fourth power does not affect the edges of the sine and cosine, it serves to
make the curves steeper. The fourth power works out to make the two adjacent
circles of confusion meld nicely without causing an additive bright spot. All
of this good/bad is Subjective.
Brian
>My perfect "bokeh" lens would have (Cos(x)**4)
> where x=pi/2 at the center and 0 at the circumference. Two equal point sources
> separated by the diameter of the circle of confusion add up quite nicely.
From: Bob Blakley [blakley@us.ibm.com]
Sent: Tue 9/16/2003
To: Lenses@topica.com
Subject: RE: [LENSES] Please say "when" if you have enough...
brianvsweeney@comcast.net wrote:
> So the question stands: is the background clutter structured and
> providing the
> dominant affect, or is it the over/under corrected abberations of the
> lens.
> One easy test for me to do is "paint" a grid of spaced dots across a
> flat
> panel monitor, set focus for infinity, at F1.5, and see what happens. If
> the
> effect is "reciprocal" I should get interesting results.
>
> Closest Focus at F1.5, should be "worst case" for out-of-focus
> http://mywebpages.comcast.net/brianvsweeney/summarit_close1a.JPG
Wow - ugh. If it's not worst-case, it's sure bad enough.
And it gives a really convincing (and disturbing) swirl around
the optical center of the lens. But in this shot and its
enlargement, I *still* can't quite tell if the shapes are
distorted. Your monitor test is the right way to answer the
question, I think (or you could just take a hole punch and
put some round holes in a black posterboard, and photograph
it in front of a bright light - might give you better contrast
& you wouldn't have to worry about monitor refresh rate when
choosing a shutter speed....) Anyway, if you do that experiment,
I'd love to see the results. Maybe I'll try it with my
Summitar....
--bob
From: Brian Sweeney [brianvsweeney@comcast.net]
Sent: Tue 9/16/2003
To: Lenses@topica.com
Subject: RE: [LENSES] Please say "when" if you have enough...
Bob,
My perfect test target would be a grid of point source lights. I am using
the "leaves at infinity with sun-glint" to badly approximate that perfect
target and trusting my eyes to give me a trend. The pictures appears
to "swirl" around the center. Hopefully enough leaves in the background
oriented in opposing directions would average out the structure.
So the question stands: is the background clutter structured and providing the
dominant affect, or is it the over/under corrected abberations of the lens.
One easy test for me to do is "paint" a grid of spaced dots across a flat
panel monitor, set focus for infinity, at F1.5, and see what happens. If the
effect is "reciprocal" I should get interesting results.
Closest Focus at F1.5, should be "worst case" for out-of-focus
http://mywebpages.comcast.net/brianvsweeney/summarit_close1a.JPG
http://mywebpages.comcast.net/brianvsweeney/summarit_close1b.JPG
Now a more moderate distance at F1.5
http://mywebpages.comcast.net/brianvsweeney/summarit_close3a.JPG
http://mywebpages.comcast.net/brianvsweeney/summarit_close3b.JPG
> Brian Sweeney wrote:
> >
> > Joe,
> > I am definitely not ruling it out! My "bet" on astigmatism is a Guess! I
> > am just pulling more people into it that can give me an explanation. If
> > it was
> > just my Summarit, I would expect problems with the in-focus image. It is
> > very
> > sharp. What I did for the oicture was the "pathological" case. Open up
> > to
> > F1.5, outdoors, on a sunny day, with lots of background clutter. Look at
> > the
> > Nikkor shot at F1.4. It was described as "bad Bokeh".
> >
> > DIDN'T ANYBODY think that my "Daddy has a Bad Bokeh lens" shot was
> > funny? The
> > out-of-focus highlights struck me as little "thought Bubbles" coming
> > from
> > Nikki's head. Hey, even if its BAD its got to be good for something?
>
> So... I wonder; why are you assuming that the light sources
> which are creating the ellipses in these pictures are points
> or circles. What if they're small lines, or extended sources
> which are elliptical or irregular rather than circular?
>
> This would not require the lens to have any particular defects,
> and so would comport with Ockham's razor (don't multiply entities
> without necessity)...
>
> You might answer "because the semimajor axes of a lot of the
> ellipses are perpendicular to radii extending from the center
> of the lens - and this is "sorta" true, but then look at the
> bright elliptical highlights on the radius extending directly
> up (i.e. 0 degrees) from center - the semimajor axes of these
> seem to be oriented at about 30 degrees, instead of parallel
> to the X axis as you'd expect...
>
> There are also "good" (i.e. nearly circular) OOF highlights
> just below center, and also along a radius at about 300 degrees.
>
> My guess is that these lenticular highlights are due in
> part to aberrations (my Summitar shows similar bokeh), but that
> this is not all of the story.
>
> --bob
From: Stefano Rumi [stefrumi@tin.it]
Sent: Mon 9/15/2003
To: Lenses@topica.com
Subject: RE: [LENSES] Please say "when" if you have enough...
Joe Polizzi wrote:
>
> Why would Sperical abboration be ruled out? I mean - I'm very new to
> lens design and theory, but it seems to me that if you have something
> that's designed to project a cone that makes a circle on what's supposed
>
> to be a flat 'plane of focus', but it's 'surprised' by the plane of
> focus being a sphere instead, then it would project an ellipse, right?.
Actually, lenses are designed to make cones which have their vertices on
the plane of focus. This happens, in the ideal lens, for object points
belonging to one plane (the one the lens is focused for); all other
cones have vertices in front or behind the plane of focus, which they
intersect making our beloved CoC's. If the lens has field curvature, it
means the those vertices belong to a curved surface instead of a plane;
this in undesired because the cones themselves will not cross the film
plane in correspondence of their vertices, forming a CoC. It's like
having a different focal length for different angles of view (this is
quite incorrect, but just to give the idea). This aberration is the
FIELD CURVATURE (or Petzval aberration). The optical system is capable
of creating real cones (that is, with point vertices), but these
vertices fall in the wrong place. Field curvature is nil in the center
of the image. Wider angles of view make it worse (or more difficult to
correct).
Spherical aberration affected lenses do not create light cones with a
proper vertex; the rays envelop (hope this is a correct english term...)
a caustic (...again...) and they don't all meet in the same point. This
can be described like having the central part of the lens with a
different focal length then the outer parts. Spherical aberration can be
found also in the center of the image. Wider apertures make it worse (or
more difficult to correct).
I think (I can be wrong, of course) we can rule those two aberrations
out as being responsable for the swirly effect of Brian's lenses,
because they theorically mantain the shape of the light cones; these
intersect the film plane and so they should yeld circles.
> But even besides that, the effect sort of reminds me of the coma I've
> gotten in astrophotography. It seems to me that coma only happens with
> 'small bright things against a dark background' - Is this the case?
That's why I think coma could be among the causes. It does change the
shape of the light cones. Like in previous posts, what I cannot
understand is how the cone-ish thing coming out of the lens has a round
base, a strange comet-shaped "point" say ten microns or so wide, is made
up of straight lines, and in between the circle and the quasi-vertex is
oval shaped with such big eccentricity!
I'm sure I'm missing something.
More tomorrow about small highlights...
> ..Or I suppose astigmatism wouldn't logically be ruled-out, because - as
>
> simple as my understanding of it is - if a thing is MORE out-of-focus
> perpendicular to the center, it would tend to be 'longer' in that
> direction; hence elliptical/radial-looking like that.
That's exactly like for the coma: I feel also astigmatism is involved
(maybe I would not bet real money on it like Brian would...), but again
I cannot figure out how such a tiny effect on the focus plane can give
such flattened circles.
Brian, have you got other nice figures that might help us?
> Oh, man! This is good stuff. ..Uh - I mean our discussion.
>
> Another question is: Is this distortion of OOF circles a known, common
> effect, or are we talking about some anomoly from this one Summarit of
> Brain's? One reason I'd like to know, is that if ALL Summarit 50/1.5s
> have this look, I think I want one!
I never noticed it before seeing Brian's post, certainly not with my
lenses (old Nikon AI's, VERY old Voigtlander for a much beloved
Ultramatic and new Voigtlander for my Bessa-R).
> You all may have heard me express my disgust for 'Holga photography' (I
> express it every time I get a chance), but I must admit that I HAVE seen
>
> Holga shots that were - uh ..well, OK - kind of beautiful (which
> disgusted me MORE, because when you're walking around with a HOLGA, you
> don't DESERVE to be making beautiful pictures). Brian's Summarit
> samples remind me of that kind of look that caught my eye. Don't you
> think, Brian? - it's the "better than a Holga" look.
>
> Joe
From rangefinder mailing list:
Date: Wed, 10 Sep 2003
From: Jubinville Michel juby@biancamedica.com
Subject: RE: Re[2]: Bokeh again
Hey Stefano,
Did you know that your full name is an anagram of "sfumato" ?(with
"enri" left over).
Sfumato if an oil painter term for pleasant out of focus background.
Michel
[From Wikipedia, the free encyclopedia. http://www.wikipedia.org/wiki/Sfumato:
Sfumato is a term coined by Leonardo da Vinci to refer to a painting technique which overlays
translucent layers of colors to create perceptions of depth, volume and form. In Italian sfumato means
"blended" with connotations of "smoky". ]
From rangefinder mailing list:
Date: Tue, 09 Sep 2003
From: brianvsweeney@comcast.net
Subject: RE: [RF List] Enough Bokeh
If it is relevant to RF cameras versus SLR cameras I hope that we can keep it
on-topic here, as well on the Lenses list.
Many users of RF cameras, at least of those on this list, seem to use wide-
angle lenses over telephoto lenses on your RF gear. Wide-angles on SLR's are
typically retro-focus (inverse-telephoto) design. As pointed out, this formula
usually produces inverse gaussian intensity profiles on the background blur
circles. The wide-angle lenses on RF cameras do not need to be retro-focus
designs, and should yield (subjective and a source of disagreement) "more
pleasing" results/ (objective) low-frequency results.
I will be shooting some comparison shots with my Nikkor RF 3.5cm F2.5 vs the
Nikkor SLR 3.5cm F2.8. I will also pitch the SLR 2.1cm F4 (same formula as the
RF lens) against the Nikkor-UD 20mm F3.5 that replaced it. All of these lenses
will be happy to get out for a while as opposed to seeing the short-telephotos
and fast normals having all of the fun.
The 5.8cm and 5cm SLR lenses produced "Platelet" like blur circles, inverse
Gaussian profiles, or "Bad Bokeh" (to some). Those are the normal lens
offerings for the Nikon F that are responsible for driving the RF line out of
production.
I find the relationship between the lens formulas and the "Background Blur
Circle Intensity Profiles" (BBC/IP) interesting. There may be a subjective
advantage for wide-angle lenses for RF cameras vs SLR's due to the required
back-focus to accommodate the mirror.
What people define as "Bad" and "good" is relative. If you open up your lens to
intentionally limit depth-of-field, you obviously care about the background
image interfering with your main subject. Whether you like the results with one
lens vs another is subjective. I like the results with my Summarit. It would be
hell to digitally reproduce that effect on a computer. Gaussian convolution is
easy. No one likes a lens labeled "Bad" when they personally like it. Unless,
perhaps it leads to give-away prices on EBay.
Sincerely,
Brian Sweeney
From: "Bandicoot" "insert_handle_here"@techemail.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Pentax Lens Bokeh
Date: Tue, 25 Nov 2003
"Bill Tuthill" ca_creekin@yahoo.com wrote
> brian brianc1959@aol.com wrote:
> >> http://pentaxuser.co.uk/egallery/albums/October_2003_gallery/MaryAllen.jpg
> >
> > It *appears* to me that the sample image shows bright-ring bokeh in
> > the foreground, and that the background bokeh is disturbed by
> > atmospheric turbulence. Not entirely clear that the lens doesn't have
> > good background bokeh. Of course, its optically impossible for a lens
> > to have ultra-smooth bokeh on both sides of focus (background and
> > foreground defocused points). You can have neutral bokeh on either
> > side, but most people don't consider neutral bokeh to be good bokeh.
>
> So do lens designers generally chose to have smoother bokeh on the
> far side than on the near side?
Yes. The reasoning being that you will far more often take a picture of
something in front of an out of focus background, than you will of something
partially obscured by an OoF foreground. Probably a reasonable assumption.
Nikon's DFC lenses let you choose which side of the plane of sharpest focus
the 'best' bokeh will fall, I'm not aware of anyone else doing this. I'm
also not aware of any lenses specifically designed to give better foreground
than background bokeh - probably be a very limited market, though it is the
sort of thing I could imagine Schneider or Rodenstock doing in LF lenses if
they saw enough demand. (That said, Nikon makes LF lenses, but not, as far
as I know, any that use their DFC mechanism.)
Here's a question: will reversing a lens place the 'good' bokeh on the other
side of the plane of focus from where it would be otherwise?
Peter
From lenses mailing list:
From: Brian Sweeney [brianvsweeney@comcast.net]
Sent: Thu 9/11/2003
To: rflist@topica.com Cc: Lenses@topica.com
Subject: RE: [LENSES] [RF List] Not Bokeh, its just like surveillance satellite orbits.
1: You are right, this discussion should be on the Lenses list.
2: I have been posting shots taken with my RF cameras and Lenses (ie having
fun using them) so I put them here.
3: I have been exploiting the Bokeh discussion (flame-war) as an excuse to
shoot at maximum aperture to find out what those lenses would do.
http://mywebpages.comcast.net/brianvsweeney/c7nikkorb.JPG
Nikkor 5cm F1.4 at F5.6
http://mywebpages.comcast.net/brianvsweeney/c7nikkor5_2a.JPG
If "Bokeh" is an optical property of a lens, we should be able to
characterize it. If "bad Bokeh" is just an opinion of a cluttered background
in a picture, it will always lead to a debate.
If the optical properties of a particular lens cause it to handle the out-of-
focus regions of a scene in a form that is distracting "or unnatural" that is
something that a ray-tracing program would indicate.
Optical Properties that "may" lead to a distracting background:
1: the intensity profile across the circle of confusion: Gaussian, tends to
blend points sources into each other with low-frequency. Inverse Gaussian
(platelet), tends to blend point sources into each other and
create "bright" "higher frequency" artifacts as the out-of-focus point sources
add together across the image.
2: The "trajectory" that the circle of confusion makes as it falls onto the
film plane. If all of the circles fell flat onto the film plane, an array of
out-of-focus point sources across the image would all look like circles. If
the trajectory is at an angle, they will look like ellipses.
3. Change in trajectory, angle of entry, as a function of distance from the
center of the image, the "eccentricity" of the ellipses change. I think that
is what produces the "swirly" effect of the Summarit. If I want a "dreamy"
(hallucinatory?) quality in my picture, I know what lens to use now.
If I understand the concept of Bokeh, and I may not, A perfect Bokeh lens
would 1: Have a Gaussian Distribution of the intensity profile of the out-of-
focus regions. 2: Have a perpendicular trajectory onto the film plane. 3: the
trajectory would always be perpendicular and not change with distance from the
center of the image.
This goes beyond what most lenses are designed for: producing a sharp and
undistorted image when focussed. Im am guessing that Telephoto lenses are as
close to my "perfect Bokeh" as a natural fall-out of their design.
Brian Sweeney
Initials BS
Coincidence? Not according to my Dad.
> Let's start calling the character of out-of-focus background areas
> "sfumato"... I mean, surely I can't be the only one who is tired of
> bokeh, bokeh, bokeh...
>
> Seriously though, folks, the Lenses list on Topica.com is the place for
> discussing lens characteristics, especially when they can't easily be
> quantified.
>
> Roger
>
> Work: www.adex-japan.com
from manual minolta mailing list:
Date: Sat, 6 Sep 2003
From: "Dave" SaalsD@cni-usa.com
Subject: Re: Minolta lenses with the best bokeh
Hi Mikail and wecome to the group. I shoot both Minolta manual focus
cameras and Leica M and R system cameras as well. I can assure you that
Minolta lenses are some of the finest ever produced. There are many fine
Minolta lenses that display that "artistic" quality that some refer to as
bokeh. A word derived from a Japanese word meaning the out of focus
rendition or look displayed by a lens. Some of the best in this regard are
the MC 58mm f/1.2 and MC 58mm f/1.4 lenses. These two "normal" focal length
lenses are legendary for their very smooth, fluid look to their images
produced. Another lens I am particular fond of is the MD 70-210 f/4 macro
zoom. This lens produces very sharp images with very nice bokeh. In fact
there are very few Minolta lenses that don't produce good artistic looking
images. If you would like to tell us what type of shooting you like to do
and what focal length lenses you require, I'm sure someone on this list can
recommend lenses that will fill your needs list. You have already
mentioned 50-135mm so the first three lenses I described would fill those
needs. The first version MD 135mm f/ 2.8 lens is also one that I like very
much. It is very sharp but has very smooth bokeh. I also like the MC 85mm
f/1.7 and the MD 100mm f/2.5 lenses for portrait use. I find the MC 85mm
f/1.7 a bit sharper than the MD 100mm f/2.5 but the 100mm lens has a bit
more reach and some find it better for tight headshot portraits. The MD
70-210 f/4 zoom is also a very good portrait lens and I have gotten very
good results with it as well. As someone once said, their are no "dogs"
among the Minolta manual focus lenses. Just some are a bit better than
others.
Hope this helps,
Dave Saalsaa
From manual minolta mailing list:
Date: Sat, 6 Sep 2003
From: "Dave" SaalsD@cni-usa.com
Subject: Re: New files added !
I have never seen an MC 50mm f/1.4 with a milled focus ring. They were
introduced after the switch to rubber grip versions. The MC 58mm f/1.4
might trip your trigger as it is a very nice relatively sharp lens with
superb bokeh. Or of course a first verson MC 58mm f/1.2 if you want the big
daddy of normal lenses. I have the later version MC 58mm f/1.2 with rubber
focus ring and like most of the later version lenses with rubber grip, they
have slightly better glass coatings to ward off flare better. But if you
are careful not to shoot directly into a light source and use the proper
lens hood, you will get great performance and a super smooth bokeh out of
the very underrated MC 58mm f/1.4. They are super cheap on ebay and the
perfect compliment to a classic SRT.
Dave Saalsaa
...
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Kiev Carl Zeiss/Arsat vs hassy C lenses? (I'm serious!)
Date: Thu, 09 Oct 2003
oranewbie wrote:
> People always remark about lens test between bronica and hasselblad that have
> been published in photo mags in Europe, Asia, or Antarctica but I haven't ever
> seen any posted on a website anywhere.
>
> Only one close that I've seen is from Bob's site. The blind test is
> an excellent idea which would help newbs like me get some help on the
> difference between zeiss and zenza, arsat, or whatever and cut through
> all the hype.
> It would be interesting to see if there was a consistent noticeably
> difference between the different manufacturers and if so how much.
The main "noticable" difference I see in different lenses is the bokeh/out
of focus areas of a print. On the kiev report we just finished a "double
blind" web test to see if people could tell the difference between a
Hartblei/Arsat 150mm f2.8 and a CZJ/Sonar 180mm f2.8. I was very close when
looking at the sharpness etc (actually the Hartblei was slightly sharper
and had a nice warm tone..) but to me it was fairly easy to pick the sonar
shots from the bokeh which is wonderfully smooth. For lenses I use at
smaller f stops for landscapes etc where almost all of the scene is in
focus, I can't see the diff between brands. It's the wider open shots with
shallow DOF that the good lenses show their stuff.
--
Stacey
From: rmonagha@engr.smu.edu (Bob Monaghan)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: blind 35mm lens tests
Followup-To: rec.photo.equipment.35mm
Date: 6 Dec 2003
Thanks for some good points and ideas for tests ;-)
We may need a suite of tests, perhaps a repeatable test for direct
comparisons (fixed night array, as you may be suggesting?) and a
subjective typical subject series as Lewis wants?
I can't recall anyone linking bokeh at macro distances with bokeh
performance at infinity, I would think lots of lens design issues might
intervene (i.e., maybe a lens where the entire lens moved (zeiss planar?)
would work, but a lens where element distances are varied, such as wide
angles with closeup corrections (nikon 24mm CRC..) might be problematic?).
I am interested in testing some lenses to see how the bokeh varies with
sample variation; I think I have 2 or 3 50mm f/1.4 nikkors I can use and
ditto 105mm f/2.5 etc.
I am in agreement about the 50mm f/2 nikkor; it is also perhaps the best
for macro work, and may well be the sharpest as well as cheapest of the
normal lens series to boot ;-) Again, this would be part of my interest.
I am wondering if Brian Coldwell's optical design software has enough
library lens designs, and the ability to project bokeh effects, to perhaps
provide an alternative approach too? Then the issue might be finding a
real world lens that performs as the designer intended? ;-)
but in the end, we are going to have to test these lenses for bokeh
effects if that is what we value, and that is part of the reason to think
this holiday season about how to setup such a test. I also think there is
merit in moving away from concern about lens resolution alone to other
factors like bokeh that can also impact image formation notably ;-)
regards bobm
Date: Sat, 06 Dec 2003
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: blind 35mm lens tests
Bob Monaghan wrote:
> yes, good point. Guess this means I should use the clear white lights (as
> I intended) and not the colored red/blue Christmas ones ;-) ;-)
That just reminded me of a photo showing a Christmas tree, and some light
effects:
http://www.nikon.co.jp/main/eng/society/nikkor/n02_e.htm there is also a
close focus shot of a flower. While some lenses focus closer than others, you
might be able to do an extension tube, or bellow test, and have an easier
defocus area rendition comparison.
> my worry on light brightness is more about the more distant background
> lights being bright enough to show well with a daylight background, though
> I like the size and repeatability. I'm going to do some test runs of the
> test first, but I have to get some lights and stands and so on ;-)
I think that a night exposure might work better. Using either mirror lock-up,
or mirror pre-fire (using self timer, etc.), would allow the camera to
settle, and have less chance of movement induced problems.
> any ideas on how far back such lights might need to be? optimal size of
> out of focus lights on slides? I suspect they would be fine, if large, for
> infront of subject bokeh tests (square law losses avoided..)? Now if I
> could just get one of my Xmas tree light happy neighbors to just setup
> their lights in the right way... ;-)
I understand your wanting to use * focus for common distance, but I think
standardizing a set closer distance would be much more useful. Does anyone
really look for defocus highlights from normal lenses at the * distance . . .
. . I doubt that happens often, and I think 2 m to 3 m would be more common.
> regards bobm
By the way, I have a Nikon 50 mm F2.0 AI as mentioned in that link above. It
is the deep barrel design, and not the short version. Compared to my later
f1.4 AIS, the defocus rendition is much
smoother, and with point light source, nor high contrast problems. I have
tried the Series E f1.8 (few samples), and a few of the f1.4, and f1.2 50 mm
Nikkors, and so far this f2.0 has the best defocus rendition. It also has
quick focus falloff, giving a distinct separation of the subject from the
background. It might be that this example I have was really well made, or it
could be that this particular lens is really that good.
Just something to think about with your upcoming 50 mm test, though I am not
sure if you have access to a 50 mm f2.0 AI. It compares very favourably to my
Leica 50 mm f2.0, though I am a little hesitant to state that all similar
lenses would perform the same, since I have only used one Leica 50 mm f2.0
(not enough sample variation).
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Mamiya 6 vs Hasselblad
Date: Sat, 20 Sep 2003
> "Stacey" fotocord@yahoo.com wrote ...
>> faneuil wrote:
>>
>> > Been shooting with a Mamiya 6 for a few months and so far quite happy with
>> > it.
>> > Of course, I still still the Hassies go up for sale (there are so many out
>> > there now) and still drool.
>> > Call it Hassie-lust, or whatever - but is it all nonsense? Is there
>> > something magical to Contax T* lenses?
>>
>> Depnds on the subject matter. For landscapes, you'll probably see no
>> difference whatsoever. For portrait type work (or anything shot at larger
>> f-stops with selective focus) you might be a difference in the out of focus
>> areas that would be more pleasing with the zeiss optics. That's been my
>> experience between using zeiss and soviet optics on my kiev/pentacons.
>> The soviet lenses are just as sharp but the "bokeh" isn't as pretty. This
>> is probably what people rave about with the leica optics and for some
>> people make the cost worth it. Other people can't see it as it IS a
>> pretty subjective thing.
>> Stacey
> Are you comparing Mamiya optics to Soviet optics?
As far as bokeh? Yep they seem pretty close..
Both are harsher than a zeiss lenses would be. Have you used both? I have
and the bokeh looks about the same in print.. Actually the sharpness at
working f stops (f5.6-f16) looks about the same as well. But then again no
one who has paid mamiya prices would admit a soviet lens could even be
close! :-) Most people who bash soviet optics have never used them...
The point was almost ALL modern lenses work fine for landscapes at f8-f16,
where most people will use them, and anyone would be hard pressed to see
any difference in print. Where you WILL see a difference in using zeiss
optics is at larger f stops in the out of focus areas of the image.. If he
never stops down less than f8-f16 and isn't doing selective focus type
shots, he'll never see any difference.
--
Stacey
From: azak@columbus.rr.com (Allen Zak)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Mamiya 6 vs Hasselblad
Date: 20 Sep 2003
Stacey fotocord@yahoo.com wrote
> Michael Scarpitti wrote:
> > There's nothing like a 'blad. I've used 'em and sold 'em to customers,
> > and I love 'em. I attended the 'blad sales school, and the notion that
> > an RB67 will give you better images was thoroughly demolished right
> > then and there. I wish everybody could attend that school.
>
>
> LOL like their "Sales school" is going to show you how a 6X7 negative
> produces =better= images? I wonder what Mamiya's RB67 "Sales school" would
> teach you about a 'blads 6X6 image size? You REALLY need to learn a thing
> or two about believing everything a manufacturer says about their own
> products!
I will have to agree with Michael about this. My opinion is based on
two show I saw several years ago. One was "I Dream a World," by Brian
Lanker, large B&W portraits made from 8X10 and Hasselblad negs. The
LF prints were, of course, superior, but the remarkable thing was how
well the 'blad pix held their own. You had to get real close to see
differences, often a matter of how well defined the stitching was on a
clothing seam, and I mean a small difference, at that. There was an
integrated look to the display, and I doubt anyone not looking for
them would have seen sufficient differences to be noteworthy. Very
impressive.
The other was a retrospective exhibit by Annie Leibowitz with a mix
of B&W and color prints from 35 mm, Hasselblad and Mamiya 67. The
'blad prints were clearly superior, despite the smaller negative size.
I think somewhere there was a report by Leibowitz that she preferred
the Mamiya because it wasn't as Harsh on her portrait subjects, or
something like that. But I like sharp and contrasty for everything,
and Zeiss delivers. I don't mean to imply the Mamiya stuff was bad,
but the blad was noticeably better, at least in those regards.
Those exhibits, not manufacturers' promotionals, made a believer out
of me.
Date: Tue, 23 Sep 2003
From: Zhang XK zhang_xiaokang@163.com
Subject: [Russiancamera] Re: Bokeh related question
To: Russiancamera-user russiancamera-user@mail.beststuff.com
Hi Rob.K,
The method the author used to check the blurred highlight is just a piece of
ground glass. Set the camera at bulb and put a chrome plated subject in
front of the tested lens at about 100x of the lens' focul distance. So for a
50mm lens,the subject will be placed at about 5 meters. Then focusing the
lens, you will see the high light on the subject changes from a sharp point
to a blurred image. Then he compared the images when the lens was set at 2
meters and 8 meters. He also mentioned that for some SLRs that has a plain
ground glass screen, one could just view the images from the view finder.
Another trick worth mentioning is a method to check the centering of a lens.
That is to shoot an image with the camera mounted at one side of a tripod
and shoot the same spot with the camera turned 180 degrees to the other side
of the tripod and compare the images with an enlarging glass. If there is
big difference in image quality, then the lens is not well centered. These
methods may not be useful for brand name optics, but for Russian optics? You
might be able to pick a best lens from a dozen to equal the lens of best
brand and still at a fraction of the cost.;-)
Regards
From: rmonagha@engr.smu.edu (Bob Monaghan)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: How many lenses in your kit?
Date: 12 Jan 2004
Hi David
quoting you:
Your point is interesting. I have seen it said (though I can't recall
where) that allowing the MTF to decline gracefully is good for bokeh,
whereas keeping it high to the greatest achievable frequency and then
having it fall like a stone (which seems to be the inevitable result of
"clinging on") is bad for bokeh. endquote
if so, then this is very bad news for digital users, isn't it? To match
lenses to digital sensor requirements, a rapid falloff above the nyquist
limit is very desirable for digital lenses (see schneider optical corp
website white paper on digital lens designs etc.). If you are right, then
such future digital lenses will have bad bokeh by design, yes?
great reason for keeping film alive, if you value nice bokeh ;-)
regards bobm
From: David Littlewood david@nospam.demon.co.uk
Newsgroups: rec.photo.equipment.35mm
Subject: Re: How many lenses in your kit?
Date: Sun, 11 Jan 2004
T. P. tp@nospam.net writes
>contaxman@aol.comnospam (Lewis Lang) wrote:
>>
>>Too sharp for portraits? Couldn't the same thing be said of any macro lens
>>regardless of bokeh?
>
>
>No, Lewis, not *regardless* of bokeh, because ultimate resolution and
>the smoothest bokeh are to a great extent mutually exclusive.
>
>Sharpness vs. bokeh is inevitably a compromise. Lenses that are
>optimised for ultimate sharpness (maximum MTF) tend to have harsh,
>unpleasant bokeh. Even the superb Leica M ASPH lenses have had to
>trade some smoothness of bokeh for their legendary sharpness - Leica
>users looking for the best bokeh should buy the last pre-ASPH versions
>of these lenses.
>
>The trick is to use *contrast* as the means to obtain apparent
>sharpness, rather than pursuing ultimate *resolution* - MTF being the
>product of resolution *and* contrast.
MTF is the percentage of subject modulation (approximately = contrast)
transferred to the image at different spatial frequencies of subject
detail (approximately = resolution). However, the equivalence of the
terms is far from exact.
I know you know what you are talking about, but others may be confused
by talking of MTF as if it is a scalar value, when it is in fact a curve
or function (hence the name).
> It is no coincidence that the
>lens manufacturers who have achieved good sharpness *and* good bokeh
>in the same lens all have available excellent lens coatings to reduce
>flare, thereby increasing contrast and therefore improving apparent
>sharpness (~MTF). They include Zeiss, Leica, Pentax ... and of course
>Tamron (Nikon and Canon have some lenses that achieve this, and others
>that don't, and I don't know very much about Minolta).
>
>The Tamron 90mm macro has very slightly less resolving power than most
>"pure macro" lenses, which are optimised for MTF. It is that (very)
>slight reduction in resolution that permitted the designer to offer
>outstanding bokeh. The excellent contrast achieved by Tamron's BBAR
>multi-coating allows the 90mm macro to appear sharp even though its
>resolution is slightly inferior to that of most modern pure macro
>designs.
>
>I have just purchased a lens adapter that will enable me to use my
>Pentax K mount lenses (and also any M42 lenses fitted with a Pentax K
>adapter) on my Leica bodies. That should make for some very
>interesting comparisons between Leica and Pentax glass, as all the
>focal lengths of my Leica lenses (24mm, 35mm, 90mm) are duplicated in
>my Pentax SLR outfit ...
>
Your point is interesting. I have seen it said (though I can't recall
where) that allowing the MTF to decline gracefully is good for bokeh,
whereas keeping it high to the greatest achievable frequency and then
having it fall like a stone (which seems to be the inevitable result of
"clinging on") is bad for bokeh. This appears to be related to what you
say (and may even be the same point). I wonder if there is any relation
to the effects of sharper/gentler band pass or rejection filters on the
quality of sound; the maths is certainly not totally dissimilar.
However, it is too difficult for my limited maths skills; must ask my
wife (a mathematician).
I guess this subject would be easier to analyse if someone had an
objective means of measuring bokeh...
--
David Littlewood
From: Alan Browne alan.browne@FreeLunchVideotron.ca
Newsgroups: rec.photo.equipment.35mm
Subject: Re: How many lenses in your kit?
Date: Sun, 11 Jan 2004
David Littlewood wrote:
> Your point is interesting. I have seen it said (though I can't recall
> where) that allowing the MTF to decline gracefully is good for bokeh,
> whereas keeping it high to the greatest achievable frequency and then
> having it fall like a stone (which seems to be the inevitable result of
> "clinging on") is bad for bokeh. This appears to be related to what you
> say (and may even be the same point). I wonder if there is any relation
> to the effects of sharper/gentler band pass or rejection filters on the
> quality of sound; the maths is certainly not totally dissimilar.
> However, it is too difficult for my limited maths skills; must ask my
> wife (a mathematician).
>
> I guess this subject would be easier to analyse if someone had an
> objective means of measuring bokeh...
The way I've seen "good bokeh" described wrt MTF is that if the
tangential and sagital MTF curves (as a function of radius from the
center of the lens) are parallel and close to each other, then the
"bokeh" will be smooth. If the sagital and tangential MTF's are
separated and/or nor parallel, then the bokeh will be harsh. In this
way a lens could be very sharp or not so sharp, but bokeh will be
reflected in the behavior of those two MTF curves.
Cheers,
Alan.
From: T. P. tp@nospam.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: How many lenses in your kit?
Date: Sun, 11 Jan 2004
contaxman@aol.comnospam (Lewis Lang) wrote:
>
>Too sharp for portraits? Couldn't the same thing be said of any macro lens
>regardless of bokeh?
No, Lewis, not *regardless* of bokeh, because ultimate resolution and
the smoothest bokeh are to a great extent mutually exclusive.
Sharpness vs. bokeh is inevitably a compromise. Lenses that are
optimised for ultimate sharpness (maximum MTF) tend to have harsh,
unpleasant bokeh. Even the superb Leica M ASPH lenses have had to
trade some smoothness of bokeh for their legendary sharpness - Leica
users looking for the best bokeh should buy the last pre-ASPH versions
of these lenses.
The trick is to use *contrast* as the means to obtain apparent
sharpness, rather than pursuing ultimate *resolution* - MTF being the
product of resolution *and* contrast. It is no coincidence that the
lens manufacturers who have achieved good sharpness *and* good bokeh
in the same lens all have available excellent lens coatings to reduce
flare, thereby increasing contrast and therefore improving apparent
sharpness (~MTF). They include Zeiss, Leica, Pentax ... and of course
Tamron (Nikon and Canon have some lenses that achieve this, and others
that don't, and I don't know very much about Minolta).
The Tamron 90mm macro has very slightly less resolving power than most
"pure macro" lenses, which are optimised for MTF. It is that (very)
slight reduction in resolution that permitted the designer to offer
outstanding bokeh. The excellent contrast achieved by Tamron's BBAR
multi-coating allows the 90mm macro to appear sharp even though its
resolution is slightly inferior to that of most modern pure macro
designs.
I have just purchased a lens adapter that will enable me to use my
Pentax K mount lenses (and also any M42 lenses fitted with a Pentax K
adapter) on my Leica bodies. That should make for some very
interesting comparisons between Leica and Pentax glass, as all the
focal lengths of my Leica lenses (24mm, 35mm, 90mm) are duplicated in
my Pentax SLR outfit ...
;-)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Lenses you crave
From: Magnus W vader@death-star.spam-trap.com
Date: Wed, 21 Jan 2004
Gordon Moat moat@attglobal.net wrote
> Rico Tudor wrote:
>
>> - Minolta 135/2.8 STF
>> Can't get enough spherical aberration? Tired of
>> pentagonal ghosting? Use this lens for bokeh done
>> right. Unique.
Sorry Gordon, my news server doesn't have the original post, so replying to
this...
The STF lens does /not/ "feature" excess spherical aberration to achieve
stunning bokeh. Instead it's the "apodization filter", a grey tinted
optical element, in the optical path that gives the unique bokeh and also
reduces the effective light transmission value to 4.5. Thus the somewhat
longish name: 135/2.8 [T4.5] STF. There should really be a "G", there, too,
but I guess only lenses fast for their class can be called that.
Date: Thu, 12 Feb 2004
From: Ian Gillis ip_gillis@yahoo.com
Subject: [Russiancamera] Re: "Bokeh"
To: Russiancamera-user russiancamera-user@beststuff.com
Here are the aforementioned web links, originally posted by Rob K.
The "leaf" link is the most interesting in terms of bokeh IMHO
Sip your green tea and let the bokeh carry you away...
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50-chart.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-park.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-cloth.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-bird.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-leaf.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-forest.htm
*****
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50-chart.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-park.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-cloth.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-bird.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-leaf.htm
http://www.asahi-net.or.jp/~hd9f-segs/lenstest50mm-forest.htm
******
Date: Sun, 15 Feb 2004
From: Leonard Flanagan ldflan@hotmail.com
Subject: Re: [Russiancamera] Re: "Bokeh"
To: Russiancamera-user russiancamera-user@beststuff.com
> I am not against a good bokeh but the way that only certain brand of
lens(not types of lenses like zooms vs primes) have a good bokeh. A $500+
normal lens won't have a much better bokeh than our J-8,J-3s.;-oc
Anyone who honestly evaluates lens performance and has any idea what they
are talking about would never say that "good bokeh" is limited to certain
brand names or nationalities. A 200mm Komura has bokeh identical to a Zeiss
Sonnar 180mm. The differences arise from lens design.
As to this notion of "subject" or "image" being more important than "bokeh",
to my way of thinking this is an utterly meaningless distinction drawn
simply to justify a curmudgeonly attitude.
Every image in which anything is left out of focus includes bokeh by
definition, just the same as an image includes colors if it was shot in
color. The background frames the "subject" if there is anything out of
focus in the picture. So bokeh is there, and it contributes to the image
quality and subject whether you think it's important or not.
Including in the evaluation of a photo a look at the out of focus areas is
no different from thinking about composition, lighting, perspective, focus,
contrast, etc., all of which may contribute to your asessment of it.
Sure a lot of people misuse the word, or use it as a substitute for
meaningful evaluation of images and lens characteristics; but there are
fools everywhere, aren't there? I really fail to understand why the simple
act of appraising the quality of bokeh is so controversial.
If you ask me, unlike "bokeh," adjectives like "painterly" and so on are
completely meaningless in this context without a lot more explanation of
what the hell is meant. Oil paintings run an incredible gamut from
"photo-realist" work to Rembrandt to impressionist with an incredible
variety of subjects, colors, compositions, brushwork, perspectives,
lighting, etc. Choices about emulsions, lighting, printing techniques,
composition, and so on all contribute far more than any lens to whether the
final photo seems like a painting...
At least with bokeh, the word has some actual meaning, and the effect is
actually a product of the lens and nothing else.
From: steven.sawyer@banet.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: Fri, 26 Mar 2004
The "creamiest" bokeh I've been able to obtain was with a "dimeniscus"
arrangement i.e. a meniscus lens with a diopter in front. I would consider this
to be a very "accidental" design. However, with a single meniscus arrangement,
even the focusing variant e.g. Goertz Frontar, I've been unable to duplicate
this effect. Although the "bokeh" I obtained with a dimeniscus arrangment was
super creamy, the background was not as "blitzed" out as what you'll find with
five or more element designs.
Jeremy wrote:
> Some lenses are known for
> their creamy Bokeh, and I find it hard to believe that this result was an
> accident.
Date: Wed, 24 Mar 2004
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Jeremy wrote:
> . . . . . .
>
> Puts does state in his article that he differs with most others in believing
> that Bokeh is not a conscious design decision. I've never used Leica
> lenses, so I can offer no qualified opinion on that point.
Well, I have, and I tend to like the wide open rendition of the older lenses
more than the newer ones. Maybe that means the newer ones are overcorrected,
though they are sharper, and capable of somewhat higher resolutions.
>
>
> I tend to disagree with Puts, on this point. Some lenses are known for
> their creamy Bokeh, and I find it hard to believe that this result was an
> accident. . . . . .
Perhaps with some strictly computer designed newer lenses it could be an
accident. Without hearing from the engineer responsible, it would be tough to
tell. That is one nice aspect of the Nikon articles I mentioned (there are more
than just for the 105 mm f2.5).
>
>
> . . . . . .
>
> I've never thought of my lenses as being appreciably less-sharp than others.
Probably not enough difference in results from hand held shots to see a
difference. With tripod shots . . . maybe . . . . .
>
> And Zeiss apparently still uses this formula in their Planar designs, and I
> don't recall ever hearing anyone question THEIR reputation for sharpness.
One thing that is amazing (to me at least) is seeing so many variations on
Zeiss designs. Obviously, start with a known good idea, and modify it, chances
may be better of getting a good result.
>
>
> From what I've read, the newer FA (Limited) series from Pentax uses an
> entirely different design. Apparently the lenses have improved sharpness
> rendition, while not compromising Bokeh. I don't know much else about the
> design. Perhaps someone more knowledgeable can fill us in.
>
> (Of course, the lenses I've discussed are not MF, but the Planar design is
> offered in both 35mm and MF).
You might find that some large format lenses were also Planar designs.
>
>
> Puts does seem to be accurate when he says that Bokeh MIGHT be measured
> scientifically but no one knows how and thus the subjective interpretations
> abound.
The best I have read on that so far, is that the nearness of the sagital and
tangential curves on an MTF chart could indicate nice defocus rendition. The
other thing I have heard is to look at the taper of the curve, and that a
slower taper could be better. Of course, an MTF chart is only a starting point;
using a lens under the conditions you intend to use it will give a better
indication. Some designs change quite a bit with distance of focus, while
others tend to not handle high contrast defocus areas well . . . basically many
variables. Probably many of us have tried supposedly great lenses, and found a
condition when the results were much worse than we expected.
>
>
> In spite of that, I know good bokeh when I see it, and I suspect most other
> photographers do, too.
Mostly, I have picked and chosen the lenses I currently use for work. I have
definitely had some unacceptable lenses in the past, though luckily those have
been rare exceptions. Going back to the original poster, it is interesting that
some of the simpler designs do so well with defocus areas.
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: "Jeremy" jeremy@nospam.thanks.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: Wed, 24 Mar 2004
> brian wrote:
>
> >While its true that many lens designers have no
> > clue what bokeh is, this is certainly not universally true. How else
> > could you explain lenses like the 105mm and 135mm DC Nikkors?
>
> > Also,
> > near the optical axis, the *only* aberrations possible in a
> > rotationally symmetrical optical system are spherical aberration and
> > axial chromatic aberration. Chromatic aberration just doesn't help at
> > all in achieving good bokeh. Lenses with excellent bokeh have
> > slightly undercorrected spherical aberration throughout most or all of
> > their image field.
>
Puts does state in his article that he differs with most others in believing
that Bokeh is not a conscious design decision. I've never used Leica
lenses, so I can offer no qualified opinion on that point.
I tend to disagree with Puts, on this point. Some lenses are known for
their creamy Bokeh, and I find it hard to believe that this result was an
accident. In the case of my own SMC Takumar (Pentax screw-mount) lenses,
editor Mike Johnston published an article explaining its exceptionally good
Bokeh. Apparently Pentax followed the design of Carl Zeiss. Here is what
Johnston saya about the SMC Takumar 50mm f/1.4 normal lens:
"All these lenses are classic Planar designs, as are more or less every fast
50mm except for the Leica M lens, which is an idiosyncratic design unique to
Leica; but where most makers have economized by making the surfaces between
the fourth and fifth elements flat, Pentax has always stuck with the
original design and used cemented spherical surfaces there. Aside from being
more expensive to manufacture, this results in a lens that is slightly less
sharp at infinity in the plane of focus, but that has better off-axis
aberration correction and thus, better bokeh or blur."
I've never thought of my lenses as being appreciably less-sharp than others.
And Zeiss apparently still uses this formula in their Planar designs, and I
don't recall ever hearing anyone question THEIR reputation for sharpness.
From what I've read, the newer FA (Limited) series from Pentax uses an
entirely different design. Apparently the lenses have improved sharpness
rendition, while not compromising Bokeh. I don't know much else about the
design. Perhaps someone more knowledgeable can fill us in.
(Of course, the lenses I've discussed are not MF, but the Planar design is
offered in both 35mm and MF).
Puts does seem to be accurate when he says that Bokeh MIGHT be measured
scientifically but no one knows how and thus the subjective interpretations
abound.
In spite of that, I know good bokeh when I see it, and I suspect most other
photographers do, too.
Date: Wed, 24 Mar 2004
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
brian wrote:
> "Jeremy" jeremy@nospam.thanks.com
> > Erwin Puts, the noted Leica specialist, has published the following
> > observations about Bokeh:
> >
> etc., etc., . . . .
>
> Jeremy, you can believe whatever you want, but if you choose to
> believe all of the stuff that Puts writes then you will only be
> mislead. Erwin Puts is no lens designer, as the passage you quote
> makes quite clear. While its true that many lens designers have no
> clue what bokeh is, this is certainly not universally true. How else
> could you explain lenses like the 105mm and 135mm DC Nikkors?
Just to add a little to this, it does seem that the 105 mm f2.5 was designed specifically with a consideration of
defocus rendition. There is a nice article about these considerations, and the engineering at:
http://www.nikon.co.jp/main/eng/society/nikkor/n05_e.htm
> Also,
> near the optical axis, the *only* aberrations possible in a
> rotationally symmetrical optical system are spherical aberration and
> axial chromatic aberration. Chromatic aberration just doesn't help at
> all in achieving good bokeh. Lenses with excellent bokeh have
> slightly undercorrected spherical aberration throughout most or all of
> their image field.
There is a mention in the above article that a switch from a Sonnar type design to a Xenotar type design improved
aberration correction. While this makes sense to me, is that what effected the reduction in Coma? Would that reduction
in Coma directly relate to improvements in defocus rendition? Thanks!
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: 24 Mar 2004
"Jeremy" jeremy@nospam.thanks.com wrote
> Erwin Puts, the noted Leica specialist, has published the following
> observations about Bokeh:
>
etc., etc., . . . .
Jeremy, you can believe whatever you want, but if you choose to
believe all of the stuff that Puts writes then you will only be
mislead. Erwin Puts is no lens designer, as the passage you quote
makes quite clear. While its true that many lens designers have no
clue what bokeh is, this is certainly not universally true. How else
could you explain lenses like the 105mm and 135mm DC Nikkors? Also,
near the optical axis, the *only* aberrations possible in a
rotationally symmetrical optical system are spherical aberration and
axial chromatic aberration. Chromatic aberration just doesn't help at
all in achieving good bokeh. Lenses with excellent bokeh have
slightly undercorrected spherical aberration throughout most or all of
their image field.
Brian
www.caldwellphotographic.com
From: "Jeremy" jeremy@nospam.thanks.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: Mon, 22 Mar 2004
"germano" germano.colla@libero.it wrote ...
> steven.sawyer@banet.net wrote
> > I've been experimenting with antique cameras for some time and I've come
> > to a somewhat controversial conclusion, which is based on experience
> > alone. I believe that the fewer elements you have the less "blitzed
> > out" your bokeh is, that is to say the less your main subject stands out
> > from the background. Has anyone else noticed this?
> > Thanks
>
> No.My folder camera (Bessa II with 105/3,5 color-heliar 5 elements
> with multilayer color)have a best wonderful bokeh in the
> world.Seriously.
Erwin Puts, the noted Leica specialist, has published the following
observations about Bokeh:
"Bokeh is not a function of spherical aberration and number of diaphragm
blades. Clearly the out-of-focus areas in front of and after the sharpness
plane are different depending on the overall aberration correction, which
involves much more than just the correction of spherical aberration.
Bokeh is not (and here I differ from almost anyone) a conscious design
decision. Lens designers focus all their creativity to the plane of best
focus and try to get an image quality that is consistent with their goals.
As a general statement I would say that the clear rendition of extremely
fine detail with high contrast and excellent
shape preservation over the whole image area and over all distances and
apertures would be the idea. This is not easy to accomplish and so
compromises have to be made. A certain 'residue' of aberrations will be
present in every lens. What this residue is composed of, depends on the
compromise made. Now it is easy to understand that the way the plane of
sharpness is defined has a bearing on the unsharpness areas in front of and
beyond this plane. So the unsharpness rendition is a direct function from
the degree of correction of the sharpness plane.
So bokeh might be detectable in older Leitz lenses, but this is not a design
decision, just the result of the overall correction.
Modern lenses indeed have less bokeh as I understand the idea, they are
corrected to a much higher degree than older Leica lenses."
Contrast that with what Carl Zeiss says in their brochures--something to the
effect that Zeiss lenses have the most beautiful bokeh of all lenses . . .
One company makes no attempt to optimize bokeh while another company designs
their lenses with bokeh in mind. Go figure . . .
Puts does make one statement that puts this all in perspective:
"Bokeh is a very elusive concept. It is related to the shape of out-of focus
object details and the light-energy distribution within the unsharpness
patches. It might be measured scientifically but no one knows how and thus
subjective interpretations abound."
Finally, Bob Monaghan's Super Site notes that, on blind tests, people have
been unable to tell which brand of lens produced which negative. I can't
help but wonder how much of these elusive lens characteristics are really
detectable, and how much of it is in our own minds.
One thing is apparent--the photographer is much more critical of these
factors than is the person that is viewing the image. He is almost always
more concerned with things like composition, exposure and subject matter,
rather than being critical on the out-of-focus areas.
Date: Thu, 18 Mar 2004
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
steven.sawyer@banet.net wrote:
> I've been experimenting with antique cameras for some time and I've come
> to a somewhat controversial conclusion, which is based on experience
> alone. I believe that the fewer elements you have the less "blitzed
> out" your bokeh is, that is to say the less your main subject stands out
> from the background. Has anyone else noticed this?
> Thanks
I have several folders, and I do notice an overall smoothness to the
backgrounds. However, I think it might be the lack of contrast, and overall
softness of rendition. Stopping down helps, or push processing the film to
bump the contrast up. Sometimes filters can help a bit as well.
Another guess is that there is more spherical aberration in a triplet lens
design. The flaws in ancient designs might actually help some aspects of
the images. Some of these designs work nicely for portraits.
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: Jeff Sumner jdos2@mindspring.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: Tue, 23 Mar 2004
> Bokeh isn't a big deal at all; until you shoot something really nice but for
> some reason the OOF background is so distracting it's pulls you eye to that
> instead of the in focus subject!
Actually, that's the best summation, methinks.
I had a Novar/Ikonta and though sharp stopped down to f/11, wide open
it's out-of-focus rendering was a target shape behind my isolated
subject. It was EXTREMELY distracting in several pictures, so I didn't
find the camera as useful as I'd have liked. I now have a Tessar on an
Ikonta (40$, Best Camera Buy This Year) which has a much more pleasing
rendition when shooting in the evening light- trees don't have a
horribly circular smudge look, at least nearly as much.
Then again, I don't overmuch like the out of focus rendition of the
Tessar, either, but stopped down past f/5.6, I don't notice it.
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: 20 Mar 2004
> So, my conclusion is that all Xenotar-type lens designs
> have this particular rendering...
I'm going to assume that Xenotar means double-Gauss. Its true that
many double-Gauss designs have poor wide-open bokeh due to the way low
order spherical aberration is balanced with high order spherical
aberration. But to make a general conclusion is clearly wrong. For
example, the original Vivitar Series 1 90mm macro lens is a
double-Gauss design with exceptionally good bokeh since it has just
the right amount of uniformly undercorrected spherical aberration.
Brian
www.caldwellphotographic.com
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: Fri, 19 Mar 2004
nicholas wrote:
> David J. Littleboy wrote:
>> But I suspect that the number of blades in the iris makes more of a
>> difference than lens design.
>>
>> David J. Littleboy
>> Tokyo, Japan
>>
>>
> I have to disagree on this point, not that I know the exact difference
> number of blades have to do with bo-keh...
> Having used Rolleis for awhile now, the OOF parts of a Xenotar-type lens
> print is worse than the Tessar-type (Xenar) lens--from my observations.
> Regardless of aperture (obviously the further stopped down the more in
> focus :-). But yeah, a Xenotar lens type has worse OOF rendering.
> Perhaps, worse than most six element lenses I would wager...
And I have two different 80mm 6 element lenses for my Kiev, one has nice
smooth bokeh and the other doesn't and both have the same number of blades
in the iris. I have a tessar clone 300mm LF lens that has nasty "clumpy"
bokeh and the diaphram has what looks like 50 blades! My 3 element 210mm
geronar has nice bokeh and 1/4 the number of blades and 1 less element. The
300mm heliar has nice bokeh again with like 50 blades so I know in this
case it's the lens design not the number of elements or number of blades.
I don't think the # of blades is a big deal unless it has a really low
number of them, like 5 or less. Even then it's more likely to just show up
as "diaphram flare" rather than effect the bokeh. My old olympus XA only
has 2 blades and it works pretty good! :-)
Almost any of the older folder lenses will have a bunch of blades so I doubt
that is the cause for the OP's -problem-. More likely it's that the "low
number of elements" lenses are on low end models and used crappy glass/poor
designs/low QC etc.
--
Stacey
From: "KM" nospam@net.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: Fri, 19 Mar 2004
"David J. Littleboy" davidjl@gol.com wrote
> But I suspect that the number of blades in the iris makes more of a
> difference than lens design.
But background blurring's most striking at the widest aperture, when the
number of aperture blades doesn't matter.
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: Thu, 18 Mar 2004
steven.sawyer@banet.net wrote:
> I've been experimenting with antique cameras for some time and I've come
> to a somewhat controversial conclusion, which is based on experience
> alone. I believe that the fewer elements you have the less "blitzed
> out" your bokeh is,
I think it's that many of the 3 element lenses are just have crappy QC and
aren't sharp till they are stopped down so they don't give a "3D look. Many
multi element lenses have horrible bokeh so that doesn't promise anything.
I have a couple of modern cooke triplets that have wonderful bokeh so I
don't think this "number of elements" has much to do with it.
--
Stacey
Date: Fri, 05 Mar 2004
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Pro Lenses : Nikon or Canon
Lewis Lang wrote:
> Hi Tony:
>
> SNIPS
>
> >The 50mm f/1.4 Nikkors are all over-corrected designs that perform
> >poorly at the edges wide open (and down to about f/5.6) and exhibit
> >some of the harshest out-of-focus effects that you will ever see in
> >any 50mm lens. Only the later 50mm f/1.8 Nikkors are worse.
>
> This is quite perplexing. Did I luckout with my 50/1.8 Series E lens. I have
> the 50/1.8 Series E (which most/all? later/current designs up to AF are
> supposed to be based on) and I find its bokeh to be superlative in both its its
> 3-D separation of subject planes (as I've noted many times before on this
> newsgroup) and its smoothness (though I'm pretty sure, based on my 50/1.7 A and
> 50/1.4 K? experience that the 50/1.4 A Pentax would outdo it in the smoothness
> of bokeh area).
I am going to throw a wrench into this discussion. It seems that almost all MTF
charts are based upon focus at infinity. Those of us who choose lenses for their
defocus area rendition likely do not use these lenses at infinity when we want to
maximize that smoothness quality in our images.
> Would you include the 50/1.8 Series E in your assesment, and if
> so what do you find so horrible about its bokeh? I thought that the Canon
> 50/1.8 Ef and Nikon 50/1.4 lenses were supposed to be the ones with noticably
> bad (nisan/double edged line imaged, at least for the Canon) bokeh. I find my
> 50/1.8 Series E to have complex bokeh that erases details in detailed
> backgrounds and therefor emake attention pop to the subject - its complex
> bokeh, but still beautiful bokeh, though not as smooth as the Pentax/Leica (and
> sometimes Minolta/Olympus) kind of "buttery smooth" bokeh.
I found that my older 50 mm f2.0 AI (long lens barrel design with recessed front
element) to give better defocus rendition than my 50 mm f1.4 AIS. However, when
the light levels are low, the f2.0 does not do as well as the f1.4 with any lights
in the defocus areas. Neither of these lenses will show those characteristics when
focused at infinity.
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 05 Mar 2004
Subject: Re: Pro Lenses : Nikon or Canon
Hi Tony:
SNIPS
>The 50mm f/1.4 Nikkors are all over-corrected designs that perform
>poorly at the edges wide open (and down to about f/5.6) and exhibit
>some of the harshest out-of-focus effects that you will ever see in
>any 50mm lens. Only the later 50mm f/1.8 Nikkors are worse.
This is quite perplexing. Did I luckout with my 50/1.8 Series E lens. I have
the 50/1.8 Series E (which most/all? later/current designs up to AF are
supposed to be based on) and I find its bokeh to be superlative in both its its
3-D separation of subject planes (as I've noted many times before on this
newsgroup) and its smoothness (though I'm pretty sure, based on my 50/1.7 A and
50/1.4 K? experience that the 50/1.4 A Pentax would outdo it in the smoothness
of bokeh area). Would you include the 50/1.8 Series E in your assesment, and if
so what do you find so horrible about its bokeh? I thought that the Canon
50/1.8 Ef and Nikon 50/1.4 lenses were supposed to be the ones with noticably
bad (nisan/double edged line imaged, at least for the Canon) bokeh. I find my
50/1.8 Series E to have complex bokeh that erases details in detailed
backgrounds and therefor emake attention pop to the subject - its complex
bokeh, but still beautiful bokeh, though not as smooth as the Pentax/Leica (and
sometimes Minolta/Olympus) kind of "buttery smooth" bokeh.
TIA
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Pentax Lens Bokeh
Date: 22 Nov 2003
T P tp@nospam.com wrote
> "Jeremy" jeremy@nospam.thanks.com wrote:
>
> >Can Leica beat this?
> >
> >http://www.pentaxuser.co.uk/egallery/albums/October_2003_gallery/MaryAllen.jpg
>
>
> Yes, Leica lenses can easily beat that. This shot is a poor choice
> for any such comparison, because it displays bokeh that is far from
> smooth, with some very obtrusive (and subjectively very unpleasant)
> bright ring highlights. If smooth bokeh is considered an important
> aspect of lens performance, the shot demonstrates a poorly designed
> optic. Anyone claiming this as an example of good bokeh clearly has
> not even the most elementary understanding of what good bokeh is.
>
> Unfortunately, several Pentax lenses display such poor design, sadly
> including the three recent (and extremely expensive) "Limited Edition"
> lenses. Pentax claim these were designed with bokeh as a priority,
> but they actually show the harsh bokeh that is typical of a design
> that has been over-optimised to gain a high MTF index at the expense
> of other important optical characteristics such as bokeh and
> distortion.
>
> Of course what we have here is just another example of Jeremy's
> profound ignorance of even the most basic principles of optics. His
> obsession with his sadly outdated, and by 21st century standards,
> optically inadequate screw mount Takumar lenses precludes any
> possibility of objective judgement, whether quantitative (as with MTF)
> or qualitative (as with bokeh). Jeremy's absolute ignorance (or is it
> stupidity?) means that he continually claims that his obsolescent
> Pentax lenses are the optical equivalent of today's Leica and Zeiss
> glass when they are patently not.
>
> Some more modern Pentax lenses equal Leica and Zeiss equivalents in
> one optical characteristic, for example bokeh, or apparent sharpness.
> But there are very few Pentax lenses that can compare with Leica and
> Zeiss for a combination of two or more such characteristics. With
> few, if any, exceptions, Pentax lenses are like most others; they are
> compromised in some way to obtain a target price point.
>
> Those select few Pentax lenses that do offer a combination of
> sharpness and bokeh that could be compared with Leica and Zeiss glass
> fall down in other areas, notably distortion, where many Pentax lenses
> show rectilinear distortion that would not be acceptable to other mass
> manufacturers such as Nikon and Canon, let alone Leica and Zeiss.
>
> Where Leica and Zeiss beat Pentax, and by a huge margin, is in the
> careful optimisation of an optical design so that exemplary standards
> of resolution, contrast, flare resistance, distortion, aberrations, 3D
> micro-contrast and out-of-focus effects can be obtained *all at the
> same time*. Pentax have not yet shown that they can achieve this,
> whether in the 1970s, the 1980s, the 1990s or now.
>
> Unfortunately, Jeremy's complete lack of knowledge of even the most
> basic of optical principles allows him to select a photo which serves
> to prove only that Pentax lenses are a very, very long way behind
> those from Leica and Zeiss. And given the disappointing performance
> of the "Limited" lenses, with harsh bokeh and truly alarming levels of
> distortion, especially for the very high prices charged, it looks
> unlikely that Pentax will ever catch up.
>
> Meanwhile, Jeremy floats on his cloud and plays with his screw mount
> Pentax lenses, completely oblivious to their inadequacy when compared
> with Zeiss and Leica glass. Oh what a sad man he is.
It *appears* to me that the sample image shows bright-ring bokeh in
the foreground, and that the background bokeh is disturbed by
atmospheric turbulence. Not entirely clear that the lens doesn't have
good background bokeh. Of course, its optically impossible for a lens
to have ultra-smooth bokeh on both sides of focus (background and
foreground defocused points). You can have neutral bokeh on either
side, but most people don't consider neutral bokeh to be good bokeh.
Brian
www.caldwellphotographic.com
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 26 Nov 2003
Subject: Re: Anyone use a single focal length?
>Subject: Re: Anyone use a single focal length?
>From: Roger leica35@yahoo.com
>Date: Wed, Nov 26, 2003
>contaxman@aol.comnospam (Lewis Lang) wrote:
>
>>but I find the 50mm opens up graphic
>>composition and selective focus effects (not to mention "bokeh") _for me_ that
>>seems to complement the portraiture/whatever else it is that I do.
>
>Lewis,
>
>What 50mm lens are you using that you find remarkable in the "bokeh"
>department?
>
>Regards,
>Roger
Hi Roger:
The answer....
Drum roll please....
Series E Nikon 50mm f/1.8.
It has complex bokeh that makes the subject pop out more than equivalent 50mm
lenses (Konica, Yashica, etc.) by blurring the background details more than
what would normally happen w/ other f/1.8 and f/2 lenses when used wide open.
Its bokeh is like a built-in soft focus filter on just the background alone,
diminishing distracting deatil into nice less-detailed and/or near-detailless
patterns of shape/color whilst the subject remains super sharp (and I do mean,
_super sharp_). It even gives this effect out to about 5 feet or so when you'd
think the depth of field would be too great even wide open and allow for
distracting background detail. The fact that this "average" "normal" lens is
cheap and very widely available is just an added bonus. Its one detriment is
that its probably only single coated (or at least not as multi-coated as other
Nikon lenses) so it does have some flare. But block out the flare w/ a hood or
a hand or a gobo and you'll have one of the most sharpest, color saturated, 3D
bokeh lenses on the planet. It does have some slight bright ringing (normally
considered ("bad bokeh" ) of the hilights but nothing that's really
distracting, to me, at least. The overall effect, when used for portraiture is
sheer wonderfulness. My only regret is that it doesn't fit on my Contax MF but
there may be an adapter somewhere to allow me to use it on my Maxxums (in MF
mode only of course). Its equal is the Pentax 50/1.7 A lens whose
distinguishing characteristics are buttery smooth bokeh to make Leica cry for,
a high degree of in focus subject clarity that can approach "3Dness" if not 3D
itself (though the subject and other planes don't seem to separate as much as
the Nikon Series E 50/1.8, subject clarity w/i the subject's plane of focus is
just perfect (for me)), and a high degree of color saturation yet a natural
look to the contrast and micro-contrast). Its not quite a Leica in
tonality/microcontrast but its so clear in its own way you don't give a damn
about the branding. Flare should be much better than the Nikon E lens though
i've never done a side by side. Other standout lenses are the 50/1.4 Zeiss
Contax MM lens and the 50/2 Summicron R (never tried the M version) as far as
high micro (and overall too) contrast and clarity, and bokeh was probably
pretty decent w/ these lense but I'd have to search my files for prints of
their bokeh signatures when used wide open (I tended to shoot most lenses
stopped down when I owned the Pentax/etc. lenses in the '80's) which were
probably good but not in the 3D way of the Nikon E lens and the Pentax A 50/1.7
is so clear and buttery smooth that I really don't care if other high end
lenses match it for clarity/bokeh, I just enjoyed it when I had it (in the
early-to-mid '80's). Lastly, before I forget, though it may not have 3D bokeh
in terms of background/foreground blur (though I know at least its background
blur is superb when I tested it out), if you consider _in-focus_ subject
clarity as part of an expanded definition of bokeh (which usually just covers
oof areas and other optical properties of the lens such as diaphragm shape, coc
light distribution, flare?, etc.) then the top lens of all time might be the
Pentax 31mm f/1.8 Ltd. lens which becomes a "50mmish" lens when used on the
Pentax *ist D DSLR w/ its 1.5x equivalent magnification factor. Simply superb
and an equal if not much better wide open to the Leica M 35mm f/2 Summicron (I
can't speak for the asph version of this lens and the 35mm 1.4 Summilux, but
I've heard that the asph lens sacrifice some smoothness of bokeh for lens
sharpness wide open). The 31mm Ltd is tack sharp wide open and looks like most
lenses in sharpeness when they're stopped down to f/8 - its that good, wide
open, plus as a bonus you get unmatched 3D clarity that beats all if not most
35mm format lenses that I have had experiences with on this planet. Though I
will/do admit that w/ a digital SLR you are cropping out the edges so I can't
speak for its edge performance but its center performance both in 3D clarity
and sharpness wide open at f/1.8 is to die for. Bokeh is buttery smooth too (w/
a slight hint of mocha and mint ;-))..
Anyway, that's my long winded take on the subject - somebody must have if not
pushed my bokeh button, then pulled my bokeh finger ;-).
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
Date: 30 Nov 2003
Hi Bob:
>Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
>From: rmonagha@engr.smu.edu (Bob Monaghan)
>Date: Sat, Nov 29, 2003
>
>
>Wow, thanks for the detailed comments and ideas ;-)
You're welcome :-). I hope it comes in handy! ;-)
The only big problem
>is that the dang trees around here are losing their leaves, so I have got
>to do some looking to see if there is still a convenient site for this
>Xmas to do a trial shoot? ;-)
Perhasp a park service, book or webiste on your areas might know of parks/etc.
w/ year round folliage/leaves on trees? Just a thought...
>when I said I disagreed in believing... I meant I disagree with those who
>believe we could just solicit samples of bokeh from multiple users of
>different subjects, and that I believed that we needed to keep the same
>subject and lighting conditions to reduce variables, just as you stated,
>and what I did with my medium format blind lens tests, so we agree again
>;-) I just worded that poorly, and the telnet bundled with this browser
>doesn't let me quote or even copy and paste, so retyping is hard on memory
No problem:
>I doubt you/we will get much in the way of informative comments on bokeh
>shape, though we can ask.
Never hurts to aks, and if you're going to do a test, might as well make it
detailed/worthwhile for future generations to argue about ;-).
I found that my two page blind test form (see
>html version at http://medfmt.8k.com/mf/blindtest.html
I'll have to check it out.
- solicited useful
>info on photogr. experience, loupe viewing setup/power etc.
>I was going to do a telephoto lens comparison with medium format lenses as
>a followup to the normal lens test, but there the necessity of dealing
>with close focusing and errors is major issue.
Telephotos in 35mm alone have to be focused pricely, MF I would suppose even
more so since at equivalent angles of view (to their 35mm equivalents) the MF
has even less depth of field :-(.
>I'm not wedded to 8-10 feet as a test distance, but select it as that is a
>common distance setting for normal lens users.
Bokeh of a 50mm lens set at 8-10 feets is near non-existant. Better to test it
at 4/12 feet away (or 5 at the most), if you want this to be a worthwhile test.
At 8 feet w/ a 50mm lens your normal lens user is more concerned w/ getting all
of their subject in frame and doesn't give a whit about (background) bokeh.
Stick w/ 4 1/2 to 5 feet and you'll do fine/have some bokeh effects worth
seeing/testing/rating. I can't strees this strongly enough or enough times :-).
Nor am I insistent on
>f/8-f/16 shots in a bokeh test,
;-)
but some may want to see these settings
>too.
I doubt it. On a 50mm lens set at f/8 or higher w/ the subject about 5 feet
away there wont be much out of focus in your background to be even described as
bokeh since there wont be much blurring of the background to judge bokeh -- but
if you want to make more needless work for yourself ;-), plus there's always
the bokeh at f/22 to think about/test too ;-) ;-).
Accurate focusing on the main subject at 4-5 feet may vary,
Practice (focusing), and not by enough to make much of a differnce on subject
sharpness or background bokeh if you are able to focus reasonably well.
despite
>efforts, but as I noted, we aren't evaluating resolution in the subject
>plane in this test, but background bokeh.
Definitely.
I will think about an extra
>fixed (not water spray ;-) foreground subject for foreground bokeh checks,
>but this may be problematic unless I find just the right site.
You can always bring a potted plant and set it on a folding table in the
foreground so it will be more or less at the same height as the subject, just
closer to the camera (for note/record, you also might want to measure camera to
foreground distance too, along w/ camera to subject and camera to middleground
objects at various distances behind the subject). I would strongly suggest
bringing some extra objects (even more (larger) potted plants to put 2 feeet,
5feet and 7 feet behind your subject so we can get an idea about image cohesion
and how rapidly focus falls off for each lens and whether there are any bokeh
problems in the out of focus middleground objects behind the subject.
The MF test
>ended up being a pretty big project, with 10 camera bodies and 13 lenses
>and meters and a heavy tripod, cable releases, paperwork, photocopied
>large random numbers for putting in each shot (so the slides can't be
>mixed up), tape to hold that down, film, lens hoods for all, camera
>batteries, and so on ;-) Dang, just like work ;-)
:-( ;-) But some things are worth it in the end... (knowledge and enjoyment),
beats vegging in fron of the tv to yet another rerun of an episode you've seen
twelve times already ;-).
>but I keep being amazed that we argue a lot about this stuff, when all it
>would take is a few simple tests and some slide sets to be able to
>document issues like camera shake effects, MLU, bokeh effects, and so on.
>
>grins bobm
Arguments are cheap, they're the cheapest form of "gas" around. Experience is
almost like work, almost everyone is willing to share it but almost nobody
wants to have to do it themselves unless they get paid for it. And so, to put
my mouth where my mouth is (or, perhaps, my foot where my mouth is), at least
let me say thank you in advance for this test/experience, even if I can't pay
you in real money.
{APPLAUSE} (and/or apple sauce, pick whichever is your favorite ;-).
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 29 Nov 2003
Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
Hi Bob:
>Subject: blind 35mm lens tests - was Re: Pentax Lens Bokeh
>From: rmonagha@engr.smu.edu (Bob Monaghan)
>Date: Sat, Nov 29, 2003
>
>re: flare test I can't recall exactly which book by Roger Hicks and
>Frances Schultz, I have a number of their books too ;-), but I suspect it
>was The Lens Book, which describes their go/no-go lens testing, using a
>single roll of film, to assess flare, resolution etc. The black branches
>or power lines against the bright sky is a rigorous test for veiling glare
>type flare; you can also shoot into the sun or better yet at night with
>bright light source to really see how lens handles flare, effects of
>stopping down, and so on ;-) I also like that this real world test gets
>around critics who carp that lens test chart testing is not real world ;-)
Yup :-). {IN MY BEST HANK HILL VOICE ;-)}
>re: disappointment with bokeh tests
>the highlights off the fountain show some interesting differences, with
>some lenses yielding more "colorful" patterns (at high loupe powers) from
>some kind of prismatic effect(?),
Water drops/jets refracting light at different angles makes for some nice
prismatic effects ;-).
>but I realized that I was missing out on
>the really important bokeh info. I tested the effects of foreground
>highlights, but few lenses are optimized for better foreground bokeh, and
>you rarely see it in many photos either. Most of the time, bokeh is a
>background effect, and lenses are differentially optimized for background
>bokeh rather than foreground bokeh, so you can't know about background
>bokeh by testing foreground bokeh, as I did in this test.
Fine, if you only want to test background bokeh that's fine w/ me as I agree,
background bokeh is usually used in more/most? portrait shots, though having
said this, its still pretty easy to take a small tree limb w/ leaves that's
been blown to the ground and attach it via some tape/cord to a chair/light
stand in the foreground about a foot or two away from the camera so it will
become your outof focus foreground element when your camera is focused on your
subject at about 4 1/2 feet away. But its your call/foreground tree limb ;-).
>Proposed Bokeh Test:
>
>Luis Lopez Penabad has provided an example of bokeh testing and bad bokeh
>from a zoom lens at the top of my bokeh page at
>http://medfmt.8k.com/mf/bokeh.html
I've seen it. Canon 28-105 zoom, bokeh sucks ;-)
>I am thinking that what I need to do is find a similar situation, with a
>background of leaves and trees which provides lots of background
>highlights in a range of sizes, as in his example.
Yup :-).
Be sure to include an area that not only has tree leaves and branches but small
spaces between the leaves that let the bright skylight through that will form
out of focus circles/donuts whatever shaped hilights.
>I am not sure if it matters what the subject is (?), so it might be
>possible to use a person (in a chair) at a fixed distance (tape measured
>as you suggest from tripod?, verified in viewfinder?).
Just do your best job at measuring focus either w/ measuring tape from the
subject to the film plane marking on the camera, or, if you have decent
eyesight and/or a viewfinder magnifier, focus by eye back and forth (through
the point of focus) until you get the sweet spot (catchlights in the eye or the
iris of the eyes) in focus. Just make sure the subject stays put w/ their head
position and doesn't lean forward as some subjects might unconsiously do during
the course of the test. Back straight against the chair should be your/their
motto before each exposure of the test ;-).
Unless you're/others doing macro photography of flowers, insects, whatever, the
most common use of bokeh effects would be in the blurred backgrounds of
portrait shots, so yes, _please_ _do include a _person_ in a chair_, it will
aslo show us how that person pos and relates to the out of focus background
bokeh.
>I am not sure that 4-5 feet is the optimal distance for the subject, but
>it probably doesn't matter in a background bokeh test? ;-)
I hope you are jokng here. It matters absolutely. What's the point of bokeh
test unless you have some kind of bokeh effect to show - a closer focusing
distance will ensure a nice/observable out of focus background bokeh effect
(especially when the background is about 15 feet or more behind the person as
well/
Even if the
>subject is slightly out of focus, it is the background bokeh we are
>assessing in a bokeh test. It might be better to shoot at 8-10 feet, so as
>to avoid issues with closeup performance and provide convenient working
>distance?
Absolutely not! You are trying to observe bokeh effects/qualities. By backing
away in your camera to subject distance you are sabotaging the very effect you
are trying to create/observe. This is "optical suicide" for a bokeh test. If
anything you want to get closer to the subject in a bokeh test to ensure that
the background will ber rendered suitably out of focus.
The other reason is practical, since most of us don't shoot a
>lot from 4 feet or 5 feet, but more often 8-10 feet with the 50mm lens,
>yes?
No, at least not me. Seriously Bob, are you afraid of getting too close to your
subject? There is no point in doing a bokeh test from 8-10 feet away from your
subject w/ a 50mm lens as there will be little bokeh to test. If you are going
to do the test from this distance you might as well save the money you would
have spent on this test's film/developing and put it towards something more
worthwhile like a good meal. At 8-10 feet you are getting nearly a full head to
feet shot w/ a 50mm lens. Portraits that have bokeh as an important factor w/ a
50mm lens (as opposed to the 85-135mm lenses used for tight head shots which
have nothing but too much bokeh/total blur to test at closer 3-5 foot
distances) need to be shot from closer distances than 8-10 feet, 4-5 feet is
adequate for a camera to subject distance to show background bokeh effects w/ a
50mm lens at or near wide open, w/ 4 feet being better as it would blur out the
background even more. (Camera to subject) Distance does count in bokeh! Don't
try to get away with anything over 4-5 feet as it will make the test sort of
pointless.
Again, someone could do a test using a range of distances and
>f/stops, as well as subjects and backgrounds, but the number of shots
>quickly expands hugely when you start to make 6-12+ sets for mailing out
>;-)
>
That's why I suggest the 4-5 feet range as being a good compromise between
closeness and distance and adequateyl being able to show b.g. oof effects when
a 50mm lens is used wide open.
>Again, it may take some experimenting to figure out which f/stops are most
>needed for such a test? Obviously, we expect the wide open shots to have
>the most interesting and "best" bokeh. But I would also like to know how
>much stopping down impacts the bokeh effect? Perhaps an wide open shot
>(f/1.4, f/1.7 or f/1.8?), f/2, f/2.8, f/5.6, f/8, f/16 for 6 shots each
>on
>a roll of 36 exposure slides?
>
There is effectively no (very little) bokeh effects to speak of at f/16, f/8 is
kind of pointless to unless you are going to be shooting from very close up.
Plus, most slide pages that I know of are 5 images across, not 6. So a good
sequence might be wide open (f/1.4, f/1.7 or f/1.8?), f/2, f/2.8, f/4, f/5.6 on
a 50mm lens at about 4-5 feet (or 4 1/2 feet to split the difference ;-)) from
the subject and a background that is at least 15 feet or more (more distance
(of any amount pof feet past 15 feet) from the subject to the background is
preferable, but that will depend on your location).
>I do disagree in believing that it is useful or needed to keep the same
>subject and lighting and background in such a test, to maximize the value
>of the test. It is just hard to compare different lenses.
>
Well what can I say, other than to me, it makes sense to keep as many variables
equal/similar as possible, that way we can focus (pardon the pun) on the one
thing that counts here, bokeh effects. Also, shooting bokeh tests under
different lightings (overcast vs. direct sunlight) will introduce other
complications that you definitely don't want in judging bokeh (like extra
highlights in the scene from reflections off of the leaves and other shiny
surfaces in the bright direct sunlight that won't be there on the overcast
shots). Its better to do the test right and keep all your parameters the same.
If this means even having to put off the bokeh test until you can do it under
the same lighting conditions for the same subject, then it will be worth the
wait because at least you will be testing the bokeh of the lenses and not the
bokeh effects introduced by the lighting conditions. Doing bokeh tests under
different lighting conditions is really the equivalent of doing two differnt
bokeh tests and comparing bokeh apples w/ bokeh oranges. There are better ways
to make fruit salads (a mess) w/o going to the time and trouble of doing it on
film ;-). Also, as an added plus, for those interested in portraiture/people
shots, it will be nice to see how, _under the same lighitng conditions_, each
lens will render not just the bokeh but the subject's skin tone, color
saturation of clothes, hair texture, etc.
>To make this a blind preference free test, we could group the shots
>together, so a single slide binder would have 36 shots, each row of 6
>shots from one lens,
Just occured to me, you say 6 shots, are you planning to put the slides into a
negative page _uncut_ and non-mounted?, then your mentioning of 6 slides makes
sense. For mounted slides it would be either 5 or 4 across, depending on how
one orients the slide page...
each labeled with a random number and f/stop label.
>You could easily compare six lenses at a time on each sheet for bokeh
>effects down the page, by f/stops across the page. Users would rate the
>bokeh from best to worst (I can use non-parametric statistics here etc.)
>
>in any case, something to think about, probably means I need more film ;-)
>
>grins bobm
Definitely more film ;-)
You could do several sets of ratings for more detail (I guess "more detail" is
a pun in a bokeh test ;-)):
Best to worse bokeh (you could do numbers but I would probably do the lens
brands coded in letters) ie.
From best to worse Bokeh (1. being the best bokeh lens and 5. (or the number
for however many lenses you are testing put here - if there are 7 lenses then
you would list them 1-7 from best bokeh lens to worse)). Best f/stops for best
bokeh w/i each brand of lens would be in parentheses from best* (left) to worse
(right) w/i parentheses to the right of each brand/letter code.
*Note, "best" bokeh (though obviously being a subject determination) does not
necessarily mean the shot w/ the seemingly most out of focus background but the
background w/ the most pleasing light distribution w/i the out of focus blur
circle (either a light center that fades off/darkens around the edges of the
blur circle or an even light distribution from the center to the edge of the
oof blur circles would be considered good/pleasing bokeh whereas oof blur
circle hilights that have either dark centers or lit centers but much brighter
edges (known as "ringing" or "donut" shaped light distribution would be
considered "bad"), least line de-doubling of the edges of branches/buildings or
other straight edged objects would be considered "good"/best, least deformation
of the oof coc due to internal vignetting and/or coma (ie. when oof circular
highlights are turned from circles into other shapes such as "footballs"/oblong
or elliptical circles (due to internal vignetting) and/or "bird wings or "v"
shaped highlights (normally due to coma) would also be considereed "good"/best
bokeh. For example: Brand C, listed as the best overall lens for good bokeh
below (this "C" is a code and C could just as easily stand for Leica or Pentax
or Minolta or Nikon instead of Canon) might have the _blurriest_ background
bokeh at f/1.4 (wide open) but might have the _best_ background bokeh at f/2.8
due to the lack of artefacts/abberations such as coma, internal vignetting,
cohesion of image detail w/i the blurred areas, most pleasing overall blur
effect, etc.
An equal sign next to/left of the f/ stop number in the parentheses means that
the rater thinks that that f/ stop has equally pleaing/unpleasing bokeh as the
f/stop to the left of it. For example: In the case of Brand "C", the rater
rates both f/2.8 and f/4 having equally good/pleasing bokeh and f/5.6 and f/1.4
as having the worse bokeh w/i that lens brand (Brand "C").
You might also have a separate comments section as to what each person thought
of each row (same brand lens) of the bokeh at different apertures (what were
the observable bokeh effects ie. light distribution w/i the coc, shape of the
oof coc blur circles at center and edges of the frame, any double lining of
branches/edges, integrity/cohesion of observable detail in the oof middleground
and backround areas, overall pleasantness/beauty unpleasantness/ugliness of the
bokeh effects):
1. Brand C (Best bokeh lens of all brands) ((Best bokeh f/stop) f/2.8, =f/4,
f/2, f/5.6, =f/1.4 (Worse bokeh f/stop w/i this brand of lens)
Comments: I considered f/2.8 and f/4 to have equally pleasing bokeh with high
image cohesion (details w/i out of focus areas in both the middle and
backgrounds) were easily readable/identifiable), no line de-doubling of tree
branches, evenly illuminated blur circle shapes hilights in the
background/spaces between the leaves of the trees that showed skylight, etc.
f/1.4 had massive gull winging towards the edges and very slight bright ringing
but otherwise was still very pleasing in effect w/ not as much image cohesion
as f/2/ or f/4 and just a slight hint of line dedoubling of the tree branches,
which, though not obtrusive or overly harmful to the appeal of the background
bokeh and overall image, were still "there" and readily observed.
2. Brand A (5 f/stops listed from best to worse bokeh)
Comments: (blah, blah, blaaaaaaaaaaaahhhhhhhhh......)
3. Brand D (5 f/stops listed from best to worse bokeh)
Comments: (blah, blah, blaaaaaaaaaaaahhhhhhhhh......)
4. Brand E (5 f/stops listed from best to worse bokeh)
Comments: (blah, blah, blaaaaaaaaaaaahhhhhhhhh......)
5. Brand B (Worse Bokeh lens of all brands) (5 f/stops listed from best to
worse bokeh)
Comments: "Land of the Donuts" - A haven for Homer Simpson at every aperture
except f/5.6. Massive amounts of line dedoubling, looks like an earthquake or
one of those 3d super imposed image comic books ;-). Are you sure this isn't
Luis Lopez Penabad's Canon 28-105 EOS zoom ;-)? Ok, which distorted bottom of a
CokeT bottle was this lens cut from?
**I've only listed bokeh comments for the best and worse brand 50mm lenses both
to save on typing and because extra comments are optional.
***It might be good to put a detailed object in back of the subject (the
"middleground") to the subject's left or right slightly to show image
cohesion/clarity of detail w/i the slightly to moderately out of focus area in
the distance behind the subject, because, in shots showing two or more people
(candid or posed group shots portraits, closer made theatrical shots) at
different distances where one person, in the foreground, stands out in sharp
relief to a slightly blurrier person behind them (or in cases where portraits
are made w/ pieces of the environment behind/around the subject are shown
slightly blurrier (not in focus but not completely out of focus either) than
the subject, "image cohesion" affects the overall aesthetics of the
pleasingness of the image. You wouldn't have to use two people to show image
cohesion (I don't want you to have to do a casting cal, one real live person as
the subject is enough), just set up something (an object w/ detail like a
statue or a map or a dog (one who like s to sleep a lot and doesn't move), a
stuffed animal or doll???/you decide) in the middleground (or put objects at
various distances behind the subject to show image cohesion/bokeh effects from
the in focus subject area to the out of focus background) two feet behind the
subject (...also 5 feet behind the subject, ... also 7 feet behind the subject
- for multiple detailed objects in the middleground to show image cohesion
effects). Some of your detailed subjects could have shiny/reflective surfaces
(porcelain? statuettes/something else?) thatcould reflect other coc in the
middle distances to show how this is affected from the mddleground out further
into the background. Just a thought...
Once you have a "set up" (scene) then all you have to do is shoot them all w/
the same scene. Its more complex in writing than it would be to set up in
reality. Hopefully ;-). No, seriously, just have a camera on a tripod w/ 50mm
lens focused on a person sitting in a chair 4 1/2 feet away from the camera w/
various detailed objects at different distances behind that person and tree
leaves/branches in the distance 15 or (preferrably) more (30?/50?) feet away
with enough space inbetween the leaves to allow the sky behind them to show
through and make some nice "discs" (out of focus blur circles/circles of
confusion/"coc").
Regards and may all your bokeh be good bokeh ;-),
Lewis
P.S.- Take/keep good notes - ...unless you want to test all normal lenses from
the same brand ;-)
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: rmonagha@engr.smu.edu (Bob Monaghan)
Newsgroups: rec.photo.equipment.35mm
Subject: blind 35mm lens tests - was Re: Pentax Lens Bokeh
Date: 29 Nov 2003
re: flare test I can't recall exactly which book by Roger Hicks and
Frances Schultz, I have a number of their books too ;-), but I suspect it
was The Lens Book, which describes their go/no-go lens testing, using a
single roll of film, to assess flare, resolution etc. The black branches
or power lines against the bright sky is a rigorous test for veiling glare
type flare; you can also shoot into the sun or better yet at night with
bright light source to really see how lens handles flare, effects of
stopping down, and so on ;-) I also like that this real world test gets
around critics who carp that lens test chart testing is not real world ;-)
re: disappointment with bokeh tests
the highlights off the fountain show some interesting differences, with
some lenses yielding more "colorful" patterns (at high loupe powers) from
some kind of prismatic effect(?), but I realized that I was missing out on
the really important bokeh info. I tested the effects of foreground
highlights, but few lenses are optimized for better foreground bokeh, and
you rarely see it in many photos either. Most of the time, bokeh is a
background effect, and lenses are differentially optimized for background
bokeh rather than foreground bokeh, so you can't know about background
bokeh by testing foreground bokeh, as I did in this test.
Proposed Bokeh Test:
Luis Lopez Penabad has provided an example of bokeh testing and bad bokeh
from a zoom lens at the top of my bokeh page at
http://medfmt.8k.com/mf/bokeh.html
I am thinking that what I need to do is find a similar situation, with a
background of leaves and trees which provides lots of background
highlights in a range of sizes, as in his example.
I am not sure if it matters what the subject is (?), so it might be
possible to use a person (in a chair) at a fixed distance (tape measured
as you suggest from tripod?, verified in viewfinder?).
I am not sure that 4-5 feet is the optimal distance for the subject, but
it probably doesn't matter in a background bokeh test? ;-) Even if the
subject is slightly out of focus, it is the background bokeh we are
assessing in a bokeh test. It might be better to shoot at 8-10 feet, so as
to avoid issues with closeup performance and provide convenient working
distance? The other reason is practical, since most of us don't shoot a
lot from 4 feet or 5 feet, but more often 8-10 feet with the 50mm lens,
yes? Again, someone could do a test using a range of distances and
f/stops, as well as subjects and backgrounds, but the number of shots
quickly expands hugely when you start to make 6-12+ sets for mailing out
;-)
Again, it may take some experimenting to figure out which f/stops are most
needed for such a test? Obviously, we expect the wide open shots to have
the most interesting and "best" bokeh. But I would also like to know how
much stopping down impacts the bokeh effect? Perhaps an wide open shot
(f/1.4, f/1.7 or f/1.8?), f/2, f/2.8, f/5.6, f/8, f/16 for 6 shots each on
a roll of 36 exposure slides?
I do disagree in believing that it is useful or needed to keep the same
subject and lighting and background in such a test, to maximize the value
of the test. It is just hard to compare different lenses.
To make this a blind preference free test, we could group the shots
together, so a single slide binder would have 36 shots, each row of 6
shots from one lens, each labeled with a random number and f/stop label.
You could easily compare six lenses at a time on each sheet for bokeh
effects down the page, by f/stops across the page. Users would rate the
bokeh from best to worst (I can use non-parametric statistics here etc.)
in any case, something to think about, probably means I need more film ;-)
grins bobm
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 28 Nov 2003
Subject: Re: Pentax Lens Bokeh
...
I'm not Bill, but... :-)
Have you considered doing some bokeh tests at wide open (f/1.4) or f/2 (if
doing a mix of f/1.4 and f/1.8 and f/2 lenses) w/ a subject (a person?) about 4
or 5 feet away from the camera and a background 12 or more feet away from the
background that would include some branches (to test line dedoubling), folliage
w/ leaves (or pine needles or whatever) and other things with either details
and/or colors in the background to test background bokeh) and a foreground
object (more leaves) out of focus about 1-2 feet away from the camera to test
foreground bokeh.
Just a thought/suggestion... :-)
Regards and Happy Thanksgiving,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 26 Nov 2003
Organization: AOL http://www.aol.com
Subject: Re: Pentax Lens Bokeh
Hi Bob :-):
>Subject: Re: Pentax Lens Bokeh
>From: rmonagha@engr.smu.edu (Bob Monaghan)
>Date: Tue, Nov 25, 2003
>
>Hi Lewis!
>
>see http://medfmt.8k.com/mf/blindresults.html (and blind.html and
>blindtest.html for proposal and rationale for blind/double-blind lens
>testing). These are for medium format lenses, ranging from zeiss planar on
>rolleiflex to hasselblad zeiss lenses to bronica nikkors and kowa pro
>lenses down to chinese DF4 pilot $75 6x6cm SLR for the low end. After you
>pull out the three element lens models, the others give such close
>performance that I and most others can't reliably tell them apart. This
>has been an interesting learning experience for me and others out there
>too! ;-)
>
>I am planning on repeating this experiment using a variety of 50mm lenses,
>including a leica summicron, minolta f/1.7, nikon f/1.8 and f/1.4,
>pentax 50mm, contax/yashica, topcon, and other models with side by side
>shots of the same subject, same lighting, same tripod, same film, same
>processing, possibly this vacation if we get a spell of good weather ;-)
>I will be quite interested to see if 35mm users can tell apart those
>slides by the brand of lens that took the images ;-)
>
Sounds like a great idea, let us know if/when you have an URL. Might want to
try some shots w/ out of focus background for a bokeh check too :-)
>but given that there hasn't been any statistically significant differences
>after many volunteer tests on the high end multi-kilobuck lenses against
>the $100-ish used lenses, and even worse, the $100-ish Kowa 85mm and
>bronica nikkors have so far been the highest rated lenses over my zeiss
>rolleiflex and hasselblad lenses, I wouldn't want to bet the 35mm lenses
>will be any easier to split out by brands ;-)
>
>grins bobm
The results from a Bronica Nikkor MF lens (S2? vintage) was exquisitely sharp
w/ nice color saturation, but I saw this years ago and am remembering from
memory.
I don't know how easy or hard it will be able to tell differences over the web
(the great leveler?) not only in sharpness but in color rendition, bokeh,
flare, micro-contrast, etc. though I have usually (but not always) been able to
pick out Leica lenses. It is much easier for me to do the selection on a light
table with a good loupe but that's kinf of hard to do over the internet ;-) and
I have an ancient machine in which even 100K images are (almost too) large
files ;-) ;-).
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 08 Dec 2003
Subject: Re: blind 35mm lens tests
Hi Gordon/Bob:
Gordon, I respectfully disagree w/ some of your statements (that is, if I'm
reading you correctly on your suggestions for a 50mm portrait bokeh test(s))...
>Subject: Re: blind 35mm lens tests
>From: Gordon Moat moat@attglobal.net
>Date: Mon, Dec 8, 2003
>Bob Monaghan wrote:
>
>> Thanks for some good points and ideas for tests ;-)
>>
>> We may need a suite of tests, perhaps a repeatable test for direct
>> comparisons (fixed night array, as you may be suggesting?) and a
>> subjective typical subject series as Lewis wants?
>
>I think the night idea works better,
I don't. People tend to photograph portraits more in the daylight than at
night.
>since it is easier to get the lens to
>wide open without introducing an ND filter, or needing a camera body with
>really high shutter speed.
W/ ISO 100 slide film on an overcast day you don't need an ND or a really high
shutter speed.
I photograph at night too, but I don't think we should forsake a daylight bokeh
test in exchange for a night-time one. Do both tests, Bob. I actually think a
daylight test is all you need but am wiling to agree to both a separate day and
night time tests if night time bokeh is so important to Gordon/others. You have
to understand where we're coming from. Gordon does (or has done) a lot of
night-time photography in clubs and I prefer to do daylight portraiture under
overcast/etc. conditions though I have done some night time photography (my
work is in the book "NIGHT SHOTS" in Rotovisions Pro-Lighting Series books) but
not a lot of portraiture at night ;-). To each their own...
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
Date: Mon, 08 Dec 2003
From: Gordon Moat moat@attglobal.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: blind 35mm lens tests
Bob Monaghan wrote:
> Thanks for some good points and ideas for tests ;-)
>
> We may need a suite of tests, perhaps a repeatable test for direct
> comparisons (fixed night array, as you may be suggesting?) and a
> subjective typical subject series as Lewis wants?
I think the night idea works better, since it is easier to get the lens to
wide open without introducing an ND filter, or needing a camera body with
really high shutter speed.
> I can't recall anyone linking bokeh at macro distances with bokeh
> performance at infinity, I would think lots of lens design issues might
> intervene (i.e., maybe a lens where the entire lens moved (zeiss planar?)
> would work, but a lens where element distances are varied, such as wide
> angles with closeup corrections (nikon 24mm CRC..) might be problematic?).
I don't know of any 50 mm lenses that have close range correction, unless
perhaps some of the macro lenses were built that way. Since more
photographers would likely stick to longer lenses to get defocus effects, and
mostly only wide angle lenses with CRC, I don't see that as a barrier to the
test. However, an extension tube might introduce some other effect, or
amplify some aberration.
> I am interested in testing some lenses to see how the bokeh varies with
> sample variation; I think I have 2 or 3 50mm f/1.4 nikkors I can use and
> ditto 105mm f/2.5 etc.
>
> I am in agreement about the 50mm f/2 nikkor; it is also perhaps the best
> for macro work, and may well be the sharpest as well as cheapest of the
> normal lens series to boot ;-) Again, this would be part of my interest.
Interesting that after posting the other message, I was looking at a couple
Zeiss Planar designs. One was the Contax 80 mm f2.0 for their 645, and the
other was the 80 mm for the Rollei 6000. In the link I posted, Nikon called
their design a Double Gauss, but when I looked at the layout again, it is
really more similar appearing to a Planar. In fact, the performance seems to
indicate it being more like a Planar, though perhaps Nikon did not want to
step on any Zeiss toes. :-/
> I am wondering if Brian Coldwell's optical design software has enough
> library lens designs, and the ability to project bokeh effects, to perhaps
> provide an alternative approach too? Then the issue might be finding a
> real world lens that performs as the designer intended? ;-)
Just sounds more like a sample variation, or quality control test. However,
starting with a good design seems to indicate a possibly good end result.
Some qualities that produce nice defocus areas are not the best choices when
absolute sharpness is desired across the film plane.
> but in the end, we are going to have to test these lenses for bokeh
> effects if that is what we value, and that is part of the reason to think
> this holiday season about how to setup such a test. I also think there is
> merit in moving away from concern about lens resolution alone to other
> factors like bokeh that can also impact image formation notably ;-)
>
> regards bobm
Except for architectural photography, but how much of that drives lenses
choices? I have some just for that, since I had a few big contracts in the
past that were strictly architectural photography, but my tendency is to
shoot more wide open, and intentionally get results with lots of defocus
areas. I definitely think there is an interest, but the actual defocus
rendition can still be a matter of tastes, and not something easily defined
for agreements.
Ciao!
Gordon Moat
Alliance Graphique Studio
http://www.allgstudio.com
From: brianc1959@aol.com (brian)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Fewer elements - lesser Bokeh?
Date: 30 Mar 2004
nicholas NpOoSoPzAlMed@yahoo.co.nz wrote
> brian wrote:
> >>So, my conclusion is that all Xenotar-type lens designs
> >>have this particular rendering...
> >
> >
> >
> > I'm going to assume that Xenotar means double-Gauss.
>
> Not quite... A Xenotar-type design is 5/4 and not symmetrical as you
> have me believe...
_SNIP_
Nicholas:
Double-Gauss designs come in a very wide variety of subtypes, and it
wasn't clear to me whether you were referring to the general design
form or to the particular 5/4 subtype. So, if you want to restrict
the conversation to the 5/4 type, then its OK with me. Xenotars have
a degree of symmetry very similar to other double-Gauss designs.
The fact remains: a 5/4 Xenotar subtype need not have harsh bokeh.
The reason for this is that the design flexibility is nearly as great
as with the more complex double-Gauss forms. A competent lens
designer can vary the character of the defocused background highlights
at will. For example U.S. Patent 2,844,072 by Lowenthal discloses an
f/2.8 Xenotar type lens with moderate undercorrected spherical
aberration. This design will produce beautifully soft-edged defocused
background highlights.
Although Schneider adopted the Xenotar type fairly early, the design
was pioneered by Charles Wynne of Wray Optical back in the 1940's. At
the time it was hailed as a significant achievement since it was
apparently simpler than the similar 6/4 Gauss type. Oddly enough, the
reason that the 5/4 Xenotar design form isn't used more widely is that
it is more difficult to make and hence more expensive than the more
common 6/4 form. The thickness tolerance on the 4th element almost
always turns out to be unusually tight, and this element is also quite
difficult to center.
The formula for the Vivitar Series I 90mm macro lens is given in U.S.
Patent 3,942,875 (example 6 of 6). There are a couple of minor typos
in the prescription, and I can give you the correct version if you're
interested. As you guessed, this design is not a Xenotar derivative
since the rear shell is a cemented doublet. However, changing that
cemented doublet to a singlet is easier than you might imagine.
Brian
www.caldwellphtographic.com
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Bokeh
Date: Fri, 06 Feb 2004
David Nebenzahl wrote:
> Stacey spake thus:
>
>> Both of the lenses you mention above
>> are probably sonar clones which almost always have wonderful bokeh.
>
> Yes; both the J-3 and J-8 are copies (very good ones) of the Sonnar. The
> J-3 is the fast one (f/1.5).
I figured as much.
>> Tssar lenses, while sharp have a sort of clumpy bokeh and some of the
>> sharpest lenses made in 35mm have 2 line bokeh which can be quite
>> distracting.
>
> What, pray tell, is "2-line bokeh"?
The first image on this page shows a double spire in the background (mirror
lens). That is an example of 2 line or double line bokeh. Nikor and many
other japanese lenses, especially their fast tele lenses, are known for
this "defect". Some people love the sharpness these have but the background
blur can be distracting if the wrong types of things are in the background.
http://www.trenholm.org/hmmerk/ATVB.pdf
Here are a few more articles on the subject.
http://www.kenrockwell.com/tech/bokeh.htm
http://hobbymaker.narod.ru/English/Articles/bokeh_eng.htm
http://www.luminous-landscape.com/essays/bokeh.shtml
On my Kiev lenses, the 250mm telear is a VERY sharp lens but has harsh
bokeh. Care must be used to keep -lines- out of the background as they look
awful if they are rendered too out of focus. Something like a sonar doesn't
have this problem.
One thing can be said for harsh lenses, they can appear to have deeper DOF
than a smooth bokeh lens like a sonar. Depending on what you are trying to
do with an image this can either be a plus or minus. When I use the 250
telear, I'm ussually wanting more DOF than the lens should produce so this
harshness can help. I think many LF lenses are like this and it does help
more of the image appear to be within acceptable sharpness, but produce
ugly images shot wide open.
I've been playing with shooting my 8X10 wide open and it's hard to find a LF
lens that looks nice. I don't need sharpness making contact prints, I need
smooth bokeh. So far a very old heliar looks the best I've tried.
--
Stacey
From: Stacey fotocord@yahoo.com
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Tominon 127mm Doesn't Match Shutter?
Date: Fri, 06 Feb 2004
David Nebenzahl wrote:
> jjs spake thus:
>> David Nebenzahl
>
> By the way, some of my favorite SovCam lenses (35mm Leica mount) are
> spozed to have good bokeh: the Jupiter-8 and -3.
Probably why they are your favorites...
Most "classic" good lenses have great bokeh, lenses with harsh bokeh are the
ones no one ever raves about. Both of the lenses you mention above are
probably sonar clones which almost always have wonderful bokeh. Tssar
lenses, while sharp have a sort of clumpy bokeh and some of the sharpest
lenses made in 35mm have 2 line bokeh which can be quite distracting. There
are other lens designs whose bokeh isn't easily described but it does
exist.
An example of LF bokeh was with my 8X10, I wanted to play with some wide
open shooting with the 300mm f4.5 tessar that came with my camera and it
wasn't very pretty, I bought a voighlander heliar 300mm f4.5 and the wide
open shots with it were much more interesting. It was all about the out of
focus portions that differed. Yes it's a personal choice thing but if you
showed 10 people these 2 shots, I doubt anyone would pick the tessar ones
as being better.
--
Stacey
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 28 Nov 2003
Subject: Re: Pentax Lens Bokeh
Hi Bob :-):
>Subject: Re: Pentax Lens Bokeh
>From: rmonagha@engr.smu.edu (Bob Monaghan)
>Date: Thu, Nov 27, 2003
>
>yes, good idea, but hard to do in practice. Most 50mm lenses are setup and
>tested/aligned for infinity focus. The markings may or may not be accurate
>at 4 or 6 or 10 feet. Focusing by eye adds a subjective factor, which may
>not be repeatable, which could be more of an error source than the
>differences between many lenses.
Why not try it anyway, or if you want to be extra careful/anal, like me;-), use
a measuring tape from the film plane index mark on the camera to the subject
him/herself. And/or just use the 4-5 feet test as a test of bokeh rather than
ultimate subject sharpness. People/portraits tend to be done more in this range
than at infinity, and even though I know there are people who care for nothing
else other than infinity performance (landscape and astronomica/sky/weather
usages), a majority of people still shoot people pictures/portraits in this
closer range and I feel it would be a mistake to forego this distance just
because of difficulty in focusing. Perhaps there is some kind of eyepiece
magnifier that would allow you more precise focusing if you must know sharpness
down to the nth degree at this range in addition to portrait background bokeh
effects. But "don't get your knickers in a twist" about ultimate sharpness, I'd
rather see even slight focusing errors than no portrait/bokeh test in this
important 4-5 foot range.
>IIRC, a recent poster (Brian#### ?) noted that most lenses are not
>optimized for foreground bokeh but background bokeh, so perhaps a set of
>photos could be done to highlight background bokeh effects, which are more
>often an issue in any case?
Sounds fair enough, though including something out of focus in the foreground
is not really a big deal if both the tree branches in the foreground and the
tripod is steady which should be the case so long as there are no earthquakes
about ;-). I really don't think that including both foreground and background
bokeh elements in the same shot is such a big deal because once you've placed
the subject and positioned the camera to record it and the background and the
foreground leaves or whatever, the test conditions are set and wont have to be
changed from shot to shot.
>I tried to provide some foreground highlight/bokeh effects in my medium
>format blind lens tests by positioning a fountain in bright sunlight
>during the test shots in the foreground, to the side. See the sample photo
>at top of http://medfmt.8k.com/mf/blindtest.html for layout. But like my
>handholding test, this part of the experiment was a disappointment.
Why do you consider it a disappointment?
>Another test I'd like to run is Roger Hicks flare test - using branches or
>a set of power lines to see how well the lens splits bright and dark
>areas.
Sounds good. Is that test in Roger's book "35mm Panorama" or in some other
book?
>The problem with too many tests is that you end up with a very complex and
>intimidating test protocol ;-(
I agree, but what I suggested above is not as hard as you might think once all
elements are set in place. The foreground/background test would be at a common
near or at wide open aperture on all lenses (if all lenses were 1.4s you could
do the test at 1.4, if there is a mix of 1.4s and 1.8s and/or f/2s you could do
the test w/ all of them at f/2). I am not really asking for a full range of
bokeh f/stops just at wide open (or near there, depending on your wide open
apertures of your various lenses as just mentioned). If you feel inclined to do
f/2.8, f/4, and/or f/5.6 bokeh shots that would be your decision, but the bokeh
tests do not have to be sharpness tests too covering the whole range of
f/stops, neither do they even have to be of the same subject (or focusing
distance, since all bokeh at infinity is virtually the same ;-)) as your
sharpness tests.
You also end up burning a LOT of film, as
>you need 6 to 12 or more sets of each slide shot to be able to mail some
>out, esp. as some folks hang on to them to show their photo club friends
>or forget to return them ;-(
I empathize with your plight here, but the only way to get a good range of
opinions is to show many people. Perhpas you know enough photographers and/or
photographers who know photographers so the slides would either never have to
leave your house/whatever and/or you could take it with you to some nearby
photogrphers/friends residence so you can be assured of getting your prints
back before you leave. The other alternative is to both be a trusting soul and
to find people who will be trustable so you don't have the problem of
non-returns and/or tellthem that only they can see it and not their photo
clubs/whatever so there's no inbetween places/venues for the slides to get lost
at...
Unfortunately, I agree with you that this
>can't be done well on a monitor from film scans, so has to be the original
>slide film under study. ;-)
>
>regards bobm
>--
Sad, but true ;-).
I'm sure you already have a list of testers filled but if you don't, you might
want to add me to your list as I'd love to try my hand/eye at various brands'
lens' sharpness/bokeh signatures. Either way, let me/us know the results as I'd
love to know. And possibly post alink, if we can't see them in person, at least
guessing on the web may not be an accurate representation but at least it
should be fun ;-).
Regards/Happy Thanksgiving,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 28 Nov 2003
Subject: Re: Pentax Lens Bokeh
Hi Brian:
>Subject: Re: Pentax Lens Bokeh
>From: "rbwalsh" brian.walsh@e-mailanywhere.com
>Date: Thu, Nov 27, 2003
>
>"Lewis Lang" contaxman@aol.comnospam wrote...
>> Have you considered doing some bokeh tests at wide open (f/1.4) or f/2 (if
>> doing a mix of f/1.4 and f/1.8 and f/2 lenses) w/ a subject (a person?) about 4
>> or 5 feet away from the camera and a background 12 or more feet away from the
>> background that would include some branches (to test line dedoubling), folliage
>> w/ leaves (or pine needles or whatever) and other things with either details
>> and/or colors in the background to test background bokeh) and a foreground
>> object (more leaves) out of focus about 1-2 feet away from the camera to test
>> foreground bokeh.
>>
>> Just a thought/suggestion... :-)
>Snip, snip...
>
>Lewis has a good idea. When I read poor TP's vitriolic comments much earlier
>in the thread, I thought of this example (and thread) regarding the Leica's
>King of Boke(h):
>
>http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=004LWx
>
>Clearly, focal distance, aperture, etc., etc. play a role.
Thanks for the link, Brian, it was very interesting/informative. I still
maintain that the Pentax 31mm Ltd. lens is the best Leica lens for
bokeh/clarity that Leica never made ;-). I'd love to see even a 50mm bokeh
test. Funny, in the test they were complaining about the bright ringing, but I
've even found that to be a good attribute in some portraits I've taken
(strangely enough) so long as its in keeping with both the portrait/candid
subject/person, mood, situation, lighting, etc. I've also found my 50/1.8
Series E nikon to have variable bokeh (ultra smooth bokeh in overcast light w/
little background image coherence (complex bokeh which supresses background
details and makes the b.g. details seem even more out of focus than normal,
pooping out the subject)- the exact oppositte look of a Leica lens which pride
themselves, annd rightfully so on image coherence as a big factor in their
bokeh look, especially in lenses like the last 35mm f/2 M Summicron version 4
and the 75/1.4 M lens, and in backlit trees oof highlights/coc circles showing
up as somewhat ringed (but not overly "donutty" background highlights which I
strangely enough also find very appealing w/ the right subject - not that I
would pass up a smooth more coherent 35mm f/2 M v4 or 75/1.4 M if somebody gave
me those ;-)).
Regards and Happy Thanksgiving,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 03 Dec 2003
Subject: Re: blind 35mm lens tests
>Subject: Re: blind 35mm lens tests
>From: rmonagha@engr.smu.edu (Bob Monaghan)
>Date: Tue, Dec 2, 2003
>
>Hi Chris, thanks for the shared info and test page URL resources!! I am
>still looking for an ideal and close site. One other possibility I am
>going to explore is seasonal, namely, Xmas tree lights as bright light
>point sources which would be reproducible and comparable, though
>brightness might be problematic? ;-) Maybe I can use a Santa figure for
>the subject too ;-) ;-)
SNIP
Hi Bob:
Please, oh, please say you're joking, Bob. Such a test might make Mrs. Santa
very happy but it would only show the bokeh of bright tiny point sources on a
subject that's about as human as Bart Simpson w/ only a slightly better
complexion ;-). Seriously, though, better to postpone the test till Spring (w/
real tree leaves and spaces between the of bright sky like in a real portrait,
not like the "Bokeh Nightmare Before christmas", than to do a portrait bokeh
test where neither the subject or the background resembles any kind of "normal"
portrait elements. (And this is from a person who detests/is the antitheses of
"normal"). How many portraits on average do you usually shoot that have tens or
hundreds of tiny little point sources inthe background? I am not ungrateful for
what you're doing, just the oppositte - but a portrait bokeh test w/ a Santa
statue/figure and Christmas lights sends chills up and down my spine (though
I'm sure many an elf w/ superior Leica gear and a superiority complex would
love to see the results). Human. Trees. Sky through Leaves. No bokus pokus
bogus shortcuts. No "Ho Ho Bokeho Yoko" P-L-EEEEEEEEEEEEEEEEE-A-S-E. Thanks.
My Bokeh Nightmare (50mm f/2 Leica R, focused roughly at about 6-8 feet, about
f/16 or so and all its missing are some Christmas lights to complete the
nightmare ;-)):
http://members.aol.com/Lewisvisn2/st9.htm "MONA SANTA"
Santa? Bah Humbug!
Santa Bokeh? Bah Hokehm!
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: Christoph Breitkopf chris@chr-breitkopf.de
Newsgroups: rec.photo.equipment.35mm
Subject: Re: blind 35mm lens tests
Date: 03 Dec 2003
rmonagha@engr.smu.edu (Bob Monaghan) writes:
> Hi Chris, thanks for the shared info and test page URL resources!! I am
> still looking for an ideal and close site. One other possibility I am
> going to explore is seasonal, namely, Xmas tree lights as bright light
> point sources which would be reproducible and comparable, though
> brightness might be problematic? ;-)
Hmm, I think the higher the contrast, the easier to judge
the light distribution within the circle of confusion.
Exposing for the highlights should show this nicely.
Of course, given the color temperature of christmas tree
lights, I'd guess the circles might come out mostly
orange on daylight balanced film. ;-)
Regards,
Chris
--
Bokeh test images: http://www.bokeh.de/en/bokeh_images.html
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 02 Dec 2003
Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
>Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
>From: Christoph Breitkopf chris@chr-breitkopf.de
>Date: Tue, Dec 2, 2003
>Hello Lewis,
>
>contaxman@aol.comnospam (Lewis Lang) writes:
>> I've been to your site before and enjoyed it. I am still a fan of the 4 1/2 to
>> 5 foot lens focusing distance for people shots because even when there are
>> trees in the background that you would like to see out of focus blur
>> circles/coc of, setting the lens at 15x focal length (50mm which equals 2
>> inches) would give a 2 1/2 foot (15 x 2 inches = 30 inches which = 2 1/2
>> feet) focusing distance - not too close for me, but closer than possibly the
>> majority of amatures and perhaps some pros would get for their people shots.
>> This (2 1/2 foot camera to subject distance) would be a semi-tight head and
>
>Yep, it's a tight portrait distance for any focal length. Of
>course, a tight portrait with a 20mm lens (or even 50, as you note)
>looks kind of funny.
>
>> shoulders shot w/ a 50mm lens - too close perspective-wise for most people that
>> don't have flat faces (or flat noses in particular) ;-). 8-10 feet as Bob
>> suggested wouldn't give enough bokeh w/ a 50mm lens even wide open at about
>> f/2. I feel that about 4/12 feet or so would be just right for a normalesque
>> people shooting distance/crop/perspective - sort of like Goldilocks and the
>> three bears w/ their porridge - "...and this bokeh was juuuuuuust right" ;-). I
>> realise that you weren't aiming for a portrait/people aspect in your tests,
>> Chris, but I just thought I'd rebring up this issue as I feel it is important
>-
>> different bokeh distances are best for different bokeh uses, even when they
>> include the same type of background (tree folliage w/ spaces for the sky in the
>> leaves to form blur circles).
>
>I agree, but you have to limit yourself, or you get just too
>many possibilies. Also, while you'd normally choose a slightly
>longer focal length for tight portraits, there is still some
>leeway - 100 - 150mm say. And, just maybe if you had a
>problematic background, a harsh bokeh 135mm, and a smooth bokeh
>85mm lens, and must shoot a tight portrait, having these lenses
>compared at equal reproduction rations is a good think.
>
>The variation of the background distance is a bit more artificial,
>I admit - not something you'd do in a real shot. However, keeping
>it at the same distance gived a huge advantage to longer focal
>lengths. If the tests included only classical portrait focal
>lengths, this would not be a large problem, but since I like
>to include everything from fisheyes to long teles, there is
>really no other option.
>
>As with any lens test (or even more so) interpreting the results
>and determining if/how they apply to ones own shooting habits
>is really important. Taken at face value, 'tests' (such as mine)
>can easily be as misleading as they can be helpful.
>
>Regards,
>Chris
>--
>Bokeh test images: http://www.bokeh.de/en/bokeh_images.html
Hi Chris:
Just so you know, my suggestions/comments, though referencing your site, were
directed at Bob for his future 50mm portrait bokeh tests. My point was _for
him_ to shoot the 50mm bokeh portrait tests at about 4 1/2 feet, not for you to
do so. Also, all I wanted him to do was test the 50mm focal length (at
apertures from wide open to f/5.6) at that particular distance on a portrait
subject (person in chair) w/ objects in the foreground (1-3 feet in front of
the camera) and in the middleground (which would be an additional 2 1/2, 5, and
7 feet behind the subject (which is already at 4 1/2 feet from the camera) but
in front of the far off folliage background/tree leaves w/ sky blur circles) to
test out blur "transition"/cohesion/integrity of the more and more out of focus
objects (I believe I suggested potted plants to him on tables and/or chairs for
the foreground and middleground/behind the subject objects). Its hard to get
more specific or narrow w/ my parameters than this. :-)
I just appreciate Bob wanting to do the test and was giving him suggestions for
_his_ upcoming test, I wasn't trying to tell you (or suggest) how to run your
own website/tests on bokeh. Just trying to give Bob some helpful test to,
pardon the pun, "focus on the most important aspects of bokeh" in his portrait
50mm bokeh test to make it worthwhile.
I also appreciate what you did for bokeh testing and sharing your URL/results
with us.
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: "Bandicoot" "insert_handle_here"@techemail.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Pentax Lens Bokeh
Date: Fri, 5 Dec 2003
"Bob Monaghan" rmonagha@engr.smu.edu wrote
> Hi Peter,
>
> yes, it is an interesting idea; the problem is I suspect folks would
> readily see the cut film without perforations as on 35mm film and cheat
> and lump them together ;-)
What I meant was to use an adapter to fit the lens to a 35mm body - sorry I
wasn't clear enough. I see lots of adapters to fit P6 lenses (like the
Flek) to various 35mm bodies on *Bay, and I have a couple myself, one of
which allows me to use P6 lenses on my Pentax bodies with shift, taking
advantage of the bigger coverage.
> with medium format backs, I had to trim the image to the edges to cutoff
> the "hasselblad vees" and other markers which would enable folks to tell
> which camera took which photo from the back markings (see photo ads where
> the hasselblad Vees are shown - in photos taken for a bronica lens ad ;-)
> see http://medfmt.8k.com/mf/photoads.html ;-)
Yes, I've enjoyed that page before!
> I did study the issue of Med Fmt vs. LF and 35mm quality, concluded that
> 35mm is generally higher resolution as optimized for less coverage, but
> with enough $$ you can buy MF and LF lenses (Schneider..) which have such
> high resolution that they are as good as the 35mm ones. But you can buy a
> 35mm lens that is really good for $150 or so, while the LF version might
> be 15-20+ times that ;-) see http://medfmt.8k.com/mf/mfbest.html
That I can believe. I use Schneiders on my 6x9 technical camera, and a four
lens kit (from 47 to 180mm) is probably as much as I want to invest. I love
the Schneider 80/2.8 Xenotar I have for my Exacta 66, but in truth the
difference between this and the CZJ lenses is pretty slight (especially the
180/2.8, but then that is a very special lens.)
Cheers,
Peter
From: "Jeremy" jeremy@nospam.thanks.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Pentax Lens Bokeh
Date: Fri, 28 Nov 2003
"Bob Monaghan" rmonagha@engr.smu.edu wrote
> yes, good idea, but hard to do in practice. Most 50mm lenses are setup and
> tested/aligned for infinity focus. The markings may or may not be accurate
> at 4 or 6 or 10 feet. Focusing by eye adds a subjective factor, which may
> not be repeatable, which could be more of an error source than the
> differences between many lenses.
>
> IIRC, a recent poster (Brian#### ?) noted that most lenses are not
> optimized for foreground bokeh but background bokeh, so perhaps a set of
> photos could be done to highlight background bokeh effects, which are more
> often an issue in any case?
>
> I tried to provide some foreground highlight/bokeh effects in my medium
> format blind lens tests by positioning a fountain in bright sunlight
> during the test shots in the foreground, to the side. See the sample photo
> at top of http://medfmt.8k.com/mf/blindtest.html for layout. But like my
> handholding test, this part of the experiment was a disappointment.
>
> Another test I'd like to run is Roger Hicks flare test - using branches or
> a set of power lines to see how well the lens splits bright and dark
> areas.
>
> The problem with too many tests is that you end up with a very complex and
> intimidating test protocol ;-( You also end up burning a LOT of film, as
> you need 6 to 12 or more sets of each slide shot to be able to mail some
> out, esp. as some folks hang on to them to show their photo club friends
> or forget to return them ;-( Unfortunately, I agree with you that this
> can't be done well on a monitor from film scans, so has to be the original
> slide film under study. ;-)
At what point does it become a case of breaking it down to the ridiculous?
If I understand this correctly, most people cannot determine which lens took
which shot--especially when we are comparing normal lenses. BUT, perhaps we
can find some lenses that perform a tad better under carefully-controlled
situations, where the lighting conditions are within very specific
conditions.
Unless a particular photographer had very exacting requirements, how much
weight can be given to these "special conditions" tests? Should they
influence whether or not a particular lens is purchased (obviously, if money
is no object, then go ahead and buy whatever--but money usually IS a
factor).
Should the lowly Minolta photographer feel bad because he /she isn't
capturing images with a Zeiss or Leitz lens?
Several books I've read by photographers, including Ansel Adams and Brian
Bower (who shoots 35mm exclusively with Leica) have plainly said that
virtually all mainstream 35mm camera lenses are up to the job--that a good
photo is more the result of the photographer than the equipment.
Brian Bower uses Leica because of their superior fit and finish, and their
excellent track record of being able to take considerable stress without
failing. But Bower is a professional, that makes his living with his
lenses, and cannot afford to be in the field with lenses that don't hold
focus or that have elements that easily go out of alignment. I am merely a
weekend shooter, that would not subject his equipment to the kind of abuse
and wear that a professional would. Should I have the same concerns about
fit and finish as does a professional? I think not.
Methinks that all this comparison testing may be carrying things too far.
If I ever reach the pinnacle and shoot 50 rolls per day, as does T.P.,
perhaps I can afford to settle for only the best. But I shoot more like 50
rolls a year. My equipment is babied, and looks almost new despite the fact
that most of it is 3 decades old.
From: Christoph Breitkopf chris@chr-breitkopf.de
Newsgroups: rec.photo.equipment.35mm
Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
Date: 02 Dec 2003
Hello Lewis,
contaxman@aol.comnospam (Lewis Lang) writes:
> I've been to your site before and enjoyed it. I am still a fan of the 4 1/2 to
> 5 foot lens focusing distance for people shots because even when there are
> trees in the background that you would like to see out of focus blur
> circles/coc of, setting the lens at 15x focal length (50mm which equals 2
> inches) would give a 2 1/2 foot (15 x 2 inches ='s 30 inches which ='s 2 1/2
> feet) focusing distance - not too close for me, but closer than possibly the
> majority of amatures and perhaps some pros would get for their people shots.
> This (2 1/2 foot camera to subject distance) would be a semi-tight head and
Yep, it's a tight portrait distance for any focal length. Of
course, a tight portrait with a 20mm lens (or even 50, as you note)
looks kind of funny.
> shoulders shot w/ a 50mm lens - too close perspective-wise for most people that
> don't have flat faces (or flat noses in particular) ;-). 8-10 feet as Bob
> suggested wouldn't give enough bokeh w/ a 50mm lens even wide open at about
> f/2. I feel that about 4/12 feet or so would be just right for a normalesque
> people shooting distance/crop/perspective - sort of like Goldilocks and the
> three bears w/ their porridge - "...and this bokeh was juuuuuuust right" ;-). I
> realise that you weren't aiming for a portrait/people aspect in your tests,
> Chris, but I just thought I'd rebring up this issue as I feel it is important -
> different bokeh distances are best for different bokeh uses, even when they
> include the same type of background (tree folliage w/ spaces for the sky in the
> leaves to form blur circles).
I agree, but you have to limit yourself, or you get just too
many possibilies. Also, while you'd normally choose a slightly
longer focal length for tight portraits, there is still some
leeway - 100 - 150mm say. And, just maybe if you had a
problematic background, a harsh bokeh 135mm, and a smooth bokeh
85mm lens, and must shoot a tight portrait, having these lenses
compared at equal reproduction rations is a good think.
The variation of the background distance is a bit more artificial,
I admit - not something you'd do in a real shot. However, keeping
it at the same distance gived a huge advantage to longer focal
lengths. If the tests included only classical portrait focal
lengths, this would not be a large problem, but since I like
to include everything from fisheyes to long teles, there is
really no other option.
As with any lens test (or even more so) interpreting the results
and determining if/how they apply to ones own shooting habits
is really important. Taken at face value, 'tests' (such as mine)
can easily be as misleading as they can be helpful.
Regards,
Chris
--
Bokeh test images: http://www.bokeh.de/en/bokeh_images.html
From: contaxman@aol.comnospam (Lewis Lang)
Newsgroups: rec.photo.equipment.35mm
Date: 02 Dec 2003
Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
...
Hi Chris:
I've been to your site before and enjoyed it. I am still a fan of the 4 1/2 to
5 foot lens focusing distance for people shots because even when there are
trees in the background that you would like to see out of focus blur
circles/coc of, setting the lens at 15x focal length (50mm which equals 2
inches) would give a 2 1/2 foot (15 x 2 inches ='s 30 inches which ='s 2 1/2
feet) focusing distance - not too close for me, but closer than possibly the
majority of amatures and perhaps some pros would get for their people shots.
This (2 1/2 foot camera to subject distance) would be a semi-tight head and
shoulders shot w/ a 50mm lens - too close perspective-wise for most people that
don't have flat faces (or flat noses in particular) ;-). 8-10 feet as Bob
suggested wouldn't give enough bokeh w/ a 50mm lens even wide open at about
f/2. I feel that about 4/12 feet or so would be just right for a normalesque
people shooting distance/crop/perspective - sort of like Goldilocks and the
three bears w/ their porridge - "...and this bokeh was juuuuuuust right" ;-). I
realise that you weren't aiming for a portrait/people aspect in your tests,
Chris, but I just thought I'd rebring up this issue as I feel it is important -
different bokeh distances are best for different bokeh uses, even when they
include the same type of background (tree folliage w/ spaces for the sky in the
leaves to form blur circles).
Regards,
Lewis
Check out my photos at "LEWISVISION":
http://members.aol.com/Lewisvisn/home.htm
From: Christoph Breitkopf chris@chr-breitkopf.de
Newsgroups: rec.photo.equipment.35mm
Subject: Re: blind 35mm lens tests - was Re: Pentax Lens Bokeh
Date: 01 Dec 2003
rmonagha@engr.smu.edu (Bob Monaghan) writes:
> The only big problem is that the dang trees around here
> are losing their leaves, so I have got to do some looking
They do that here too. Even if they don't lose them, they
change color, are shaking in the wind, and are hard to light
consistently (not owning a movie company, I have to rely
on the sun for light).
When starting out with bokeh test images (http://www.bokeh.de/en/),
I tried making a test pattern unsing a backlit black cardboard
with cut-out test shapes. Compared to trees, this has the
advantage of being excatly reproducible. Unfortunately this
has to be rather large for normal (non-macro) lenses to test
background bokeh. For most lenses the closes focus is about
10 times the focal length, and I've found that you need to
place the test pattern at least four times that distance to
get a large enough circle of confusion. That was too large
for my room and living partner ;-)
A darkened room with a few point light sources (LEDs perhaps)
might also work well.
So I used trees, too. I think to be able to compare lenses
of different focal lengths, the focusing distance and the
distance of the background need to be at fixed multiples
of the focal length. For my tree test shots, I usually
set the lens to 15x focal length, and try to find a tree
at about 50-100x focal length. Of course, sometimes I'm lazy.
And as noted the light and other factors change, so
the results are hard to compare. It's easy to spot really
bad lenses, but the large group of mostly neutral bokeh
lenses looks mostly identical.
Regards,
Chris
--
Bokeh test images: http://www.bokeh.de/en/bokeh_images.html
From: "Adam F" asfletch@uts.edu.au
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Flare: Leica Summicron R and Pentax Limited Lenses
Date: Sat, 29 Nov 2003
"Lewis Lang" contaxman@aol.comnospam wrote ...
> Hi Bob:
>
> Could you tell me which Minolta 50/1.7 has great bokeh, the MD (or earlier?) or
> the Maxxum A mount versions ((regular or D lens if there is a D lens made for
> this aperture now and not just the 50/1.4 D Maxxum A mount lens)? What has made
> you come to this conclusion, personal experience, comments on the web,
> something else? Any links to this 50/1.7 Minolta lens shot on (preferably) a
> person as subject at or near wide open that shows the bokeh effects of this
> lens?
>
> TIA
> Regards,
>
> Lewis
Don't think it'd be the Minolta-A 50/1.7 - much as I love this lens and use
it (never seen a sharper 35mm lens), its bokeh is not up to the standard of
the M42 pentax 50/1.4 or CZ C/Y 50/1.7 i also have - however the minolta MD
50/1.7 is supposed to be better in this regard, as is the M-A 50/1.4 with
the 55mm filter mount (redesigned circular aperture). For overall quality on
a budget I recommend a K-mount pentax 50/1.4 and a pentax MX or CZ 50/1.7 on
a contax RTS (~$150ea).
HTH
Adam F
From: "Bandicoot" "insert_handle_here"@techemail.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: minolta
Date: Fri, 5 Dec 2003
"Bob Monaghan" rmonagha@engr.smu.edu wrote
> yes, the portrait lenses are usually the most likely to be optimized for
> bokeh if the lens designers are thinking as photographers and not
> engineers (oops!) ;-) good pun on focusing on bokeh, aargh! ;-)
The reported differences between the Pentax A*85/1.4 and FA*85/1.4 seem to
illustrate this effect. The A* is a much admired portrait lens, and also
excellent at distance work, working fine for landscape (though few landscape
specialists need a 1.4 and will go with the 1.8 instead.) The FA* is liked
even better as a portrait lens due to the way the bokeh becoms 'creamy' very
quickly behind the plane of focus - the price for this seems to be that it
has less good distance performance.
In essence, the A* seems to have been designed to be a great lens, and being
an 85mm that included being a great portrait lens. The FA* seems to have
been designed specifically to be a great _portrait_ lens - lessening its all
round ability but making it even better in the people department.
I haven't compared the two myself, so freely admit that I'm reporting
hearsay - but these opinions seem widespread on these two lenses.
Peter
From: Yefei He [yhe@nads-sc.uiowa.edu]
Sent: Thu 5/6/2004
To: Lenses@topica.com
Subject: RE: [LENSES] Blur Circle (not bokeh) mapper
Joe,
Did you mention that you'd send a copy of the test version
program together with the source code to anyone interested? Does
that offer still stand or should I wait for the final version? As
I said I'm interested in it.
For those really into it, there's even a SIGGRAPH paper about
rendering bokeh on a computer:
http://www.flarg.com/bokeh.html
Darn I wish I had come up with a paper like this before them!
All I can do now is to supplement it to make Leica bokeh, Zeiss
bokeh, or Holga bokeh:-)
Yefei
> Date: Thu, 6 May 2004
> From: Joe Polizzi polizzi@westbend.net
> Subject: RE: Blur Circle mapper
>
> The reason we're not refering to bokeh is because bokeh really more
> refers to unique characteristics of the blur - usually caused by the
> effects of abberations in the lens design. In fact if I understand
> correctly, some lenses are intentionally designed with certain
> abberations UNDER-corrected, to make for more pleasing out-of-focus
> areas. We're leaving out those variables, so the blur circles that are
> calculated and described are rather 'perfect', generic, bokeh-less ones.
>
> Thanks for the resposes and help, guys!
>
> Joe
From: Fernando fcarello@tiscalinet.it
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: MF scanner upscaling? Re: MF future? Re: ideal cameras?
Date: Sun, 20 Jun 2004
Stacey fotocord@yahoo.com wrote:
>The "problem" with the vega 120 isn't the resolution (which it performs
>quite well), it's the bokeh. About as ugly as I've ever seen from any short
>tele lens! IMHO the 80mm arsat with a 1.4X converter is a much better
>option and cheaper. The 120mm biometar outperforms either.
Yes, if bokeh is more important for you than resolution and contrast;
I think it really depends of the type of photography one prefers.
I shoot mainly architecturals, and for me the superior (I'd say
"impressive") resolution and contrast of the Vega are more important
than bokeh; but of course for portraits, certain type of landscapes,
wildlife and the likes, a good bokeh is much more important than
resolving power.
This is the nice thing about having both the Vega 120 MC and the Arsat
80 MC + 1.4x MC teleconverter! And, they're so cheap! :-D
Fernando
[Ed. note: Fokeh? ;-) ]
Date: Fri, 19 Sep 2003
From: Zhang XK zhang_xiaokang@163.com
Subject: [Russiancamera] Bokeh related question
To: Russiancamera-user russiancamera-user@mail.beststuff.com
Hello everyone,
We had a very good discussion about the bokeh which is the background
highlight out of fucusing image quality. I read a booklet recently that
discussed not only the bokeh but the foreground out of focus high light
guality. Do we have a special word for it? Fokeh?
The interesting point is that a good lens should have not only good bokeh
but also good fokeh. A good bokeh and fokeh should have a soft edge and both
should have a similar shape which is an indication of good aberration
correction. If not, it is an indication of obvious residul spherical
aberation. And if they have different colors, then an indication of residul
chromatic aberration.Such a lens won't have a very high resolution.
This author's comparison of both bokeh and fokeh makes some sense to me. Has
anyone made such a bokeh and fokeh comparison on a FSU lens?
Best regards, now obsessed with technical questions
From: jimedbrowne@hotmail.com (Jim-Ed Browne)
Newsgroups: rec.photo.equipment.medium-format
Subject: Really Impressive Bokeh-Old Polaroid Lenses
Date: 24 Apr 2004
Check out the optics in the old rollfilm consumer Polaroids sometime.
I'm not sure what the best way to use them with a modern system camera
might be, but I've seen them put on small technical and press cameras.
I've also seen the 80mm or so front standard assenblies of the old
Pathfinders mounted on tubes for use with 35mm focal plane cameras.
They can be used then with aperture priority or by figuring out the
f-stops of the Waterhouse stops.
You want bokeh, there it is.
From: jimedbrowne@hotmail.com (Jim-Ed Browne)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: The Bokehmaster-my new invention
Date: 14 May 2004
> > At the most open stop the DOF is minimal and you can focus the camera
> >by the front surriound of the forward lens element. Objects in focus
> >are as sharp as they are going to get with a Coke-bottle lens-great
> >for Classic Portraiture-while out of focus objects have that nebulous
> >roundness we all love.
> >
> > This optic is a little long for a 35mm standard prime lens (100mm)
> >but the Medium-Format Bokehmaster is on the way as soon as I get a
> >working medium format focal-plane-shutter SLR. I have also considered
> >a Peter Gowland-style TLR but this will probably use two 40-series
> >Polaroid fronts on a rack.
>
>
> Bravo! ROTFL
>
> You might do an even more advanced model starting from a Polaroid
> Swinger, ca 1963. :-)
Laugh all you want, my negatives are not laughing. They have that
great Bernard's of Hollywood quality...well, OK, maybe not quite that
good, but for $25 worth of garage sale parts, what do you want? ;-)
Seriously, you don't want to piss with the plastic lenses in
Swingers, J33's or J66s. Even Instamatics have better lenses. The
optics I'm describing are just bad enough, not really worthless, such
as the Holgas and Dianas. If you have a Speed or Crown Graphic handy,
it's a half hour job to put one on a board and try it for yourself. I
think it beats the expensive soft focus optic from Mamiya for the RB
all to hell.
Also, these are uncoated optics, so in daylight, some sort of lens
shade would be beneficial.
In Middle Eastern fashion, after you shoot a wedding with this
contraption, should you hang up the old Polaroid bellows outside?
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