Date: Fri, 04 Feb 2000
From: jflanders2@home.com (Jerry Flanders)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: camera shake mirror induced - still happen on modern cameras?

Ingenious. This should allow you to estimate mirror slap

BUT - you don't really care about "raw" mirror slap. You care about the amount of _residual_ motion occuring while the shutter is open. If the motion has all subsided before the shutter opens, you essentially have all of the benefits of MLU without the bother. I suspect that modern camera manufacturers know all about mirror slap, and since the shutter firing timing delay and duration is so easily controlled by the camera's computer, it is likely that modern cameras delay the shutter opening long enough to avoid _any_ slap problem..

But - maybe not! Why not check it: It should be possible to use two laser pointers, combined with two phototransistors (Radio Shack - maybe $2 each) to see if the disturbance from the mirror has subsided before the shutter opens.

See my posting from last July on Dejanews,com - power search on "W4UK & shutter". Read about the basic circuit and my minor enhancement to it to allow you to measure shutter speed. This basic circuit would also allow you to see the effect of your lazer pointer's movement if you placed the phototransistor to intercept the beam, and adjust it so that you see the "shake" on the computer trace.

To correlate the shutter opening time with the above "slap" trace, duplicate the electronics from my posting and place this second phototransistor to intercept the shutter opening event. Hook this one to the other channel of the computer's sound card. Then comparing the CoolEdit96 traces for left and right channels should show you the exact instant the vibration subsides alongside the exact instant of the shutter opening.

Incidentally, consider tightly sticking a small piece of broken mirror onto the camera body, rather than strapping the lazer pointer to it. This might eliminate any resonance effect from the pointer's mounting.

Jerry Flanders W4UK

Date: Fri, 3 Mar 2000
From: Tom Trottier TomATrottier@home.com
To: Robert Monaghan rmonagha@post.cis.smu.edu
Subject: Re: Bad vibes

Hi Robert

Yeah, Carbon fibre is supposed to damp vibes more - good for bike frames too. Gel is also used in bike seats & gloves to absorb vibrations, maybe a gel tripod?

Olympus recommends holding the camera when you take a picture on a tripod.

Tom

Date: Fri, 3 Mar 2000
From: Robert Monaghan rmonagha@post.cis.smu.edu
To: Tom Trottier TomATrottier@home.com
Subject: lead dampeners? Re: Bad vibes

Thanks for your note ;-) I have been most interested in trying a thin disk of sheet lead; in our engineering classes, they highly recommend it for places like airplanes and machinery where vibration is a problem, saying it really kills and isolates vibration sources, only an ounce or so is probably needed, but I would want to see the tests on a scope first

second, I wonder if different tripods have bad resonant frequencies for particular shutter speeds and camera/motor drive combos? Might explain some of those odd reported test results I keep seeing? ;-)

regards bobm

From Rollei Mailing List:
Date: Tue, 21 Dec 1999
From: Mark Rabiner mrabiner@concentric.net
Subject: Re: [Rollei] Re: Rollei 35S and Oly XA; was: Rollei 35SClassic and Makrolon

"Joe B." wrote:

>Snip
> >THE WRONG DIRECTION. This is clearly blasphemy!
>
> The fact is that the Rollei 35 cameras were deliberately designed to be
> used upside down. >

I remember a Pop Photography where they illustrated using a camera upsidedown which rests the body against your forehead.

They claimed this was good technique to squeeze out another shutter speed!

No Bull!

Mark Rabiner

From Rollei Mailing List;
Date: Wed, 22 Dec 1999
From: "Joe B." joe-b@dircon.co.uk
Subject: Re: [Rollei] Re: Rollei 35S and Oly XA; was: Rollei 35SClassic and Makrolon

At 19:01 21/12/99 -0800, you wrote:

>I remember a Pop Photography where they illustrated using a camera upsidedown
>which rests the body against your forehead.
>They claimed this was good technique to squeeze out another shutter speed!
>No Bull!
>Mark Rabiner

Having no fear of experimentation, I actually tried this when I heard of it. I found it a bit tiring and I think probably any possible benefits are cancelled out by it being a bit if a strain to hold the camera this way. It also looks ridiculous!

My substitute method- this is talking about using a 35mm SLR as much as a Rollei 35 or anything else- is to turn my head more to the right than usual (I'm a left-eyed person) and press the back of the camera against my flat area of my left cheek; although this position doesn't feel natural it does feel really stable; due to the contours of my head this actually braces it better than my forehead could anyway.

Joe B.

[Ed. note: Tom has some interesting ideas for testing vibrations cheaply!..]
Date: Thu, 2 Mar 2000
From: Tom Trottier TomATrottier@home.com
To: Robert Monaghan rmonagha@post.cis.smu.edu
Subject: Bad vibes

Hi Robert

Good morning!

One idea I have for detecting vibration effects is to take a picture of a point light source, e.g. a laser pointer dot, that is travelling across the picture, e.g. by rotating the pointer on a turntable.

The monochomatic light should also minimise chromatic distortions.

With proper timing, you could even test the higher speeds.

Doing it diagonally would allow some measurement of both vertical & horizontal vibration components.

After all, it's the vibrations during exposure that matter.

OM source info:

< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@Zuiko.sls.bc.ca >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >

There is archive search available.

Tom

PS - have any info/links on film scanners? -Tom

[Ed. note: George shares some more of his interesting vibration related notes and projects... Thanks!]
Date: Tue, 4 Apr 2000
From: Blackcatzeke@aol.com
To: rmonagha@post.cis.smu.edu
Subject: info on vibration testing

Hi Bob ,

Thanks for giving me some ideas on going about doing the vibration tests.Bob you even answered a question which has puzzled me for quite some time and that is sympathetic tripod vibrations. I know many manufacturers that make plates for camera body to ballhead or pan head use a cork material. What really puzzzled me was that Brian Geyer ,of Really Right Stuff believes in metal plate to camera body contact to minimize vibrations. Your suggestion of lead is really worth pursuing.

As for the test I'll use one accelerometer mounted on the camera top housing and try these measurements with the camera mounted to a plate and ballhead and probably on a bean bag. I don't own any prime fl lenses except for the cz500f8Mirotar, the other lenses are big cz 28-85f3.3-4, and cz100-300f4.5/5.6 which has a tripod collar, for the nikon f3 i have a nikkor35-135. It will be an interesting experiment for me.The contax s2b has a really clunking sounding shutter so it should be interesting. On a non scientific test I balanced a nickel on the camera top housing and the s2b faired with the Nikon f3 but I don't think it will be as conclusive as my next project. When I get results I'll email you. Thanks again for providing me with your expertise and info from your great photo site.

Cheers, George Kmetz

Date: 08 Aug 1999
From: spoorl@aol.com (SpooRL)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: accelerometer tests... Re: Physics of mirror and shutter vibrations

I would also be interested to see how quickly vibration and shake diminish after an exposure is made with various brands and setups. I am well aware that if I cradle an F3 or F4 in my hands and fire the shutter, even with mirror locked, that a very noticeable vibration lingers for some time after mechanical action ceases. It varies with shutter speed, and it seems that exposures between 1/4 and 1/30 second (as many of us well know), create an amplified vibration after exposure. This is of interest to anyone who shoots quickly with a motor or makes multiple exposures of a composed subject. I don't use auto-bracketing, but have the idea that it might get caught badly in this cross-fire of vibration and produce less than optimum results. This kind of stuff matters increasingly as one uses longer lenses or does extreme macro work, where movement is literally magified.

It won't really be of value here to point out that larger format cameras with leaf shutters in the lenses, etc., minimize a lot of these problems, because the applications that I speak of, namely long telephoto and extreme macro work, are areas not well suited to larger format systems, both in terms of equipment and film expense, and in the range of lenses and gadgets to facilitate them.

Rick Spoo

Date: 08 Aug 1999
From: dwa652@aol.com (DWA652)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: accelerometer tests... Re: Physics of mirror and shutter vibrations

Well,

It is easy to perform such a test by mounting an accelerometer on top of various camera bodies and measure to accelerations. The tricky part is measuring the vibrations WHILE the shutter is open, but I suppose this could be done by using an optical (pulse) device to record the shutter opening and sync the data with the acquisition system. And you only need to record either the opening or closing of the shutter if the shutter is well calibrated I suppose. In fact, the signature of the accelerations might easily tell you when the shutter was open.

I use Columbia HEVP accelerometers (piezo-electric) at the office and could easily do the experiment if I had enough camera bodies! I do have an N90, F4s, Pentax 67, Fuji GX-680, etc. But the best experiment would be to test a large number of bodies all at once so that they are all tested right after the accelerometer calibration.

God Bless,

Don Allen
http://www.DonAllen.net

Date: Sun, 8 Aug 1999
To: rmonagha@post.smu.edu
Newsgroups: rec.photo.equipment.35mm
Subject: Re: accelerometer tests... Re: Physics of mirror and shutter vibrations

Hi Don et. al ;-)

I have a brief blurb on shutter speed testers, using FPT100 cheapy radio shack optical sensors, at

http://www.smu.edu/~rmonagha/mf/shutterspeed.html

and there is also a sound card shutter tester project posted at:

http://www.geocities.com/Yosemite/2131/shspeed.html

so the synch wouldn't be too difficult, I think. Possibly the shutter X-sych terminals could also be used, at least in some models, for a repeatable synch point? At the least, it would be most useful in the x-synch speeds running from 1/125 or 1/250th or so on most modern cameras down to 1 second or below.

There has been a good bit of controversy over slow speeds and mirror vibration esp. with long lenses. I would guess that a test would be done first with no lens attached or with just the standard 50mm lens? If available, a longer lens and long tele would be added to see what effect that dampening would have.

Another interesting series of quickie tests would be the effects of hand-holding, a sturdy tripod, not-so-sturdy tripod, bean bag, and bracing (against solid support like a tree or desk?) would have on camera vibration. I'd also be interested in seeing how a monopod impacts things...

In short, I think the whole vibration and camera shake testing topic is useful and likely to be full of surprises. I have seen some suggestions about avoiding certain speeds (like 1/30th and below) in books (The Lens Book, Roger Hicks and Frances Schultze) and magazines (outdoor photographer blurb on sharpness in '96, I think).

regards bobm

[Ed. note: another approach to "vibration" - its bad effects...]
Date: Wed, 12 Apr 2000
From: InfinityDT@aol.com
To: hasselblad@kelvin.net
Subject: Re: 201 F Body

Peter.Klosky@trw.com writes:

But how do you know if it has fallen? Impact damage may be all internal. Many users put their cameras on brackets, which may take the brunt of fall, on the surface. You never know how far and how hard a camera has been dropped by viewing its exterior.

Worse still is the effects of vibration. A lot of people ride around with their cameras in not-so-well-padded cases on the floor or trunk of their cars. Internal screws tend to work loose. Of course you can hear them rattle if they actually have fallen out but if they're just loose it's a ticking time-bomb. Many times the screws are "glued" in place from the factory but after a CLA they're not and so become more susceptible to vibration.

From Nikon Mailing List:
Date: Thu, 20 Apr 2000
From: "Glenn Garza" glenngarza@email.msn.com
Subject: Re: [NIKON] vibrations caused by motions other then mirror flip-up

Maybe 7 or 8 years ago, one of the photo magazines ran a test of most of the major brands current best for astro photography. At the time, the top Nikons were the F4 and 8008s (801x). They found that, even on cameras with MLU, a fairly significant source of blur (vibration) came from the shutters. They could tell this by the direction of blur for the stars. The cameras with the then newer vertical travel high speed shutters seemed to have much more shutter induced vibration than the others. I believe they noted (or maybe

I inferred) that the F3 was a better astro camera than the newer F4 and 8008s.

There was an apparent exception to this because they rated the Minolta, which had a high speed shutter, as the best of the new cameras. This was closely followed by an Olympus (I think).

They did say mechanical cameras were better suited because of not needing batteries for the longish exposures.

Glenn Garza

- ----- Original Message -----
From: Joshi, Mehul joshim@omrsystems.com
To: nikon@photo.cis.to
Sent: Thursday, April 20, 2000 5:12 PM
Subject: [NIKON] vibrations caused by motions other then mirror flip-up

> Hi,
> I have a basic question about vibration in the camera during taking
> pictures.
> Everyone talks about vibration caused by mirror flip-up and MLU issues...
> But I find that when I press the button (on F5 but it can be any camera), I
> hear noise, made by mechanical movements like aperture ring setting +
> shutter mechanism + shutter release switch toggle along with mirror flip up
[SNIP]
> Just curious ...
> -Mehul

From Contax Mailing List:
Date: Mon, 08 May 2000
From: "Bob Shell" bob@bobshell.com
Subject: Re: [CONTAX] Rx noisy shutter!!PLZ HELP

Mary certainly knows her stuff. The shutter on the RTS III is more than ten years old as a design, so it is certainly possible that the much newer shutter on the RX has a lot less vibration.

Bob

- ----------

>From: "Dan Lantz" dan953@earthlink.net
>Subject: Re: [CONTAX] Rx noisy shutter!!PLZ HELP
>Date: Sun, May 7, 2000, 9:19 PM  
> I believe it was Mary who answered, and she stated that,
> because of the improved shutter in the RX, that there is less total camera
> vibration during shutter release with the RX than there is with the RTS lll
> with the mirror locked up.  I know it sounds improbable, but that is what
> they say!!         

From Pentax Mailing List:
Date: Mon, 5 Jun 2000
To: pentax-discuss@discuss.pentax.com
From: Greg Erker erker@sask.trlabs.ca
Subject: Pentax Anti-Vibration Attachment patent.

Check out:

http://patent.womplex.ibm.com/cgi-bin/viewpat.cmd/US06069736__

A patent for an an antivibration attachment that goes between the camera and lens. The patent only appears to refer to CCTV applications but perhaps it could work be made to work with 35mm film.

The patent mentions that no increase in FL would be desirable but it limits the corrections you can do in the attachment due to thickness constraints.

(Speculation time) So perhaps the resulting device will be a low power teleconverter. Maybe even one that will turn the Limited lenses into normal FLs. If 43mm became 50 or 55 or 60mm then the TC ratio would be 1.16, 1.28 or 1.39. This would make the 77mm lens a 90mm, 98mm or 107mm.

Wouldn't that be funny if Pentax had this in mind all along when they picked the Limited lens FLs? (A 55mm and nominal 100mm A-V lens set.)

Warning: I'm not an optical expert and didn't read all of the 20 pages of the patent. So there may be reasons this will never be feasible for 35mm SLR lenses. But it's fun to speculate (IMO) and that is all I'm doing.

Greg E.

From Pentax Mailing List:
Date: Mon, 05 Jun 2000
From: michael simple@mail.portup.com
To: pentax-discuss@discuss.pentax.com
Subject: Re: Re Fluid dampened Tripods

Bob,

You're right about the question of rigidity, and the cork is a problem, as are typical quick release interfaces (not necessarily all, though) but the damping would be helpful to reduce "ringing". Since it is not possible to design a perfectly rigid mounting system that has no resonant frequency, the only options are to push it to a high enough frequency with low enough amplitued to reduce sharpness less than enough to be perceptible below the films sharpness "floor" (grain, basically) or to make the resonance low frequency enough that it won't affect shorter exposures much and damp it to low amplitude. For a carryable device, you probably won't be able to make anything rigid enough to create a high frequency/low amplitude ring (though removing the cork would certainly help this one), so damping can help significantly. This is why the claim is that wood is better, though most likely much less rigid than aluminum or carbon fiber.

Incidentally, in my Manfrotto Carbon One tripod, most of the flex and ringing comes not from the tubes themselves, but from the joints where the legs extend and where they attach to the head. So for rigidity, one piece carbon tubes that couple to the head with not pivot would probably be best, but it would be awful hard to fit in the car or carry through the woods.

Michael

Bob Blakely wrote:

> ----- Original Message -----
> From: "Cameron R. Hood" crhood@intouch.bc.ca
> Sent: Sunday, June 04, 2000 1:10 PM
>
> [skipped]
>
> > What I would like to see is Manfrotto come out with some kind of hydraulic
> > fluid  ballhead, with shock absorption built in, much like modern car
> motor
> > mounts.
>
> No, you don't.
>
> I know a lot of folks think shock absorption will help steady their cameras
> and reduce vibration, but it won't. In fact, whatever mass was moving to
> affect "shock absorption" in such a system would not be available to reduce
> the effect of vibration. It would be better to add an equivalent rigidly
> mounted mass.
>
> What is required is rigidity and mass.
>
> Period.
>
> Regards,
> Bob...
> (who stayed awake in physics class and became an engineer)

From Pentax Mailing List:
From: "Gerald Cermak" gfcermak@msn.com
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses
Date: Thu, 25 May 2000 03:07:49 -0700

The first 2 seem a bit blurry, but then again with golf-ball size grain it's really hard to tell the source. :)

The third one seems to have some nice crisper edges.

Another good test of vibration is to shoot a star in the night sky. Watch it dance and twirl on the print to give you an idea of tripod and camera motion. I've concluded I can't shoot constellations using my SMC Tak 500/4.5 on a Bogen 3236 even with Spotmatic MLU. The right exposure to use seems to be a few seconds, but the initial dance leaves trails that end at a bright spot for each star.

Cheers,
Gerald

From Pentax Mailing List:
From: "William Robb" wrobb@accesscomm.ca
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses
Date: Tue, 23 May 2000 20:33:08 -0500

A lot of blurring happens because of mechanical harmonics within the camera. This seems worst with Pentax anyway at 1/4 to 1/30 second, as I believe Valentin mentioned. Mirror lock is not the cure, as the shutter itself is the culprit. My lens flagging method, while workable, is not handy in many situations, and also will only work with the LX, not with any of the other cameras that share this problem ( the Super Program is probably the worst offender for this). The situation seems to be made worse by tipping the camera up for portrait orientation images. Obviously, this makes for a less than desirable situation, as often, we find ourselves using shutter speeds in the problem range with longer lenses. One option I have found that helps a lot is the use of a wood tripod. They really do dampen vibration to a great extent. Also, replace the cork pad on the tripod base with a neoprene pad. This prevents harmonics from being transmitted from the camera to the tripod and back. The logistics may prevent this, but hanging your gadget bag from the lens so that it weights and damps the mechanism can also help watch how much weight you hang on the thing, though). I find this better than carrying ankle weights and the like, as I would rather carry any extra weight in the form of film, or a lens, or a camera body or even a bottle of water. Which reminds me also, if you carry a canteen ( not a bad idea if you are going to be out and about), then it may provide enough weight for hanging onto the lens.

William Robb

...

From Pentax Mailing List:
Date: Tue, 23 May 2000
From: Shel Belinkoff belinkoff@earthlink.net
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses

William Robb wrote:

> One option I have found that helps a
> lot is the use of a wood tripod. They really do dampen vibration
> to a great extent.

I've heard this before, but for some reason dismissed it as not being a concern for 35mm work. So now it comes back to bite me on the ass.

I did a simple test just now, and tapped the Bogen t'pod head very lightly with my finger, and damned if I couldn't feel some vibration. I then did the same with a wooden broom handle, and the difference was substantial. Right after that I checked out the Reis web site and eBay. It looks like a new learning experience is upon me.

What do you recommend in the way of a good, inexpensive (are the terms mutually exclusive?) wooden tripod.

> Also, replace the cork pad on the tripod base
> with a neoprene pad. This prevents harmonics from being
> transmitted from the camera to the tripod and back.

That sounds like a plan. Good idea.

> logistics may prevent this, but hanging your gadget bag from the
> lens so that it weights and damps the mechanism can also help
> watch how much weight you hang on the thing, though).

Now that has me a bit concerned. I'd guess that anything hung off the lens should be done so as close to the camera body as possible so as to minimize the leverage effect of the weight pulling against the camera mount and body. Is this the idea?

-
Shel Belinkoff
mailto:belinkoff@earthlink.net

From Pentax Mailing List:
From: "Pavel Medek" Pavel.Medek@talema.cz
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses
Date: Wed, 24 May 2000

This is part of Realy Right Stuff printed catalog. RRS can be found at http://www.reallyrightstuff.com/.

"RRS camera plates intentionally avoid the use od any cork or rubber-type padding. Direct mating of the camera body and the mounting plate-without any intervening sponginess impoves the mass coupling between the tripod and camera. This assures best vibration damping, and enhaces rigidity."

Pavel

From Pentax Mailing List:
Date: Wed, 24 May 2000
From: Bruce Rubenstein b_rubenstein@yahoo.comB
Subject: Re: Sharpness, Slow Shutter Speeds,

A horizontal shutter, like the LX, should actually be better. The starting and stopping of the curtain drums creats a torque reaction around the axis of the drums, but this reaction is displaced from the mounting axis of the camera. The impulse generated is also probably of a lower amplitude, longer duration than the ones generated in a vertical shutter. The coupling between the camera/lens and the tripod is a low pass filter so there is better mass coupling for lower frequency vibrations. A tripod works by effectively increasing the mass of the camera and lens. For a given impulse this results in a lower displacement of the camera. The problem with tripods is that the energy transmitted into them is not immediately absorbed and travels up and down the legs (rings). A dampened coupling between the camera and tripod could eliminate this, but for it to work properly it would have to be tuned for a particular mass and frequency spectra. It's easier just to have the camera as rigidly attached to the tripod as possible. Two point couplings also work better. These are things like the Bogen long lens support, where the lens is mounted to the tripod and a strut connects the camera body to a leg of the tripod. Again, this makes the whole assembly more rigid, the more rigid the higher its resonant frequency and the higher the frequency the less chance of resonance of the whole structure. Wood provides better dampening than aluminum. An even better material is carbon fiber. Carbon fiber tripods can be very light, rigid and provide good dampening charateristics. They are not, however, $89.

Bruce R.

From: David A. Mann (pooky@caverock.net.nz)

That brings me onto another question. Has anyone tried testing a body with a vertical shutter against one with a horizontal shutter? I would expect a horizontal shutter to apply a torque around the least-supported axis of a tripod, causing more vibration as the vertical movement will be better supported and more damped due to less flexing.

From Pentax Mailing List:
From: "Bob Blakely" Bob@Blakely.com
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses
Date: Wed, 24 May 2000 06:33:58 -0700

For greatest rigidity about the vertical axis, tripod should have widest possible leg attachment, widest possible legs. Observe surveyors' tripods. Bogen 3046. There is a "triangle" formed by the two sides of the leg attachment and the leg's foot. The top of the triangle should be as wide as practical.

Regards,
Bob...

From Pentax Mailing List:
From: "William Robb" wrobb@accesscomm.ca
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses
Date: Wed, 24 May 2000 09:48:48 -0500

Hi Mafud, I will respond to both of your posts.

Mirror lock definitely reduces camera shake, by taking the vibration induced by mirror slap out of the equation ( I also read the Keppler article), and have found this to be true in practical applications. For myself, I use mirror lock whenever possible ( or better still, a camera with no mirror). However, the predicament Shel finds himself in, which I was answering to, is that even with mirror lock, a firm tripod, and a cable release ( IE: he has done everything "right"), he is still seeing mechanically induced vibration. The culprit in this instance has to be the shutter. I have also had exactly the same problem with my LX. Valentin did a test with his LX and determined that the shutter was in fact inducing vibration.

I was referring specifically to tripod mounted cameras with longish lenses. I actually intend to go out this weekend and see for myself exactly how much vibration I get from a freshly CLA'd LX and Super Program.

I invite you to disprove my assertions ( was I inflexible, or just sure of myself). A good check and balance would be for you to attempt to disprove, while I attempt to prove what I said. Then we can compare conclusions, and come up with specific circumstances where one must use caution against shutter induced vibration and where one can throw caution to the wind.

Cheers

Bill

From Pentax Mailing List:
From: "Mark F Dalal" mfdalal@inreach.com
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses
Date: Wed, 24 May 2000

From: Valentin Donisa vdpd@gemma.geo.uaic.ro

> I'd suggest to Shel (and this is not a joke) to consider mounting the
> camera to a big heavy plate, with two or three points of assembly. Have
> a lens collar with a first screw, and use a second one in the tripod
> mount, or two in the winder mounts. This way rotation around vertical
> axis, between plate/camera, would be severely reduced. Of course, he'll
> need a fine machinist to do him the plate and screws. Then, get a
> second plate mounted to this, with three adjustable/lockable big
> screws, that can also be mounted to a survey tripod, with several
> screws around. Now you can adjust the camera plate position, by messing
> with the three screws, and point it to your subject.

Hey Valentin,

This seems like an excellent suggestion. But, I'd like to reiterate that it would be much easier and probably less costly to purchase the Bogen 3420 telephoto lens support. This is designed for telephoto lenses without built-in tripod sockets. It seems as if it would be a great way to secure both the camera and the lens while mounting them on the tripod and balanced manner.

Mark

From Leica Mailing List:
Date: Wed, 24 May 2000
From: Jim Brick jimbrick@photoaccess.com
Subject: [Leica] Re: Benbo Tripods

The problem with tripods is that the vibration "moment arm" is the post that the tripod head/camera is mounted on. Most folks never raise the center post so that the head and platform is resting securely on the platform atop the legs. The only residual vibration you will get is from the legs themselves. And if you use a carbon fiber tripod, these vibrations are dampened out very quickly. Basically the best possible solution.

A Benbo tripod always has the camera sitting "out on a limb" so to speak. The "center post" is always extended, the camera is hanging out there, and vibrations are inherent. There is no way of dampening them. This will not cause a problem with an M camera, Hasselblad C camera (using MLU), or even a 4x5 with a leaf shutter. But it sure raises hell with SLR camera exposures, especially if they do not have MLU. This is one reason that Benbo tripods are not popular with the "pro" nature photo folks. Except for, of course, Heather Angel. But she uses a Hasselblad with C lenses and MLU 99% of the time.

Jim

...

From Pentax Mailing List:
Date: Thu, 25 May 2000
Reply-To: "Valentin Donisa" vdpd@gemma.geo.uaic.ro
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses

SudaMafud@aol.com wrote:

>Due to my time constraints Valentin, would you please search the archives for
>"mirror up" test[s] conducted by a list member about last June/July 1999?
>From Roberto Burgos (and my personal archives):

-----------------

OK, here are the results (better than I expected)

Gear: PZ1P, MZ5N (with and without battery grip Fg), FA200/f2.8, cable release Fg, laser pointer keychain, Slik 444 tripod with standard head, clothespin, two rubberbands, ruler.

Setup: Tripod fully extended, center post down, camera(s) attached to tripod head (no tripod base on the FA200), laser pointer strapped to lens hood (with rubberbands) pointing to where the camera is aiming (lens axis), clothespin holding gthe laser pointer on button pressed. Gear was indoors (no wind), projection beam at white wall exactly 17 meters away.

Tests set A:

All test shots were done at 1 full second shutter speed with cable release.

a) Single shot without MLU (2 sec), horizontal & vertical

b) Single shot with MLU (PZ1P only), horizontal & vertical

Results A:

PZ1P / horizontal / no MLU: oscillation was less than the laser beam's diameter, which I calculate in about 10 millimeters.

PZ1P / vertical / no MLU: oscillation was about 15 millimeters, in an up and down motion

PZ1P / horizontal / 2sec MLU. Less oscillation than with horizontal. Still not measurable.

PZ1P / vertical / 2sec MLU. Not measurable but still noticeable.

MZ5n (with grip Fg) /horizontal/: About 10 mm oscillation, up/down motion

MZ5n (with grp Fg) / vertical/: About 15 mm oscillation, circular motion.

MZ5n (no grip Fg)/ horizontal: Not measurable

MZ5n (no grip Fg) / vertical: About 10 mm oscillation, circular motion.

Other discoveries:

a) In both cameras, when the mirror flaps down (end of exposure), there is a big shake. It doesn't matter because the picture is already exposed.

b) Motion happens during the first moments of the exposure and soon stops.

c) I tested both cameras on continous shots/film advance. There is a strong oscillation probably due to winder torque. On both cameras the movement is circular and bigger that 30 mm oscillation.

d) Hanging my camera bag (about 20 pounds wt.) to the tripod seems to reduce all oscillations to none detectable.

e) Tests done tripping the shutter by hand. Oscillation was too big.

Conclusions: As reported be Herbert Keppler (Pop Photo sept 99?), MLU does work but is more noticeable at medium long speeds (1/30 to 1/2 sec.) Longer speeds do have the same degree of movement but since the exposure is taken during a longer period of time, the image is recorder mostly at no oscillation moments.

Hanging something heavy from the tripod does help.

Vertical shots are more prone to oscillation.

Use a cable release.

**************************
OK, where is the math wiz?

Roberto Burgos S.

From Pentax Mailing List:
Date: Thu, 25 May 2000
From: Shel Belinkoff belinkoff@earthlink.net
Subject: Making a Bean Bag to Reduce Vibration

In light of the recent discussion about sharpness and the use of tele lenses, tripods, and slow shutter speeds, I'm embarking on a step-by-step process that will, hopefully, result in sharper images when shooting in such situations. One item I'd like to make is a bean bag to drape over the camera when it's mounted on a tripod. Although I have some ideas for this project, I'd like to get others. So, if you've got some thoughts on the matter, let's hear 'em. Ideas about what to fill the bag with (beans, rice, lead pellets), the size and shape of the bag (I was thinking rather long in relation to its width so it could easily drape over the camera), material from which to make the bag (I've some burlap handy), and so forth. Thanks!

From Pentax Mailing List:
From: "Bob Walkden" bobwalkden@hotmail.com
Subject: Re: Making a Bean Bag to Reduce Vibration
Date: Thu, 25 May 2000 20:37:44 BST

Hi,

Make it with a velcro-fastened opening at one end so you empty and refill it at will. No point filling suticases with heavy, bulky "beans" when you go on a trip.

Make it water-resistant.

For the weight on top of the camera you might consider using marbles (do you have them over there - they are glass sphere that young boys play games with. Also called 'alleys' I think). They're easily obtained over here and probably a lot cheaper than the equivalent number of ball bearings or weight of lead shot. Sand would also be good - especially wet sand (in a plastic bag inside the beanbag).

Make it with a loop so you can hang it from the tripod and fasten it to other things.

Beans and rice etc. are better for underneath the camera.

Hope that helps,

Bob

From: corber aylin.coray@wxs.nl
Date: Tue, 13 Jun 2000
Newsgroups: sci.astro.amateur
Subject: Re: Vibration pads??

Hi All,

Im using a set of rubbers (1.5cm thick, 6cm diameter) normally used to stop dishwashers from shaking. For hardly any money they reduced vibration on my CG-5 (6" Intes micro MCT) drastically.

Clear skies

Cor

Ritthem, The Netherlands

[Ed. note: telescope users put small vibration pads under scope tripod to cut vibration...]

From: "John Sylvestre" jsylvestre@videotron.ca
Newsgroups: sci.astro.amateur
Date: Mon, 12 Jun 2000
Subject: Re: Vibration pads??

They do what they advertise. However a poor man's version does almost (I am perfectly satisfied) the same job and cost A LOT less:

Material required:

1 - Mouse pad (the thick ones)

2 - A set of wood/felt protectors you place under furniture legs to protect wood floors (I forget the actual term - I'll call it a furniture coaster). There are different sizes; one can find a set that fits the tripod you are using.

3 - A little glue

Cut the mouse pad into pieces that fit into the (not the felt side) coaster and glue.

One instruction and you have a poor man's set of vibration pads. Best of all it works.

Clear Skies

From: hermperez@worldnet.att.net (Herm)
Newsgroups: sci.astro.amateur
Date: Wed, 14 Jun 2000
Subject: Re: Vibration pads??

I own two different sets of pads..the Celestron and pads made for industrial equipment vibration dampening..both work equally well in damping time (excellent results)..the industrial pads are better on heavy equipment such as a 10" LX200 or G11 with sct. Note that if you need to remove the rubber tips on the LX200 if you use the pads, otherwise you will worsen the problem. Here is the source of the industrial vibration dampening pads (mostly used in refrigeration equipment):

http://www.vibrasystems.com/prod_07.htm

These sometimes can be found in refrigeration supply stores ($4 per pad), but be careful they don't give you the wrong one. They make different ones for different loads..the pads must be made of compressed cork lined on both sides with neoprene.

Herm

From: "Gerald Cermak" gfcermak@msn.com
To: pentax-discuss@discuss.pentax.com
Subject: Re: Sharpness, Slow Shutter Speeds, & Tele Lenses
Date: Thu, 25 May 2000 03:07:49 -0700

The first 2 seem a bit blurry, but then again with golf-ball size grain it's really hard to tell the source. :)

The third one seems to have some nice crisper edges.

Another good test of vibration is to shoot a star in the night sky. Watch it dance and twirl on the print to give you an idea of tripod and camera motion. I've concluded I can't shoot constellations using my SMC Tak 500/4.5 on a Bogen 3236 even with Spotmatic MLU. The right exposure to use seems to be a few seconds, but the initial dance leaves trails that end at a bright spot for each star.

Cheers,
Gerald

From Pentax Mailing List:
Date: Mon, 24 Jul 2000
From: Mike Johnston michaeljohnston@ameritech.net
Subject: Re: Shutter-shock

Believe it of not I have read (in Carl Zeiss literature which I can't locate at the moment) that the RX mirror/shutter vibrations are lower than the RTSIII with its mirror locked up, so there is part of the answer.

This is true. Generally, the higher the top speed of the shutter, the greater the shock and vibration (and, not coincidentally, noise) contributed by the shutter mechanism itself. Over the years, engineers have largely solved the problem of mirror shock, but, as this has happened, shutter vibration has begun to contribute more and more to total vibration during shutter release.

This is why a lot of manufacturers no longer provide mirror lock-up (MLU)...because the mirror shock isn't terribly significant compared to shutter vibration. The lowest-vibration shutters, typically, are the 1/1000th rubberized-cloth shutters found on cameras such as the Pentax MX and Leica M6.

--Mike

Date: Thu, 31 Aug 2000
From: "jjs" john@stafford.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Mirror Vibrations in Medium Format

Scott Daniel Ullman sdullman@i_hate_spam.stanford.ude wrote

> I've been toying with the idea of getting into medium format, although I
> haven't decided between 6 x 4.5 and 6 x 7.  I've been looking at the Pentax
> 67II, Pentax 645n, and Mamiya 645E, and from reading discussions and reviews
> of various medium format cameras, the issue of mirror vibrations seems to
> keep coming up.  [...]

It is important to consider the specific application. Very long lens work, or Macro (or micro) work can show you where vibration is a serious problem, but it can usually be overcome. Otherwise, for most work the notorious Pentax 67's so-called shutter shake can be obviated by shooting at 1/4 second or longer, or 1/250 or faster (depending upon the lens.) To be fair, I think any focal plane shutter camera has a certain liability regarding shake at certain low speeds.

(I just finally got a picture I've been working on for too long which involved a 600mm lens on a 35mm camera and camera shake was a significant problem. Finally, the pictures which showed the least camera vibration were the long exposures (1/4 to 1 second.) And this is a manual 35mm with a mirror lock up and a smooth vertical shutter. If someone wants to donate a 1200mm MF lens, I will make this thread pertinent. :))

Does the Pentax shake? See http://wind.winona.msus.edu/~stafford/s/p1.html
(but NOT if you have a slow PC or connection!)

Date: Mon, 21 Aug 2000
From: "Q.G. de Bakker" qnu@worldonline.nl
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Is MF worth the effort?

George Hager wrote:

> Maybe Brian, we  have a different conceipt of sharpness.
> Maybe my camera and the one the physics prof. tested were
> unique.  Maybe we were just unlucky.
> At any rate, it is not a major problem as it only happened
> at the nasty shutter speeds (from 1/30 down to 1/2) and it
> didn't always show there.  I am not trying to instill doubt
> in the usage of the Pentax 6x7 (as I stated, I thought it
> was a very good camera).  I am only trying to make others
> aware of a problem that existed in my camera.  I did not
> experience the problem in my 35 mm, my Hasselblad or my
> 4x5.

It will happen with (almost) all cameras. Hasselblad too (to name but one) has issued a warning against this. It occures in tripod mounted 500 C(...) cameras at shutterspeeds of 1/15 and 1/30 sec. And it is sure to happen in the other models at the same or other speeds as well. The solution to minimize or even prevent this is to make all non-moving parts really massive, while reducing mass of all moving parts. But how about a camera that weighs a ton and has a flimsy mirror? Or they could make the mirror move real slow. That too would perhaps not be popular. ;-) The only thing we can do is have a thought about how we support our cameras.

Hasselblad (and others) suggests to 'hand hold' the tripod mounted camera when doing these speeds.

And of course we could use mirror pre-release...

> I check for sharpness with a Maxwell 9.5x loupe.
> Perhaps we shoot different things in a different style and
> this accounts for your success (the Arca Swiss head would
> definitely help - I used some kind of Bogen abortion for a
> head that wabbled if a mosquito burped in the forest).

The Arca Swiss head has an adjustable friction lock, i.e. the head is not locked as rigidly as possible, but held just tight enough not to move on its own. This will allow the head to absorb some of the vibrations caused by the camera. Perhaps just enough to get that extra bit of sharpness?

Date: Sun, 03 Sep 2000
From: Roger roger.cantwell@virgin.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Mirror Vibrations in Medium Format

Scott Daniel Ullman wrote:

> Thanks.  From what I understand, there is no one type of medium-format camera
> that is good for everything.  If the intended application is hand-held
> shooting at speeds of at least 1/60, using at most a portrait telephoto
> lens[1], would the mirror vibrations have an effect?

If you're using flash (e.g. in a studio), it's no problem! In continuous light, I'd stick to 1/125 or faster for a portrait lens, even with no vibration. Some people believe that mirror vibration is less of a problem when handholding, because your fleshy hands absorb the movement - a tripod could vibrate in sympathy, especially if lightweight or over-extended.

--
Roger

From Leica Mailing List:
Date: Wed, 15 Nov 2000
From: Jim Brick jim_brick@agilent.com
Subject: [Leica] Re: RE: Ball- or 3 way-head

Dan Post wrote:

>KOWA-BUNGA!
>I wonder, and I wonder- Why would anyone want to use a light weight tripod?
>I thought the whole idea of the tripod was to create a heavy, stable, not to
>shake rattle roll or quiver in the wind platform so that the image would be
>as sharp as possible?
>I miss my big ole clunky Star-D, looks like a Tiltall, heavier than dirt
>tripod for that reason!
>
>Dan ( I want something sturdy, heavy and dependable for as long as the wind
>blows, the water flows, the grass grows, and the sky is blue....) Post
>

Turns out that both wood and carbon fiber are better than the venerable heavy steel, step on a crack break your mothers back, tripod. They are dampening to camera vibrations. Carbon fiber winning over wood. When that ol' mirror slaps up there and the first curtain opens, the composite legs absorb the vibrations rather than resonating and echoing them right back into the camera before the shutter has time to close. 1/15, 1/12, 1/8, 1/6, 1/4, 1/3, 1/2, 1/1 are the vulnerable deadly speeds. Especially with things like Pentax 6x7 and the like. A fiery horse with a speed of light, A cloud of dust, and a hearty "Hi-Yo, Silver," in rides the Carbon Fiber tripod.

The TV/movie-documentary chaps and chappetts discovered this a few years ago and have extolled their virtues ever since. Us still folks are slow to catch the wave.

Jim

[Ed.note: Mr. Covington is a noted author of astrophotography books and articles...]
sci.astro.amateur
From: "Michael A. Covington" for.address.look@www.covingtoninnovations.com
[1] Re: Caster Vibration Dampers
Date: Sat Jan 06 22:36:06 CST 2001

Adding wood to the structure of a mount -- almost anywhere -- is another good way to damp out vibration. The lighter the wood, the better: basswood, balsa...

sci.astro.amateur
From: Bob Berta rkberta@hotmail.com
[1] Re: Caster Vibration Dampers
Date: Sun Jan 07 00:23:34 CST 2001

Vibration amplitude is greatly reinforced by a hard connection the ground....like hard metal tripod tips on the ground. The Celestron Vibration reducing Pads are particularly efficient at vibration reduction. They use an inner and outer layer of very hard plastic sandwhiching a inner layer of a sorbothane like material. I have done some experiments and found that you could do quite well with just a piece of 1/4" rubber under each leg also...not quite as good as the VRP but pretty good. A layer of the same 1/4" sheet rubber placed between my wedge and scope base on my SCT also made a bit of improvement. Last trick I did was fill the lower legs of my Celestron Heavy Duty tripod with sand. The combo of the rubber sheet on the wedge, sand and the VRP makes my scope rock solid...it is almost impossible to get any sort of vibration...any tap is damped out instantaneously. Works great for CCD imaging..gives nice small round stars.

The worst thing you can do is place hard metal tripod tips against the hard ground like pavement...that will really emphasize vibration.

Bob Berta

sci.astro.amateur
From: aberrator corber@my-deja.com
[1] Re: Caster Vibration Dampers
Date: Sun Jan 07 2001

Im having the same tripod and use a set of rubber dampers normally used for washing-machines.

my 2 cts,

Cor Berrevoets
Ritthem, The Netherlands
Aberrator free star-testing software
http://aberrator.astronomy.net

sci.astro.amateur
From: "Brian Murphy" bmurf@tcon.net
[1] Re: Caster Vibration Dampers
Date: Mon Jan 08 13:08:59 CST 2001

I use heavy-duty boot heels from the shoe repair shop. Cost $2 each and work great.

Brian

> >I have my EQ mount (Starfinder  pier)on a homemade wooden "Wheeley Bar" with
> >3" Rubber wheels and 2X4's. With home made vibration suppression pads, I
> >have got the vibration times down to just under<1 sec. Considering the load
> >I am putting on my mount, it's not bad (using the tried and true
> >"firm-rap-on-the-tube-test" ;)
>
> Are you going to tell us how you made your "... home made vibration suppression
> pads ..."?  8^)

sci.astro.amateur
From: "Orion" mark.bender@cdc.com
[1] Re: Caster Vibration Dampers
Date: Mon Jan 08 18:13:58 CST 2001

re: "How I made the home made vibration suppression pads"

It was actually pretty simple. I bought those crummy plastic coasters at the dollar store, with the cork linings. Took the cork out, glued them to a sheet of ~ 1/4" rubber, made a sandwich of rubber, cork, rubber, glued them back into the coasters,

And, voila', Celestron vibration supression pads for a couple of bucks...

CDS

Orion

sci.astro.amateur
From: jerry_pool@my-deja.com
[1] Re: Caster Vibration Dampers
Date: Mon Jan 08 09:40:02 CST 2001

...

I have a standard C8 and had severe damping problems. I built a home made wheelybar with casters but installed 1/2" rod as levelers. To supress vibration I cut 3" squares from old running shoe soles, placed a 5/16" rod with a turnbuckle for tensioning and the result was dramatic. Damping time was reduced from 6-8 seconds down to 1-2 seconds. You can see the setup here. I also made my own adjustable wedge.

http://hometown.aol.com/nlpjp2/index2.html

Regards, Jerry

[Ed.note: thanks to David Grabowski for sharing these testing tips etc.]
Date: Sat, 30 Dec 2000
From: nimages@capecod.net (David Grabowski)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Pentax 6x7 Mirror/Shutter Shake Test1 completed

david_of_oki@my-deja.com wrote: >I've been reading many posts on here and reviews >on photographyreview.com complaining about >mirror/shutter vibrations in the Pentax 6x7. It >all kind of scared me, but I decided to buy the >camera anyway. I got a near-mint older version >with mirror lock-up, TTL prism, and 105/2.4 >lens. I just recieved it yesterday and the first >thing I wanted to do is test this "mirror" shake >syndrome. I grabbed a new roll of TMax 400, got >a fresh battery, and did this: > >- Hand held, without locking mirror, from 3.5 >feet away. Focused on a set of tassles hanging >from a flag, indoors, pretty low light. Set the >camera's ISO at 1600. > >- 1/15 sec @f/11 >- 1/30 sec @f/8 >- 1/60 sec @f/5.6 >- 1/125 sec @f/4 >- 1/250 sec @f/2.4 > >- Developed in TMax Developer and scanned into >Photoshop 5.5 with Kodak Professional RFS 3570 >Film Scanner (a no bullsh*t scanner). > >Results---- I could see on the negatives that >the 1/15 second exposure had camera movement. >Once scanned in and compared, the 1/30 sec looked >as sharp as the 1/250 sec exposure. Of course >the others did too. The 1/15 sec was the only >exposure that looked affected by the >mirror/shutter vibrations. > >Conclusion---- First of all, there is a Test2 in >progress. It will be to test the vibrations for >an object far away. But about this test1, what >can I say? My guess is that the people who >complain either have trouble staying still while >shooting, or their cameras have some kind of >defect. I've read complaints about vibrations >affecting photos in exposures up to 1/125 sec. >NO WAY! > >I hope not to eat my words in Test2. > >If anyone would like me to send him/her a >pictoral display of Test1, email me at >rothd@mcbbutler.usmc.mil > >The display on file is 9"x11" @ 400 dpi. I doubt >anyone would want to recieve an attatchment that >big, so tell me the largest file size (in kb or >mb) you want me to mail, and I'll do it. > > >Piece, >David

Mirror shake problems , especially with 6x7 slr cameras is not limited to the Pentax. Also try your tests over again on a tripod, handheld is actually superior in many cases to tripod mounted shots that are exposed under 125th second without mirror up . I know for sure my RB 67 Pro S suffers from this without mirror lock up , enough so that it's useless to shoot from 1/60 down on at least my tripod without locking up the mirror and at 1/8 sec. the images are not even salvagable if not using mirror up. I can hand hold acceptably at 60th sec. though and can only assume hand holding offers more dampening than tripod mounted will.

By the same token I can handhold fairly well down to 1/30 with a TLR in 6x6, in many ways I like TLRs over SLR, one being that you can use a much lighter tripod for slow shutter work. The big downfall is not viewing through the taking lens but these are still very viable tools IMO .

Since you now have a Pentax 67 and probably will tripod mount it at some point in time, be forwarned about springy camera shake on a tripod. And my suggestion would be to get used to a cable release , as well as the mirror up function. But don't take my word for this at all, just run your own tests, it will be obvious enough soon enough.

David Grabowski

From: tjacmc@aol.com (Tjacmc)
Newsgroups: rec.photo.equipment.35mm
Date: 26 Jan 2001
Subject: How to measure and control camera vibration.

You can find an easy way to see, measure and control camera vibration at the bottom of the website below:

http://members.aol.com/Tjacmc/index.html

http://hometown.aol.com/Tjacmc/index.html

[Ed. note: while the classic Bronica S2 series cameras have the loudest shutter in medium format camera's I've ever heard, most of the noise and vibration is after the exposure, as Sam Sherman's clever test shows...]
From Bronica Mailing List:
Date: Wed, 07 Feb 2001
From: flexaret@sprynet.com
Subject: Re: Vibration

Jack,

There is little to no actual vibration on a Bronica S2A, S2, C to affect picture sharpness.

Most of the vibration comes AFTER the picture is taken and the mirror returns to rest.

Further, the dropping mirror does not cross the picture axis as in a standard raising mirror which causes blurr - but moves down and forward towards the lens.

Test this by holding your camera with magazine off in your hands and release the shutter at B holding the shutter open and without the mirror returning. You will feel very little vibration as compared to other medium format SLRs.

I can hand hold my Bronica S2A for sharp photos down to 1/30th second. You don't need mirror lockup or sandbags.

Of course if you can use a tripod at any time it is always the best, you don't need sandbags.

However, I have been using my Bronica S2 for an out and about series of photos I have been taking in New York City. All of these hand held and with 75MM and 200MM lenses - all photos are perfectly and exceptionally sharp.

However, I advise using speeds of 1/125th, 1/250th and 1/500th whenever possible.

- Sam Sherman

>From: Jack Kirkhuff targahh@mcn.net
>To: Bronica@yahoogroups.com
>Subject: [Bronica] Vibration
>Date: Wed, Feb 7, 2001, 10:38 AM
>

>I use an ancient wooden tripod with a newer head attached for my S2A.
>On slow shutter speeds (under 60) I usually apply slight downward
>pressure to the camera as I release the shutter. Have had no problems
>with blur.
>
>Jack Kirkhuff

From Bronica Mailing List;
Date: Mon, 14 May 2001
From: "LAWRENCE REISS" paraxial@hotmail.com
Subject: Re unsharp with extensions

Jonathan,

I have the Sqa and encountered high levels of vibration with this camera as well. Upon dissassembly, I found that in this model there is a rather heavy spring that is used both for the mirror mechanism and also to trip the shutters in the lenses. I substantially reduced the tension in this spring, and also lubricated the mechanism track. This resulted in considerably less energy being turned into unwanted vibration during exposure. Undoubtedly this has slightly increased the time lag between shutter button and exposure when the mirror is flipping, but I do not percieve the change. The spring is originally stiff to allow for the necessary energy to trip the shutters in the bronica lenses, and as these age the lubricants in them become stiff - and require more force. For good measure I also relubed these as well using synthetic lubes (which last longer).

Of course, the long length of your combo makes for a vibration prone system.

Support directly under your lens would be helpful, as well as an increase in weight directly under the camera / lens combo - eg a heavy metal plate to which the body/ lens combo attaches.

Hope this is of some use despite the long interval in replying. Feel free to write to me directly at Lawrencereiss@yahoo.com if you have further questions.

By the way, I also use a bit of foam between the mirror bottom plate and the noisy door that swings up and clangs against it...

Lawrence

>Since the list seems to have lumbered to life, I thought I'd throw out a
>question and see if anyone has solved this problem.  .  .
>
>I recently picked up an SQ-Ai and have noticed that I'm not getting sharp
>images with the 36mm extension tube, especially when used with the 150  PS.
>Mirror is locked, cable release in use.  Then during some tests, I left  my
>hand on the lens while taking 2 second exposures and noticed that there  is
>a noticeable vibration when the shutter is released, but none when the
>shutter closes.  This must be due to the lens stopping down before  shutter
>release, and since the aperture is so far away from the tripod mount when
>using the 150 + 36mm extension, vibration becomes significant.  Has  anyone
>dealt with this problem and resolved it satisfactorily?
>
>Thanks,
>
>Jonathan Prescott

From: tjacmc@aol.com (Tjacmc)
Newsgroups: rec.photo.equipment.35mm
Date: 31 May 2001
Subject: Seeing, measuring and controlling camera vibration

You can find some useful information on seeing, measuring and controlling camera vibration at the BOTTOM of the website below:

http://members.aol.com/Tjacmc/index.html
http://hometown.aol.com/Tjacmc/index.html
http://members.aol.com/floatinghabitats/index.html
http://hometown.aol.com/floatinghabitats/index.html

Date: Tue, 10 Jul 2001
From: Balazs Ujfalussy ujfalussyb@ornl.gov
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Minolta Mirror Vibration

A Recent thread over at MML mentioned a measurement of Mirror lock up effects in the Maxxum 7. The method they used is at

http://members.aol.com/_ht_a/Tjacmc/vibrate2/vibrate.html

The result was, that the mirror flap caused 0.0034mm blur on film.

Hope this helps,

Balazs
(blu@icx.net)

From Nikon Mailing List:
Date: Mon, 02 Jul 2001
From: Henry Posner/B&H; Photo-Video henryp@bhphotovideo.com
Subject: [NIKON] Re: Tripod collar on new AF-S 300 f/4

you wrote:

>To get sharp results with a 300mm you have to cradle the
>lenses with your hand as near the front of the long lens as posible and
>press the rear of the camera body firmly against your face.

Try holding the lens in the left hand, palm up, with the hand at the center of the lens by weight. Brace the left elbow against the ribcage and use the right hand to release the shutter. All the weight of the balanced lens is distributed from the arm through the torso to the legs. Holding the lens at the very front means the other (presumably right) hand has to support part of the weight while releasing the the shutter, which is a sure-fire way to impart the downward motion of the trigger finger to the camera.

- --
regards,
Henry Posner
Director of Sales and Training
B&H Photo-Video, and Pro-Audio Inc.
http://www.bhphotovideo.com

Date: Sun, 08 Jul 2001
From: "Nicholas O. Lindan" nolindan@ix.netcom.com
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Mass Coupling Questions

Joe Lacy wrote:

> Which head and leg set combination achivies the "BEST" results?

Gee - lets figure out the "BEST" camera, film, lens etc. first - it's an easier topic.

The general sage advice is everyone has to make up their own solution for their set of problems and resources.

General sage advice, though is:

With LF there isn't much camera generated shake so the high frequency damping of the camera/head/tripod/surface combination isn't an issue. A good test of high(er) frequency vibrations to mount everything up and give it a tap, resting your finger lightly on the camera. If you feel a nice bell tone that takes eons to die out you have the _wrong_ combination: Some Gitzo/Blad combinations do this.

Note, though, that stiff and 'ringy' combination will be very stiff and will not shift in high winds, though you do now have to be careful of the wind whistling through the apparatus.

A good test of a tripod is to thwack the legs - if there is a dull thud response, like you tapped a lead pipe, the legs are OK.

Next is the center column. Columns that are not braced to the legs are hell for resonance. Consider getting a sawed off column. You can also damp the column with a heavy weight (lead is recommended) placed about 1/7th from the end - before fixing the weight, though, test with your camera. Wrap the weight tightly in an old bicycle inner tube and insert (should be an awfully tight fit - technical term for this used to be WNF: "Wedding Night Fit", though I guess that means a real sloppy fit these days) using RTV as a lubricant/adhesive. This is not the solution for backpacking, though - you are carrying around several pounds of lead.

A portable solution is plastic grocery bag filled with stones hung from the center column.

A standard stiffening trick is to spread the legs and then lasso them together, about half way up, so the legs have a bit of a curve to them. The legs won't move now unless enough force is applied to loosen the string. Chain works best for this application, and many surveyors tripods are so equipped.

The general consensus for large format gear is that Reiss legs and heads seem to work the best. For a great tripod at moderate cost get an old surveyors 'pod'.

--
Nicholas O. Lindan, Cleveland, Ohio nolindan@ix.netcom.com

Date: Sat, 26 May 2001
From: "ozymandias" ozymandias@hamangia.freeserve.co.uk
Newsgroups: uk.rec.photo.adverts
Subject: Unshake 1.2: Clean blurred photos. Free software.

Unshake is free software, which improves blurred photos by working out the average blurr and compensating for it, to estimate what the original scene looked like.

Unshake handles camera shake, poor focus, haze/fogged lens, and incidentally helps hide rasters and can rebalance colour. It's free beacuse it's the program I wanted, but couldn't find, so now I've written it I want others to have it. (You never know, someone might want to pay me for it.)

Unshake 1.2 is better than Unshake 1.1 because:

1) It gives better pictures.

2) It is easier and more convenient to use.

3) It usually gives an improvement first time, without adjusting the controls.

4) It has a "batch" option, which allows you to process up to 50 pictures in succession, automatically.

5) It is a bit faster.

Unshake can be tried out online with two examples of my bad photography, before installing on your computer.

To try the trial version out for personal use only, go to

http://www.hamangia.freeserve.co.uk/Unshake

Have fun.

From: ladagency@aol.com (Ladagency)
Newsgroups: rec.photo.equipment.medium-format
Date: 20 Aug 2001 
Subject: Re: med fmt lens tests URL Re: Mamiya TLR Lens Question

Speaking of camera shake, I am reminded of the two basic stances in shooting a
firearm: the Weaver and Isoceles stances.

The Isoceles is when you hold both arms out locked at the elbows. Of course,
the main movement is on the vertical axis. I call a good target pattern the
'zipper'.

The same goes for cameras. If you hold the camera from the sides and against
your eye socket, there is a potential of side-to-side movement.

Combine your grips and body contact to form as much of a tripod as possible,
and camera shake will be less and better distributed. 

From: "Leonard Evens" <len@math.northwestern.edu>
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Mamiya TLR Lens Question
Date: Sat, 18 Aug 2001

"Roland"
<roland.rashleigh-berry@virgin.net> wrote:


> Keith Wiebe wrote:
>>
>> > As to the subject of using a tripod, in my mind there is no sense
>> > shooting large film if you're going to jiggle the camera. I don't
>> > hand-hold
>> anything
>> > larger than 35mm. If the shot's worth taking with MF, it's worth
>> > using the tripod and a cable release.
>> You know that the bigger the film the less shake affects the sharpness?
>> Most people believe that 35mm can be handheld but it is exactly the
>> type of camera that needs to be tripod mounted because of the small
>> film size and consequent more degree of enlargement. Picture this: If
>> you had a film the size of 16x20 you could handhold it at a lot slower
>> speed because of the small shake one produces isn't enlarged very much.
>> Anyway, I do generally agree that if one takes photography serious and 
>> uses medium format, one should try and take pictures with a tripod.
>> Keith Wiebe
> I get much more shake from medium format when I hand-hold. Quite the
> opposite of what you say. When I get a new medium format folder camera I
> always do a test roll and the first few shots will be with my NOT
> supporting the lens at the front of the camera in any way just to give
> an indication of the inherent shake. For some of these folders the shake
> is extreme, like the Perkeo II. To take sharp hand-hel;d shots with that
> (or even tripod mounted for that matter) you need to employ a Vulcan
> Death-grip on the lens to keep it still. I have never noticed
> hand-shake on any of my 35mm cameras no matter how clumsy I have been or
> how much I enlarge.

I think a lot depends on the kind of camera. For cameras held at
eye level with large heavy lenses, what you say may be true. It is
probably harder to brace a medium format camera against your cheek and
for the same angle of view, the lens will be longer and heavier than for 35mm. On the other hand, I was able to take pictures with a twin
lens reflex hanging from my neck regularly at 1/60 and sometimes at 1/30
without a lot of movement.

--

Leonard Evens len@math.northwestern.edu 

From Nikon MF Mailing List:
Date: Tue, 21 Aug 2001 
From: "Roland Vink" <roland.vink@aut.ac.nz>
Subject: Re: Macro camera shake/shutter speeds

> It has been mentioned recently in the thread on MLU that macro work
> is more prone to shake. Does this mean that the normal "rule" of hand
> holding a lens (that you should set the shutter speed to a maximum of
> the reciprocal of the lens length) does not apply at high
> magnification? Is there another rule which takes into account the
> magnification and lens length?

Hi Ben,
The hand-holding rule is a good guide when using lenses at normal
distances, where the magnification on the film is very small.

Note that it is only a guide, and you should adapt it to your style. Like
DOF and the circle of confusion, there are varying views on what is
acceptable camera shake. It depends on the final image size, viewing
distance and the purpose of the image. Some photographers happily
 shoot at 1/15 sec with their 50mm lens and insist they still get sharp
pictures. Others double the hand-holding rule and won't go lower than
1/100 sec with a 50mm lens. Bryan Geyer of Really Right Stuff would
have us believe that hand holding is strictly for dead photographers (no
pulse to induce movement) so you should use a tripod (with matching
RRS plates of course) for every shot.

The logic behind the hand holding rule is simple: as magnification
increases, camera shake is also is magnified. Shutter speeds need to
increase to keep camera shake blur to an acceptable level.

A normal distances, the focal length is a measure of magnification. A
100mm lens has twice the magnification of a 50mm lens, so the shutter
speed needs to be twice as fast. However, at close range, you also need
to factor in the magnification on the film. To maintain sharpness when
handholding the camera, you would expect the shutter speed at 1:1
needs to be higher than at 1:2.
I don't know of a rule which takes magnification into account, but I'm
willing to invent one :-) Try this:

shutter speed = 1/focal length * (1 + magnification)

The first part of the formula is the familiar hand holding rule. At normal
distances, the magnification is small, close to zero, so it has no effect on
the shutter speed. As magnification increases, it increases the shutter
speed. For example, with a 50mm lens at infinity:
1/50 * (1 + 0) = 50 (1/50 sec)

the same lens at 1:2:
1/50 * (1 + 0.5) = 75 (1/75 sec)

and at 1:1:
1/50 * (1 + 1) = 100 (1/100 sec) 

Which suggests at life size, you should double the shutter speed. I don't
know how well this formula works in practice. My feeling is that the
shutter speed should be faster. At 1:2 I would double the shutter speed.
I would never shoot at greater magnifications - it is too difficult to hold
the camera steady enough to focus on such a small subject.
I rarely do hendheld closeups anyway. If I do, I always try to brace the
camera against a convenient solid object, or I use a tripod, or I use flash.
I've had best success with handheld closeups using my 55/2.8 micro, the
short focal length makes it easier to control camera shake (sometimes the
short focal length of 55micros is useful)

Hope this helps,
Roland 

Date: Mon, 22 Oct 2001 
From: "Eugene A. Pallat" eapallat@apk.net>
To: hasselblad@kelvin.net
Subject: Re: [HUG] a Hasselblad conscience ..

Austin Franklin wrote:

> > For vertical shots, rotating the camera counter clockwise 90
> > degrees so that their right arm is swinging in the breeze.
>
> Well, actually, I believe that is a better way...since you can anchor your
> left arm against your body for a steadier shot...

Rotate the camera clockwise 90 degrees.  Rest the base of the camera against the palm of the left hand, the right side in the palm of the right with the right index finger ready to trip the shutter.  Both elbows against the body and
squeeze the shutter.  Easier to do than describe.  I'm not as steady as I was 20+ years ago where I could shoot 1/2 second and 1 second hand held shots that way.

Gene Pallat


Newsgroups: rec.photo.equipment.medium-format,rec.photo.technique.misc,rec.photo.technique.people
Subject: Re: Technique of slow shutter hand-holding
From: Chuck Skinner cinema@gte.net>
Date: Wed, 31 Oct 2001 15:13:49 GMT

wpmills@Mills-USA.com (W. Paul Mills) wrote 

> Chuck Skinner cinema@gte.net> writes:
> 
>> Yes, I have used a Steadicam, and it works extremely well.
>> 
>> Excuse me for thinking that someone who calls a Steadicam a "gyro 
>> stabiliser" might be interested in knowing that it's not. Sorry to
>> have wasted time that you might have spent being a rude asshole to
>> someone else. 
>> 
>> Chuck Skinner
> 
> What principle does the stedicam work on?

My apologies if this gets posted twice; I lost connection while sending 
it the first time.

Vastly oversimplified:

The Steadicam places the camera at one end of a pole and a 'sled' 
comprised of a monitor and battery on the other. Slightly above the 
center point of the pole is attached a double gimbal mount, which is in 
turn attached to a spring-loaded arm. This arm is then attached to a 
vest.

The proper balancing of the springs and pivots results in the camera 
being suspended in mid-air, and able to rotate freely about all axes. 
The operator's arm (usually the left) parallels the Steadicam's arm, 
and is used to move the rig up, down, left, and right. The right hand 
holds the pole lightly, tilting and panning the camera.

The combined mass of the camera, monitor, battery, and pole tends to 
remain in place; the spring arm and mounting assures that it is 
relatively isolated from any body movements. This allows the operator 
to run, climb steps, etc. while the camera tracks along smoothly.

A greatly simplified version of this rig, the Steadicam Jr., is made 
for small, light camcorders. It dispenses with the vest and spring arm, 
and is simply held in the hand.

Although it's probably overkill for most still camera use, it does work 
because it increases the mass that you're holding (meaning it's harder 
to jerk around), and because the weight hanging rigidly below the 
camera tends to damp out any movement perpendicular to the axis of the 
pole.

You could simulate this with a still camera (and I have) by screwing a 
pole about three feet long to the bottom of the camera and adding a 
weight to the bottom of the pole. Holding the pole near the top will 
result in a pretty steady camera. The only problem is viewing your shot 
without touching the camera.

Interestingly, when Garret Brown showed a demo tape of the Steadicam 
prototype to Stanley Kubrick, Kubrick assumed there was a gyro involved 
somewhere (the demo didn't show the Steadicam itself). 

For more info, go to www.steadicam.com.

Chuck Skinner
-- 
web.tampabay.rr.com/skinner


From: "Joe Martin Cantrell" agiyo@cnnw.net>
Newsgroups: rec.photo.technique.misc,rec.photo.technique.people,rec.photo.equipment.medium-format
Subject: Re: Technique of slow shutter hand-holding
Date: Wed, 31 Oct 2001 

> I'll certainly brace myself as often as possible in low light
> situations, but what other tricks, such as implied above, are helpful?
>
> --It is impossible to state rules for all cameras; you look down into some
and sideways into others, and some were left handed, but a few of many
things which help are:

1.  Use a heavier camera with a soft shutter release.  A larger, softer
release button helps on older cameras with small buttons such as
Rolleiflexes.

2.  Make a tripod of your elbows braced against your torso, camera against
your face, if that's possible.  You don't have a pulse in your face; you
probably do in your torso.  Shoot verticals this way, too, not with your
right elbow up in the air like a sail.  I can't imagine why instruction
books almost always show the wrong way.

3.  Try to hold the camera like you love it, not with the tips of your
fingers.  Set it into your left palm, curl your hand around it so it feels
like part of you.  Do the same, as well as you can, with your right hand.
Try to press the shutter release as a gentle contraction of your whole hand,
action of your trigger finger against reaction of the heel of your palm.
Don't punch the shutter button!  Inhale, easy, and as you exhale, squeeze it
off.  Very like a firearm.

4. If you have something solid you can lean against, use it!
5. 
5.  Try to put your mind in a meditation with the subject, thinking through
the camera.  The more conscious you are of the mechanics of shooting, the
more likely you'll be to tense up.

If you work on those techniques and think about others, more of your
pictures will be blurred by subject motion than yours.  BTW, I have a
Graphlex and learned to shoot with a Speed Graphic.  The long levers of
their focal plane shutter releases are smooth pleasure to use.

Keep clicking, folks.
Joe

Newsgroups: rec.photo.technique.misc,rec.photo.technique.people,rec.photo.equipment.medium-format
Subject: Re: Technique of slow shutter hand-holding
From: mark@riparia.org (Mark Anderson)
Date: Thu, 01 Nov 2001 

Mark Anderson mark@riparia.org> wrote:

> zeitgeist blkhatwhtdog@yahoo.com> wrote:
> 
> >   but you could tell by reflecting a light off a
> > filter cap or mirror on a lens cap and watch how the spot of light jumps
> > around as you view it.
> 
> That's an excellent idea

I started playing with this.  There seems to be two motions to contend
with.  

1)  A slow movement of wandering aim.
2)  A fast short movement that seems to be related to pulse, even if the
camera is not held against the body.

I wonder which more often blurs the photo?

So far what looks good is to brace the camera against the hip bone.  It
doesn't pick up the pulse.  If held in the hands, holding it down
against a taught neck strap seems to help.  I haven't yet tried adding
weights or playing with a cable release.


-- 
     Mark Anderson - DBA Riparia Resources    www.riparia.org


Newsgroups: rec.photo.technique.misc,rec.photo.technique.people,rec.photo.equipment.medium-format
Subject: Re: Technique of slow shutter hand-holding
From: mark@riparia.org (Mark Anderson)
Date: Thu, 01 Nov 2001

Joe Martin Cantrell agiyo@cnnw.net> wrote:

>You don't have a pulse in your face; you
> probably do in your torso. 

This is my only kibbitz re what you wrote.  You do have a pulse in your
face, and you can transmit a pulse in the arms holding the camera also.
Visually I could see the pulse motion by playing with reflecting a light
off a mirror on the lens cap even if I held my camera to my face.  That
doesn't say whether the pulse was from the head, or thru the arms
though.

A very exagerated form of this is in people who have a leaky aortic
valve in the heart, so blood leaks back into the heart from the aorta
between contractions of the heart.  This causes a collapsing pulse, and
great differences in the systolic and diastolic blood pressure, hence a
great pulse pressure.  Essentially there's a pulsatile inflation and
deflation of the circulation that can literally cause the head, arms and
legs to visibly bob up and down.  To a lesser degree this is present in
all people.  In the severely afflicted with aortic insufficiency, such
as from Marfan's Syndrome, such as Abraham Lincoln had, the head and
limb bobbing may be enough, as a portrait subject, to cause blurring
during the long exposures of wet plate photography.  This effect is
visible in some portraits of Abraham Lincoln.

-- 
     Mark Anderson - DBA Riparia Resources    www.riparia.org


From: "thc" a2toothfairy@mw.mediaone.net>
Newsgroups: rec.photo.technique.misc,rec.photo.technique.people,rec.photo.equipment.medium-format
Subject: Re: Technique of slow shutter hand-holding
Date: Mon, 05 Nov 2001 

An ability to hand-hold a camera during slow shutter speeds varies with
respect to the particular individual and the particular shooting conditions.
Most photographers have good days and bad days for their hand-holding
ability.

Why not use a short roll (12-exposures) of film to test for your own
abilities?

Choose your own combination of film and lens, focus onto an unmoving target,
make a series of tripod-supported exposures and a series of hand-held
exposures at varying shutter speeds, and then analyze the results of your
own ability.

For your information:

Popular Photography (US) magazine (volume 63, number 3, March 1999, page 17)
featured an article about hand-holding versus using a monopod support.   Six
photographers used the same Canon "EOS Elan IIe" 35mm format SLR camera with
a 100mm-400mm f/4.5-6.7 zoom lens set at 400mm, focused at a mannequin head
at 26.5 feet distance, using Kodak MAX 800 color-print film.   A series of
monopod-supported exposures (at 1/8 second, 1/15, 1/30, 1/60, 1/125, 1/250
second) and hand-held exposures (same series, from 1/8 second - 1/250
second) were made (probably using short 12-exposure rolls of 35mm film), and
8x10-inches enlargements were made of the negatives for comparison.

- Results:
- The steadiest on that particular day of the six photographers was blurry
at 1/8 and 1/15, slightly blurry at 1/30, and sharp at 1/60, 1/125. and
1/250 second when hand-holding; was slightly blurry at 1/8 and 1/30, sharp
at 1/15, 1/60, 1/125, and 1/250 second when monopod-supported.

- The average of the six photographers was very blurry at 1/8 and 1/15,
slightly blurry at 1/30, and sharp at 1/60, 1/125, and 1/250 second when
hand-holding; was slightly blurry at 1/8, sharp at 1/15, 1/30, 1/60, 1/125,
and 1/250 second when monopod-supported.

- The poorest of the six photographers was extremely blurry at 1/8 and 1/15,
slightly blurry at 1/30, and sharp at 1/60, 1/125, and 1/250 second when
hand-holding; was very blurry at 1/8, blurry at 1/15, slightly blurry at
1/30, and sharp at 1/60, 1/125, and 1/250 second when monopod-supported.

In summary, these six photographers all were judged to be sharp at 1/60,
1/125, and 1/250 second exposures regardless of hand-holding or
monopod-support of a 400mm lens on a 35mm SLR camera body.  The 1/8 second
exposures by the steadiest photographer were judged to be either blurry
(hand-holding) or slightly blurry (monopod-supported).  The 1/8 second
exposures by the poorest photographer were either extremely blurry
(hand-holding) or very blurry (monopod-supported).  The 1/15 and 1/30 second
exposures were judged to vary from sharp (at 1/15 second, monopod-support,
by steadiest photographer; at 1/30 second, monopod-support, by average
photographer) to slightly blurry (at 1/30 second, both hand-held and
monopod-supported) to extremely blurry (1/15 second, hand-held, by poorest
photographer).

Another article in Popular Photography magazine (volume 63, number 6, June
1999, page 18) confirmed George Lepp's advice that the mirror-lockup feature
on a SLR camera body used with tripod-support generally gives more sharpness
at 1/8 - 1/60 second shutter speeds than not using the mirror-lockup with
tripod-support.

In short:
Monopod- and tripod-support generally outperform hand-holding in the 1/8
second - 1/15 second -1/30 second exposure range (no big suprise here), but
even a tripod-supported SLR camera gains additional sharpness (up to a 227%
gain in sharpness, when measuring line pairs per millimeter resolution) when
the mirror-lockup feature is utilized in the same exposure range.

> Erich Salomon pioneered available light candid photography in the late
> 1920's with the Ermanox.  He often needed 1/4 sec. or longer exposures,
> and initially couldn't use a tripod since he needed to remain incognito.

The (Ernemann A.G. Dresden) Ermanox plate camera of 1924 had either an f/2
100mm or an f/1.8 85mm Ernostar lens, and offered 1/20 second - 1/1,000
second shutter speeds (as described in Rosenblum's "A World History of
Photography," and in McKeown's "Price Guide to Antique & Classic Cameras"),
so Salomon probably didn't have available 1/4 second exposure times with
that particular camera. Maybe the unsharpness and blurriness inherent to his
longer shutter speeds were camouflaged somewhat by the larger film format
(4.5 x 6 cm) of his camera. [Also, I'm uncertain about what size were
printed from Salomon's plates. A 4.5-inch x 6-inch print would be about 2.5x
diameter enlargement. A 35mm frame requires more enlargement for the same
size print.]

> Sure the critical eye will see that some of Weston's famous portraits
> are not critically sharp, yet they're quite good and easily acceptable
> to 8x10.
{snip}
> I'll certainly brace myself as often as possible in low light
> situations, but what other tricks, such as implied above, are helpful?
>
It has been shown that tripod-support and mirror-lockup are the gold
standard for truly sharp 35mm SLR photographs.
Thus, any technique not utilizing those two features will result with
photographs deficient in some degree of sharpness.
You state that Weston's unsharp prints are acceptable to you.

So, the question actually reduces to:
What degree of unsharpness are you willing to allow your prints to exhibit?
[Robert Capa's blurry photographs of 1944 D-Day invasion of Normandy exhibit
a captivating subject matter that overcomes their technical problems.]
The correct answer needs you to experimentally determine an exposure
technique that is acceptable to you.
_________

mark@riparia.org says...
> Edward Weston made many of his 4x5 Graflex shots hand-held at 1/10 sec.
> Erich Salomon pioneered available light candid photography in the late
> 1920's with the Ermanox.  He often needed 1/4 sec. or longer exposures,
> and initially couldn't use a tripod since he needed to remain incognito.
> Today I see a photo of him holding his camera against his torso with his
> left hand and holding a cable release with his right hand.
>
> Sure the critical eye will see that some of Weston's famous portraits
> are not critically sharp, yet they're quite good and easily acceptable
> to 8x10.  How many of use can say the same with 1/10 sec. handheld
> exposures?
>
> I've never thought of using a cable release while hand holding.  So, I
> wonder...
>
> Can holding the camera against the chest or abdomen be a more stable
> position than braced against the face?
>
> Is waistlevel viewing inherently more stable?
>
> Is a cable release while hand holding in such conditions advantageous to
> an experienced gentle squeeze on the shutter button?
>
> I'll certainly brace myself as often as possible in low light
> situations, but what other tricks, such as implied above, are helpful?
>



From: "Lars Soerink" lars@soerinkNOSPAM.nl>
Newsgroups: rec.photo.equipment.medium-format,rec.photo.technique.misc,rec.photo.technique.people
Subject: Re: Technique of slow shutter hand-holding
Date: Tue, 6 Nov 2001 

Not  many seem to know this:

Place your left hand on your right shoulder and push your elbow upwards.
Place the lens of the camera on your elbow, gently pressing the elbow
downwards. Of course you can not focus manually this way, but this trick
provides an extremely stable platform for slow shutter speed photography. I
use this technique often and it works great for me. It looks a bit silly,
but who cares?

With kind r,gards,
Lars Soerink

Lars Soerink - Nature, wildlife and documentary photography
Website: http://www.soerink.nl
E-mail lars@_NoTrash_soerink.nl    remove notrash _\|/_



From: "Charlie Goodwin" cgoodwin@conknet.com>
To: hasselblad@kelvin.net>
Subject: Re: [HUG] Vibration at Slow Shutter Speeds with Focal Plane Shutters
Date: Sat, 17 Nov 2001 

Replying to Q.G. de Bakker, who wrote, "The added mass of a camera bag
swinging freely underneath the tripod does not do a lot, if anything at all,
to increase inertia. In fact, having extra mass swinging around can even add
to instability,  depending on how it is fixed.   It does help lowering the
centre of gravity though, so if you are afraid the tripod may fall over, by
all means, hang a fully laden bag from your 'pod"



Sorry, but I must suggest J.P. try testing it...Hanging a camera bag under
the tripod is reported to help a lot of folks, but the key is whether it
helps him.   A test will determine that.

No to mention that the function is not to increase the inertia of the
tripod, which as Q.G. de Bakker astutely observes, is only slightly
enhanced, but rather to use the downforce of the greater weight to more
rigidly connect the tripod to the great and stable mass of the earth.   Once
the tripod is functioning as a more firmly attached part of the ground
beneath, it will usually gain stability.   But, test, test, test.

Charlie



From: "Charlie Goodwin" cgoodwin@conknet.com>
To: hasselblad@kelvin.net>
Subject: Re: [HUG] Vibration at Slow Shutter Speeds with Focal Plane Shutters
Date: Sun, 18 Nov 2001 

Will this be the last word?

Maybe.

After Q. G. DeBakker's last message, I was determined to settle this
question of vibration and hanging camera bags once and for all.   After all,
my pride of knowledge was at issue.

To quickly create a sensitive test of the effects of hanging (or not) a bag
off the tripod, I set up a 500C in my studio on a moderately sturdy tripod,
competent for a 2 1/4 square and moderate lenses.   I attached a cable
release and balanced a glass of water on top of the camera.   I trained a
tungsten spot with the beam cut down to a narrow slot by barndoors  on the
waterline in the glass.   With the studio darkened I adjusted the spot till
I saw a sharply defined refracted beam of light that showed on the floor.
The water in the glass had the effect of magnifying the vibrations in the
camera/tripod system, and the refacted beam functioned as a very sensitive
indicator, the poor man's seismometer.   The slightest vibrational input to
the camera sent the beam of light dancing over a 10 or 12 inch range for
several seconds, making it easy to "see" camera movement.   Even holding the
cable release any less than rock steady would induce a tremor in the beam.

First I fired the shutter a a second with the simple camera/tripod system.
As expected, the shutter (and auxilliary shutter)induced wild movement of
the beam on the floor.   Delighted with the beauty and elegance of the
testing proceedure and ready to vindicate the common wisdom of hanging the
camera bag down off the center of the tripod, I retested with the bag
weighted system.   Egads!   Another wildly flailing beam of light.   As far
as I could see, the camera was moving just as much.   A few subsequent
variations seemed to confirm an ugly truth; that the weight of a camera bag
did not improve the steadiness of my setup.   Crow is not a traditional
Thanksgiving dish, but this year I shall make every effort to savor it....

Seriously, I do wonder about whether weighing down the tripod might make a
positive contribution on softer, more unsure footings.   Has anyone any
evidence of whether extra weight on a tripod on say, a deep grassy turf,
where the tripod bounces or floats on a springy mat  of vegetation a bit
when you get it set up, is helpful or not?

One piece of common wisdom that survived utterly intact is that of the value
of the mirror lockup.   Eliminating mirror and auxiliary shutter movement
dramatically reduced the vibrations in the system.

There is objective reason doubt the value of resting one's hand on the
tripod; the vibrations it induces are quite apparent.   In fact, the dance
of the beam of light makes me a great deal more aware of the unfortunate
sensitivity of the camera/tripod system to any external mechanical jostling,
no matter how seemingly tiny.

Happy Thanksgiving and steady pictures,

Charlie


Date: Mon, 19 Nov 2001 
From: Daniel Taylor lightsmythe@yahoo.com>
Subject: Re: [HUG] Vibration at Slow Shutter Speeds with Focal Plane Shutters
To: hasselblad@kelvin.net

Charlie,

excellent. thank you for expending the energies toward
investigation of this problem. I did much the same
thing in an engineering study on Canon Image
Stabilization lenses for a magazine article I was
asked to write. I discovered the preponderance of
photo-lore and myth propagated by most who had never
taken the time to validate any of their rhetoric. I
found Leica and Hasselblad pundits who could recite
MTF plot data, had memorized Wildi's and Put's books,
steeped themselves in anecdotal arcanum, and used the
forums as their stage to enlighten the world. the
problem is that they hadn't actually used the
products, didn't own the products, and would
vociferously refute anyone whose observations didn't
match their own. forums are a culture. they don't
necessarily reflect anything other than a group of
catalogue absorbers and ebay sleuths.

my studies have always shown the ballhead or camera
pivot was the most critical component in the linked
mass. the best tripod always had secondary
contributions in comparison to the camera attachment.
the Arca Swiss B1 was a stellar performer in my tests.

thank you once again for your efforts.

Daniel Taylor
Lightsmythe Studios
Oregon, USA



Date: Mon, 19 Nov 2001 
To: hasselblad@kelvin.net>
From: Henry Posner/B&H; Photo-Video henryp@bhphotovideo.com>
Subject: [HUG] Re: Vibration at Slow Shutter Speeds with Focal Plane Shutters

you wrote:
>You didn't broach the subject of dampening.

Nor have we touched on the clear benefits of wood tripods over metal or 
carbon fibre, as wood transmits far less vibration.

>(And you can sometimes increase the dampening by pressing on the tripod

The benefit of a well placed sandbag on top of the camera or lens at the 
point of balance cannot be overlooked either.

--
regards,
Henry Posner
Director of Sales and Training
B&H; Photo-Video, and Pro-Audio Inc.
http://www.bhphotovideo.com


Date: Mon, 19 Nov 2001 
From: Phil Lindsay fotophil@pacbell.net>
Subject: Re: [HUG] Vibration at Slow Shutter Speeds with Focal Plane Shutters
To: hasselblad@kelvin.net

Hi to all vibrating photographers:

I have been using one of the all- time champ of camera vibration - the big Pentax 67!!  This thing almost jumps off the tripod when shot without the Mirror Lock Up!!

In my testing, I found that a rather heavy (4 pounds or so) lead shot filled "Bean Bag" placed over directly over the prism worked wonders for the shutter induced vibrations at 1/4 to 1/.30 sec. I'm using a series 400 Gitzo with big
ball head. It sure adds weight to the camera pack in the field but I think it's worth it.

I've never tried hanging a camera bag because I use a back pack and besides the tripod has no means of attachment.

Phil


Date: Tue, 20 Nov 2001 
From: The Dalton Gang NikonF2@pacbell.net>
Subject: [HUG] Vibration at Slow Shutter Speeds
To: hasselblad@kelvin.net


I too have used a sandbag over the prism with excellent results.  When using my 553ELX,  I constructed a leather sling for my sandbag and hang it between the legs of my Bogen (Manfrotto) tripod.  This works very well but not as well as placing the sandbag on top of the camera but does allow easier access to the camera for changing settings.  I came up with this idea after almost losing my 553ELX and 250mm lens due to a high center of gravity.  

If you use this arrangement, I recommend the sandbag be as close to the ground as practical to keep the center of gravity as low as possible.  

Happy Thanksgiving and Happy Shooting!


Date: Tue, 20 Nov 2001 
From: "Anne F. Bellenger" cyclist2@strato.net>
To: hasselblad@kelvin.net
Subject: Re: [HUG] Re: Vibration at Slow Shutter Speeds with Focal PlaneShutters

> A sandbag on TOP of the camera?
Well, in the 35mm world, sometimes we put a beanbag on top of a
telephoto lens to steady the whole thing. Works too.

Anne


Date: Tue, 27 Nov 2001 
Subject: [HUG] focal plane shutter thoughts
From: George Day george@rdcinteractive.com>
To: hasselblad@kelvin.net>

Folks,

Yesterday I mentioned this recent review of the P67II on luminous-landscape:

http://www.luminous-landscape.com/pentax67ii.htm

The discussion of tripod/ballhead use and its effects with a large focal
plane shutter is dramatic.  I'm wondering: has anyone done a comparison of
this kind with the longer FE lenses?  Or even the 110?


Date: Thu, 16 Aug 2001 
To: HUG hasselblad@kelvin.net>
From: Jim Brick jim_brick@agilent.com>
Subject: Re: Non Hasselblad Advice From Contax Users

you wrote:
>Austin Franklin wrote:
>
> > > > There is no question that the quality of the optics is equal.
> > >
> > > The Zeiss/Contax lenses might even be better than the Zeiss/Hasselblad
> > > lenses.
> >
> > OK, O.G., I'll bite... why?

from: "Q.G. de Bakker

>Simple. Newer designs. Like the APO 120 mm Makro-Planar available for
>Contax.


Isn't the Contax "new" design for the lens meant for 645? How can this be 
extrapolated into a comparison with a Hasselblad lens? Which also has a 
shutter between the center elements.

I personally believe that extraordinary measures would have to be taken to 
produce images with the Contax 120 that would be "noticeably" better than 
the Hasselblad 120. Noticeably meaning something that you and I could 
readily see on a print.

And don't forget that the Hasselblad lens has a leaf shutter that will 
always perform better than a large focal plane shutter. Especially for 
close-ups where vibration is magnified and shutter speeds are slow because 
f/stops are small (close-up DOF) and film speed is slow (high resolution.)

I believe comparing these lenses is futile and meaningless.

Jim

From: "Bert Sirkin" BSirkin_no@spam_attbi.com>
Newsgroups: rec.photo.technique.nature
Subject: Re: Factors affecting sharpness
Date: Tue, 25 Dec 2001 

THe physical length of the lens makes a big difference.  Vibration actually
travels down the lens.  The physically longer the lens, the worse it is.
Thus a 600mm refracting lens (the typical type of lens) would be worse than
a 600mm reflecting lens (which is much shorter).

Cooincidentally I did a test earlier today wher I shot 1/15 second and 1/4
second using 300mm, 300mm w/1.4x and 300mm w/2x with Velvia where I did 3
shots each: cable release, cable release while pressing on the lens above
the tripod, and mirror lockup.  When I get the slides back I'll do hi-res
scans of the center portion of each and display the sharpness results on my
web site (probably in a month from now).

Different cameras will yeild different results because of differences in
mirror vibration.  I have an F5, which supposedly has a very quiet, low
vibration mirror and a very solid tripod and head..  I don't know if my
results will by typical, but it will be interesting to see the results.

It's real hard to avoid those shutter speeds.  I shoot Velvia regularly with
a 300mm/f4 and a 1.4 and 2x telextender.  RARELY do I shoot much above 1/15!
I use mirror lockup whenever I can, and that works really well.

regards,
Bert Sirkin
Web Gallery: http://www.photobert.com/page1.asp
Nikon CheatSheets: http://www.photobert.com/cheatsheet.htm

(please remove _no   spam_ from email address)
"Henry_Barta" hbarta@shell-1.enteract.com> wrote 
> Bert Sirkin BSirkin_no@spam_attbi.com> wrote:
> > At shutter speeds between about 1 second and 1/30 second, the vibration
of
> > the cameras mirror can have a visible impact on your images.
>
>     I've heard this far too many times to conclude that it is *not*
>     going to be a problem with my equipment. Will the 'critical'
>     shutter speeds differ with equipment? Will different lenses
>     have problems at different shutter speeds? Of course, a longer
>     lens will be more sensitive due to the magnification, but will
>     the weight of different lenses also have an effect? (My equipment
>     is a Nikon F100 and various new and old lenses.
>
>     How could I best test for this? What I would have in mind is
>     to print some text (black and white) perhaps with some vertical
>     and horizontal lines an fix it to some convenient internal
>     wall.
>
>     Camera would be in full manual, of course. I could vary aperture
>     to provide reasonable exposure at different shutter speads. As
>     well, I could vary lighting to increase the range. Then, I
>     suppose, I would want to test at 1 stop intervals from 1 second
>     to 1/30 (or a wider range, just to be sure.) Should I test
>     several lenses? I have a choice if (Nikkor) 50mm, 24-120 zoom,
>     135mm.
>
>     And of course, I would be testing with the camera on a tripod.
>
>     Is there a better way to test? Should I test or just avoid
>     these shutter speeds?
>
>     thanks,
>     hank
>
> --
> Hank Barta                            White Oak Software Inc.
> hbarta@enteract.com                   



From: "Tommy Huynh" tommyphuynhtakeoutthisspamblokr@yahoo.com>
Newsgroups: rec.photo.equipment.35mm
Subject: How VR works(Was: A whole day and no mention of new Nikon?)
Date: Thu, 17 Jan 2002 

"Bruce Murphy" pack-news@rattus.net> wrote:
> > Some people said that the AF sensors were used to detect vibration,
which is
> > not true.  Nikon uses solid state gyros just like Canon.
>
> Really? Did you actually have proof of this, or is an assertion along
> the lines of the existance of a "solid state gyro". People can't have
> "VR is all in the lens" *and* "The F mount contacts can't do AF-S
> and VR because the AF-S contacts are used to transmit VR information"

Cripes, this just won't die.  Alright, I think this rumor started when Moose
Peterson wrote this:

"The VR technology only works on camera bodies with the five AF sensors, the
D1, F5, F100 and N80. The five sensors are part of the VR operation which is
why it's required."

http://www.moose395.net/gear/mcb80400vr.html

Some people read this and took it to mean that the AF sensors were being
used to measure camera shake which simply is not true.  Keep in mind that in
order to compensate for camera shake using optical image stabilization (as
opposed to the digital systems used in some camcorders), you want to be able
to quantify the vibration by measuring angular velocity, then use this data
to calculate the translation needed for the corrective lens, and drive the
lens as fast as possible, usually within 1ms or so.  Trying to solve for
angular velocity from the image shift over the AF sensors and from lens
information, while needing to establish focus first (which is hard enough
already), all within a few milliseconds, is practically impossible and makes
no sense when you can measure it much more quickly, accurately, reliably and
directly using gyros, not to mention it requires much less computation.  And
that's why they are used.  From Popular Photography:

"While both manufacturers are tight-lipped about the specifics of their
systems, the two are, fundamentally, quite similar. Solid-state motion
detectors sense camera movement along horizontal and vertical axes, x and y.
The detectors determine the frequency and direction of the shake, and
communicate this data to a floating correcting lens element (or group)
that's placed in the middle of the optical path. This lens moves in x and y
directions in compensatory sync with the camera shake."
http://www.popphoto.com/Camera/ArticleDisplay.asp?ArticleID=59&page;=2

As to whether VR is "all in the lens," all the necessary *main* components
other than power are in fact "in the lens*.
http://www.nikon.co.jp/main/eng/society/tec-rep/image/08fig3-e_i.gif
http://www.nikon.co.jp/main/eng/society/tec-rep/tr8-vr_e.htm
Thanks to Don Ferrario for the links.  Whether Nikon ties in some other
obscure function with the body so that it only works with a new body, I
wouldn't doubt it.  And why not?  Camera companies do it all the time so you
have to buy their latest and greatest stuff.  It's part of keeping your
corporation alive, although it drives us nuts.  Same goes for many other
things you buy, especially software.  Canon does the same thing.  The A2e
disables ECF when you tilt it vertically.  Why?  Perhaps so you'll buy the
EOS 3 or Elan II when it came out but ask Canon and they say it's because
there is not enough memory to store a profile for your eye when it is held
vertically.  Of course this is BS because there are 4 other memory slots for
eye profiles that could easily be used, and even without a seperate profile,
the ECF hardware in the A2e (after you rig it) is perfectly capable of
working in vertical format (for my eyes anyways).

As for why there hasn't been a lens with AF-S and VR?  Another speculation
thrown around here was that there are not enough contacts on the F mount. I
think this is also false because:
1)  Nikon could very easily multiplex the data channels.  VR is largely a
self contained system in the lens.  The amount of communication needed with
body is minimal (as we've already seen).
2)  It would not be that hard to add more pins to the F mount.
3) An engineer at Nikon told me it's not:)

It's really anybody's guess for what the actual reasons are.  Patents would
be my main guess.  This is speculation on my part but it appears to me that
for Nikon to use VR or AF-S, they have to negotiate license agreements with
Canon, and Canon might be unwilling to allow Nikon to use both on the same
lens (at least up until this point).  Now everybody knows Canon owns a bunch
of patents for piezo motors (along with Sharp I think), but some people
think Nikon doesn't need Canon patents for VR because their P&S; Zoom Touch
with VR came out in 1994, but Canon actually had been doing IS long before
that in their binoculars, and if I remember right, they had an image
stabilized lens prototype in the late 80s.  Also keep in mind that Canon
guys are extremely gung-ho when it comes to patents.  Look them up at the
patent office and you'll find their name "Canon Kabushiki Kaisha" in the top
5 companies in terms of number of patents awarded in the US.


From leica topica mailing list:
Date: Sun, 30 Dec 2001 
From: Jim Brick jim@brick.org
Subject: [Leica] Mirror flapping and tripod dissertation

Henry Ting wrote:

>  but quite frankly mirror flapping is
>only detrimental to closeup macro.


Actually, the SLR mirror effects ALL photographs taken with a shutter speed
between a 1/30 and 1/4 second. Not just close-ups. It kills the recording
of fine detail. The reason is that the mirror hits the top and the
diaphragm closes down just before the shutter opens. The mirror vibration
is at its peak just when the shutter is open and the vibration lasts for
roughly 1/30th second. Long enough to be fully captured with a shutter
speed between 1/30 and 1/4 second. Shorter shutter speeds (1/60 and 
higher) are over before the vibration wave hits its peak. With longer exposures
(1/2 second and longer,) the vibration is a very small percentage of the
total exposure time and therefore is not recorded.

Carbon fiber and wooden tripods will help dampen camera vibrations by
absorption while steel and other all metal tripods tend to echo the
vibration, and in some cases, amplify the vibrations putting the vulnerable
shutter speeds all the way down to 1 second. The vibration wave sent
through the metal tripod echoes back into the camera as a second vibration
thus extending the vibration period.

Throw a rock into the center of a small pond. The waves radiate out from
the rock hit, toward the bank then echo back, from the bank, to the center,
where the rock hit. It is the same in a metal tripod. The camera vibrations
radiate out (down the legs) and echo back to the camera. This does not
happen in either a wooden tripod or a carbon fiber tripod.


If you have an SLR without MLU and want to photograph in the 1/30 to 1
second range, buy wood.

Jim


From nikon mf mailing list:
Date: Tue, 01 Jan 2002 
From: "Norman Vujevic Sr" pymatuningcreek@hotmail.com
Subject: Re: Beanbags any


A bag of lead shot weighs 25#. Thats a lot of extra weight. Get a bag of
beans,leave them in the plastic bag and place the whole bag inside the
cotton bag from the shot and sew shut. It will remain waterproof until you
poke a hole in it. Norm


From nikon mf mailing list:
Date: Tue, 01 Jan 2002 
From: Tsun Tam tsuntam@bellatlantic.net
Subject: Re: Beanbags any?

Might I suggest that for the stuffing for these bean bags that you use the
small polyethylene pellets used for injection molding. They won't soften
until your subject them to temperatures that are well above the boiling
point of water, so it may be washed safely in a washing machine -- though
I wouldn't recommend that you dry the beanbags in your drier unless you
set it to the delicate/perma press setting.

These pellets are approximately 1/8 in size and is WATERPROOF,
non-absorbent, not toxic, unbreakable and cheap. What more can one ask for
with the stuff that goes inside a beanbag? Forget about styrofoam
(difficulty in cleaning), lead shots (toxic) or glass beads (breakable)!

Tsun Tam


From leica topica mailing list:
Date: Sun, 30 Dec 2001 
From: Jim Brick jim@brick.org
Subject: [Leica] Mirror flapping and tripod dissertation

 Henry Ting wrote:

>  but quite frankly mirror flapping is
> only detrimental to closeup macro.


Actually, the SLR mirror effects ALL photographs taken with a shutter speed
between a 1/30 and 1/4 second. Not just close-ups. It kills the recording
of fine detail. The reason is that the mirror hits the top and the
diaphragm closes down just before the shutter opens. The mirror vibration
is at its peak just when the shutter is open and the vibration lasts for
roughly 1/30th second. Long enough to be fully captured with a shutter
speed between 1/30 and 1/4 second. Shorter shutter speeds (1/60 and 
higher) are over before the vibration wave hits its peak. With longer exposures
(1/2 second and longer,) the vibration is a very small percentage of the
total exposure time and therefore is not recorded.

Carbon fiber and wooden tripods will help dampen camera vibrations by
absorption while steel and other all metal tripods tend to echo the
vibration, and in some cases, amplify the vibrations putting the vulnerable
shutter speeds all the way down to 1 second. The vibration wave sent
through the metal tripod echoes back into the camera as a second vibration
thus extending the vibration period.

Throw a rock into the center of a small pond. The waves radiate out from
the rock hit, toward the bank then echo back, from the bank, to the center,
where the rock hit. It is the same in a metal tripod. The camera vibrations
radiate out (down the legs) and echo back to the camera. This does not
happen in either a wooden tripod or a carbon fiber tripod.


If you have an SLR without MLU and want to photograph in the 1/30 to 1
second range, buy wood.

Jim


From minolta mailing list:
Date: Thu, 29 Nov 2001 
From: "Mark Groep" mark.groep@ramasset.co.uk
Subject: Shutter vibration

Hi all,

We all know about the merits of mirror lock-up to reduce vibration
induced problems with sharpness.  Has any of you got experience with
shutter vibration?  I find that at least as bad as the mirror
vibration, which maybe explains about the threads of blurred
telephoto images with mirror lock-up.  Also, are some camera's more
vibration prone than others in the Minolta line-up?  I can't help but
feel that my XD-7 / XD-11's vibrate a little more than my XGM because
the vibration of the verical leaf shutter coincides with the vertical
movement of the mirror.  Can anyone suggest which is the
least "vibrating" mirror/shutter manual Minolta?

Mark



From Rangefinder Mailing list:
Date: Thu,  7 Mar 2002 
From: Winfried Buechsenschuetz w-buechsenschuetz@gmx.de
Subject: RE: Werra Rangefinder Camera

Clayton Ravsten wrote:
> Has anyone had experience with the Werra Rangefinder Cameras?  Any
> information performance of this camera would be appreciated.  Thanks.

An australian guy who bought a Werra in the 60s told me about it. He
said he was surprised about the sharpness of the pics and first thought
this was due to the Tessar lens (which has an excellent reputation).
Later he found that it was due to the almost non-existing camera shake.
The Werras have a very special leaf shutter which is probably the only
one which can run at an actual speed of 1/750 (at full aperture). It is
inherent to this design that it won't cause any camera shake since the
blades rotate continously (on all other leaf shutters the blades are
stopped when fully opened and forced to return).


There are quite a few different models of the Werra line, I am not sure
whether they all have this shutter. I think on

http://www.tigin.de

you can get more information.

Winfried



From: Jonathan Sachs jsachs@dl-c.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Pentax 67, how heavy tripod needed?
Date: Tue, 05 Mar 2002


The focal plane shutter is a problem, which, unlike the mirror has no
easy solution. The problem occurs when you use a range of shutter
speeds such that the front curtain travels across the film and stops
with a massive thunk and starts the camera shaking before the rear
shutter passes across the film. At high shutter speeds, the rear
curtain passes across the film before vibrations from the front
shutter can build up. At low speeds, the vibrations die down for most
of the exposure. Since the maximum flash sync is 1/30 sec., this is
the exposure speed at which the rear curtain starts across the film
just as the front curtain reaches the other side.  At around 1/8 -
1/15 sec., you have the worst vibration effects. Using long lenses
with the P67 (e.g. 300mm up) at these shutter speeds requires a very
massive tripod and head. This problem has been well documented and I
have experienced it myself on a number of occasions using a Gitzo 1228
and B-1 head.

Jonathan Sachs


From: Jonathan Sachs jsachs@dl-c.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Pentax 67, how heavy tripod needed?
Date: Wed, 06 Mar 2002


The problem just starts to show up with the 200 -- it's much more
pronounced with the 300 which is much longer, heavier and more prone
to side-to-side vibrations unless it is really tightly restrained.
Using the 300 with 2X extender is a real problem without a heavy
tripod, especially near the 1/8-1/15 sec. range.

Jonathan Sachs

"Brian Ellis" bellis60@earthlink.net wrote:

>Strange, I've been using the camera for seven years with the 45 mm, 55 mm,
>75 mm shift, 105 mm, 135 mm macro, 200 mm, and 200 mm with 1.4 extender (280
>mm) at shutter speeds ranging from probably a minute or two up to 1/1000 and
>have never experienced any of the problems mentioned in these two threads
>using a fairly light tripod (Bogen 3021 with Arca Swiss B1 head).   Indeed
>if the problems mentioned here were actually serious problems it seems
>doubtful that anyone would ever buy the Pentax 67 camera - I know I
>wouldn't.




From: "JL" jacklu2@yahoo.com
Newsgroups: rec.photo.technique.nature
Subject: Mirror-flop/shutter-release vibration test and results
Date: Mon, 23 Apr 2001


Has anyone tested their setup for mirror-flop and/or shutter release
vibration?

I figured I had "some" so I did a simple test by taking a series of pictures
of pin holes in tin foil placed over a flashlight.  This method quickly
reveals I had camera shake and at what shutter speeds it was a problem.  I
also tested several methods to reduce the vibration and was very surprised
by the results.

I've posted the results at:
http://home.cinci.rr.com/creek/camera_shake_test.htm.

I would be very interested to hear what others have found.
Thanks,
Jack


From: "Mark Erickson" spam@westerickson.net
Newsgroups: rec.photo.technique.nature
Subject: Re: Mirror-flop/shutter-release vibration test and results
Date: Mon, 23 Apr 2001


Interesting results....  There is also an article on this subject by Bob
Atkins at:

   http://www.photo.net/photo/nature/mlu

--Mark



From: Ken kence@idworld.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Which three lenses for 6x6?
Date: Wed, 03 Apr 2002


Mxsmanic wrote:
> "Ken" kence@idworld.net a ,crit 
> > Photographers would do well to study a sniper's
> > techniques.
>
> Hmm ... not a bad idea.  Any place on the Web where I could look this up?

Obviously, some aspects of marksmanship won't apply to photography but
some will. Here's a start;

http://www.geocities.com/pentagon/7719/snipermain.html

http://pages.zdnet.com/remingtonsniper/remington700rifleclub/id16.html


> > Excellent shots, BTW.
>
> Thanks.  Which photos are we talking about?

http://www.smallevents.com/scan.jpg



From: "Jerry Fusselman" cmesa@ix.netcom.com
Newsgroups: rec.photo.equipment.large-format,rec.photo.equipment.medium-format
Subject: Re: Tripod recommendation?
Date: Mon, 13 May 2002 

Q.G. de Bakker writes
> The carbon versions of the Gitzo range are lighter than the full metal ones,
> but cost a lot more too. Myself, i believe in the importance of having mass
> in a tripod (and not just structural rigidity), so they are not for me, but
> maybe they are just what you're looking for?

Mass is not that important when it comes to carbon fiber. Carbon fiber tripods
can be excellent even though low in mass. My experiments convince me that
carbon fiber tripods can surpass far heavier tripods in terms of keeping a 
camera steady.

I compared sharpness with an EOS 200 f/1.8L (lens alone is 6.6 poinds) on a
Wimberly Sidekick with Velvia and mirror lockup in these three setups:

A. Big heavy Benbo XL with NPC Pro head.
B. Gitzo 1325 (no center column) with a 22-year-old 15-ounce Gitzo head.
C. Gitzo 1325 with NPC Pro head.

Setup A weighs 10 pounds more than B, yet B is gave sharper results (based on
USAF 1951 resolution test charts) with my 200 (both with and without my EOS
doubler) at every aperture I tested (up to f/11). I was hoping not to lose too much
sharpness when hiking with setup B, so I was shocked and delighted that the 1325
with my tiny, inadequate-looking Gitzo head did so well.

Then I compared B to C, and C is even better. In terms of lp/mm, B is almost
15% better than A on average, and C is more than 5% better than B on
average. My Benbo XL still gets plenty of use, because it can do things that
my 1325 cannot do.

It seems that somehow, carbon fiber tripods seem to deaden vibrations,
or they do some other magic, that results in higher-resolution images
than should be possible if tripod mass was the main consideration.

I believe that no one should reject a four-pound carbon fiber tripod for fear
that image sharpness must suffer compared to a 14-pound conventional tripod.

Jerry Fusselman



From: "William E. Graham" weg9@attbi.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Handholding 200mm lens
Date: Sun, 12 May 2002 


It also helps if you have some solid object nearby to steady
yourself against...A telephone pole, or the wall of a
building, or a tree for instance. I have also had good
results sitting down with my elbows resting on a table. If
exact composition isn't too important, you can place the
back of your camera against a wall, and fire the shutter
from the side, without looking through the viewfinder. When
you do this, it's the equivalent of using a tripod. You can
sit down on the ground, hunch up and rest your elbows
against your knees. Marksmen who shoot rifles will
frequently use tricks like this. You can also wrap the
camera strap around your arms or body and hold it taunt to
help steady your camera just as a marksman will wrap his
rifle sling around his arms.....

"Jon" newbie@spamfree.com wrote
> I've read that the rule for handholding shots is that the shutter
> speed probably should not be slower than 1/60 sec for hand-
> held shots.  Is this true on both ends of the camera? What I
> mean by this is, if I am handholding a 200mm and the image
> through the viewfinder at 100-150 feet is shaking a little (I
> can see the regular shaking that my heartbeat causes), am I
> still safe shooting at 1/60, or need I shoot at a faster shutter
> speed?
> Jon



Date: Fri, 24 May 2002
From: "Mxsmanic" mxsmanic@hotmail.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Does the 1/focal length rule hold for MF?



"Leonard Evens" len@math.northwestern.edu a ,crit...

> Can someone explain what the rationale of
> this rule is?

Most camera shake is rotational, with the movements of the photographer
causing the camera body and lens to rotate about a point and sweep through
some angle in the image field.  The longer the lens, the greater the
distance on the negative covered by a movement through a given angle, and so
the slowest permissible shutter speed to freeze movement perceptibly goes up
as the focal length increases.

Translational movement of the camera, such as up-and-down vibration, has
virtually no effect at all on the image being recorded, if the scene being
photographed isn't too close, but here again, the longer the focal length,
the more obvious the movement.

 It would seem to me that the relevant thing would
> be angle of view.   This is related to the ratio of
> the diagonal of the format to the focal length.   So a
> rule which applies to 35 mm shouldn't simply use
> focal length when switched to medium format.

I've been wondering the same thing.

> Also, it seems to me there might be some difference
> between leaf and focal plane shutters in how much
> camera or subject movement is acceptable.

Fast movement of a subject causes image distortion with a focal-plane
shutter, but not necessarily blurring.  Subject movement does not produce
distortion with a leaf shutter, although blurring remains just as much a
problem.

> I've always found that with a TLR I could shoot
> down to 1/60 (using an 80 mm lens) without trouble
> and down to 1/30 with some care.

I've gotten shots at 1/8 with both 35mm and (I think) MF gear, but it's
largely a matter of luck at those speeds, I think.  Even the slightest
amount of bracing hugely increases stability.



Date: Sat, 25 May 2002
From: "Mxsmanic" mxsmanic@hotmail.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Does the 1/focal length rule hold for MF?


"Robert Monaghan" rmonagha@smu.edu a ,crit...
> according to some accelerometer tests performed
> by Dr. Kdudrzyk (Photography for the Serious Amateur,
> Eugen J. Skudrzyk, charts..) the larger mass of
> medium format cameras significantly reduces the
> amount of vibration and shake compared to smaller
> mass (<1 kg) 35mm SLRs

I have always found that heavier cameras tolerate handheld shots much
better, unless they are so heavy or so awkwardly held that they induce a
muscle tremor.  The few excellent shots I've obtained at 1/8 were generally
with a heavy F5 or with a Leica M, which is heavy for its size and can be
easily held still.

Also, at higher shutter speeds, I've obtained handheld results with MF that
I cannot distinguish from tripod shots, even under a microscope.  Beyond a
certain speed, it really doesn't matter whether you have a tripod or not.



From: "Q.G. de Bakker" qnu@worldonline.nl
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Does the 1/focal length rule hold for MF?
Date: Sat, 25 May 2002


Mxsmanic wrote:

> Looks great ... certainly for a full-frame shot I don't see any sign of
> softness at all.  Of course, if you enlarge it to wall size and view it from
> a foot away, maybe you'd see something, but I don't really know.
>
> Was this 250mm one of those fancy superachromatic lenses or what?  (I'm not
> familiar with the longer focal lengths available, except that I heard that
> some were truly superachromatic, i.e., fully corrected at all wavelengths.)

It says so in the "photo information" part.

The Superachromat advantage is definitely lost when using the lens handheld.
Since i know you won't believe it when i say that, here's what Zeiss' very
own Kornelius J. Fleischer has to say about it:


"Utilizing the image quality potential of this lens fully requires adequate
technique: high resolution films like Velvia and Portra 160 VC, very sturdy
tripod and mirror-lock-up, meticulous focussing, maybe even focus bracketing
to compensate for film flatness errors, thermal expansion, alignment
deviations of focussing screen, mirror, and the like."

;-)


Date: Sun, 26 May 2002
From: "Mxsmanic" mxsmanic@hotmail.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Does the 1/focal length rule hold for MF?

"fotocord" fotocord@yahoo.com a ,crit...
> As the focal length is longer at the same
> distance from the subject, any motion
> will be magnified. This got me to thinking
> about another reason this "formula" doesn't
> work, as if you're closer to the subject, the
> more shake will be noticed.

Not true.  Most camera shake caused by the photographer is rotational: The
camera is moved in rotation about some fixed point in or near the camera
body.  This causes the image on the film to be blurred by a fixed amount
irrespective of subject distance, but partially a function of lens
magnification.  If the camera rotates through one degree, for example, then
the image will show a motion blur covering one degree of the photographed
scene, irrespective of how far away the scene might be.  If a wide-angle
lens was used to take the picture, it has a large angular coverage, and so
the one degree of blur might be unnoticeably small on the finished photo;
but if a telephoto lens is used to take the picture, one degree might cover
a large fraction of the lens' viewing angle, and so the blur will be
obvious.

Thus, camera shake is indeed related to focal length, but not to subject
distance.

In contrast, amera shake coming from other sources may not be just
rotational but also translational.  In this latter type of movement, the
camera does not rotate; it simply slides from one position to another while
keeping the same orientation.  When this type of movement occurs, motion
blur on the final image will correspond to the projection of the
translational offset.  So if the camera moves by one millimetre, everything
in the photographed scene will move by one millimetre, also, as projected
onto the film--but for subjects at anything other than extremely close
distances, a one-millimetre movement will not even register on film, much
less cause blurring.  If you shoot a car 10 metres away with a camera and
the car moves one millimetre, will that blur your image?  Not usually,
unless you are using an extremely long lens.

> Think about what a huge problem camera shake is
> with macro work and you'll understand what I'm saying.

With macro work, translational movement is more important than rotational
movement.  One millimetre of movement in a subject only ten centimeters away
is pretty substantial.  But movement caused by the photographer holding the
camera is usually rotation.  Tripod vibration is usually translation, if the
camera is securely mounted.



From: "David J. Littleboy" davidjl@gol.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Does the 1/focal length rule hold for MF?
Date: Tue, 28 May 2002

"Q.G. de Bakker" qnu@worldonline.nl wrote:
> Mxsmanic wrote:
>
> > Unless you are supporting the camera directly beneath its center of
> gravity
> > and/or you are holding it with extraordinary rigidity (similar to that
> > provided by a sturdy tripod), it will be mostly rotational.
>
> There you go again.
> Why would it be mostly rotational?

Basic physics: it would be hard to make it mostly translational unless the
force applied is directed directly at the center of mass of the system. But
the shutter release on most cameras isn't (except for some Kievs) and the
focal plane shutter is jerking at 90 degrees to axial, and the mirror is
rotating. Most of the forces have a large tangential component.

Maybe "mostly" is an exaggertion here, but there will rarely be no
rotational component.


David J. Littleboy
Tokyo, Japan


From: "Bill D. Casselberry" bcasselb@orednet.org
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Pentax 6X7 / shutter speed
Date: Thu, 30 May 2002


Belle Long wrote:

> What is a good shutter speed to start with for landscape .

        Go buy a 10 lb bag of rice or lentils at the market and stuff
        it into some sort of cloth bag. Snuggle the 6x7 down into it
        and frame up your scene (taking the prism off will let you see
        the whole image - though it will be flipped sideways) until
        everything is all as you like it, lightly but firmly pressing the
        6x7 into the ricebag / use the mirror lockup / wait a second or
        so and then fire the shutter. This way any shutter speed will
        be just fine. Make use of the hyperfocal scale on the lens and
        use a tightish aperture if you want extended depth of field.

        Bill

Bill D. Casselberry ; Photography on the Oregon Coast
http://www.orednet.org/~bcasselb
bcasselb@orednet.org


Date: Wed, 29 May 2002
From: "Victor Bazarov" vbazarov@dnai.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: 1/focal length thread

"Jeffery S. Harrison" karaya@kpunet.net wrote...
> While not a "manic" fan I felt he had asked a reasonable -- probably because
> I've been wondering the same thing :) -- question. One that hasn't been
> answered yet. I first learned about the rule of thumb that says you
> shouldn't use a shutter speed any slower than 1/the focal length of the lens
> you're using back in the seventies when I was learning photography with a
> 35mm camera. I never used medium format until a couple of years ago and
> until that time hadn't realized that many of the things I "knew" didn't work
> exactly the same way when you changed film formats. The question manic asked
> was not whether or not this rule of thumb is a good rule or if hand holding
> was something that should ever be attempted, he asked if it worked the same
> in medium format as it does in 35mm. Since a "normal" lens for my Nikons is
> 50mm (yes I know it's really shorter than that) and a "normal" lens for my
> RZ is 90mm does that mean for my RZ I should use 1/90 sec. for my minimum
> shutter speed or would it really be 1/50 sec. ? Was that rule originally
> stated for 35mm or is it older than that?


Considering that maximum unsharpness contributed by the camera
movements is due to shifts of the film plane relative the optical
axis of the lens created by the rotational part of the movements,
it would be logical to conclude that 1/focal_lenght is just what
it says, for almost any camera.  The idea is that the focal length
represents the distance between the optical centre of the lens and
the film plane when focussed at infinity, and the fuzziness is
basically the product of the angular amplitude of the camera shakes
and the distance between the centre of the rotation and the film,
for a larger format you have larger camera, all linear dimensions
are larger, the frame is larger and so is the blurred edges of
the image.  So, enlarged to the _same_ size print, both 35mm and
medium format negatives will look similarly unsharp if only the
camera shaking because of unsteady hands were considered.  But...
medium format cameras are bulkier (heavier), so are their mirrors
and shutters (on rangefinders).  So, amplitude of the rotational
movements (those that contribute the most to the blur) can be
smaller or larger, it is rather difficult to estimate based only
on those data.
         __                 _
      |<    >|           |<   >|
         ||                 |
         /|                 |\
        / |                 | \
       /  |                 |  \
      /   |           |-----+---+---| 35mm frame
     /    |                 |   |
    /     |                  Blur
   /      |
|-+-------+-----------| 6x6 frame
  |       |
    Blur

With angular amplitudes the same in both cases blur would be
proportional to the focal length and (if both lenses "normal")
to the size of the frame.

BTW, the rule I originally heard that for a normal lens on 35mm
1/30 was the marginal to hand-hold the camera, not 1/60...  And
normal would be 50 or 55mm lens, of course...

Does my babbling make any sense?

Victor
--


From contax mailing list:
From: "Jerzy Kolaczynski" jerzykolaczynski@acn.waw.pl
Subject: RE: [Contax] RE: Mirror damping TEST !!!  do this yourself
Date: Tue, 18 Jun 2002 

> With this combination (Aria + 85/2.8), I do'nt see any vibration caused at
> any exposure time. So with the Aria mounted directly on a tripod, the
> vibration problem does not exist.

> Now for the meat: When I put my 300/4 on the tripod with the Aria, problems
> arrive. The mirror causes a lot af vibration at ALL exposure times. Because
> the body is not directly on the tripod, the vibration is probably multiplied.
> Melvin


I've read once an article about problems with using long lenses like 600 mm,
when people finally get them and couldn't use it. The advice was: put one
hand at the end of the lens, because it will stop vibrations! It was here:
http://www.naturephotographers.net/bh0201-1.html

Maybe it will help

Jerzy


From: "Q.G. de Bakker" qnu@worldonline.nl
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: MF gear for landscapes?
Date: Wed, 3 Jul 2002

John Eyles wrote:

> I still believe that at 1/125-sec or above, in 35mm, one losses NO
> sharpness fom hand-holding (well ok, one with reasonably good hand-
> holding technique), because of the blur being less than film resolving
> power.   Can anyone comment on my theoretical argument that for a
> frame size twice as large that twice the shutter speed (i.e. 1/250)
> is equally amenable to hand-holding ?

Yes.
I'm sure you can't handhold a 35 mm format camera at 1/125 sec. or even
above and get good results using a 1000 mm lens. ;-)
All talk about shutterspeed and blur being less than resolving power is
quite meaningless unless related to focal length, i.e. magnification (of
both image and movements) on film.

And what about the physical size of things? A 28 mm lens for 35 mm format is
quite small and, but a similar lens for 6x6 is quite something else. Another
factor to consider. Weight, or mass rather, can be a help too. 

Yet another factor to consider is the ergonomics of the equipment.

And frame size too is meaningless considered alone: if you can handhold a 35
mm lens on a half-frame (18x24 mm) 35 mm camera at 1/125 and get good
results you can handhold a 35 mm lens on a full-frame 35 mm camera and get
good results at the same speed.
By the same token (forgetting about the physical size and weight of the
equipment for a moment) if you can handhold a 50 mm lens at 1/125 using a 35
mm camera, there is no reason why you can't handhold a 50 mm lens at 1/125
using a 6x9 camera.
Its image magnification on film, i.e. angles of view, that matter.

But you do know all that. ;-)

> Or can someone with more MF experience that me confirm or deny that they
> have witnessed an increase in sharpness by using a tripod at speeds of
> 1/250 or above ?            

I can confirm that, yes.

It's not too difficult to get bad shots handheld even at very short speeds.
On the contrary.

Whether or not a handheld shot comes out right depends on too many factors
(and that's no different whatever format you're using): sleep well the night
before?; just ran a marathon before trying to pinch a shot using you're
heavy telelens handheld?; windy out today?; etc.
A tripod is the personification of calm and sturdiness. Seldom fails.
  



From: jge@cs.unc.edu (John Eyles)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: MF gear for landscapes?
Date: 2 Jul 2002

Actually, for "more modern gear" in 6x9 there are very few choices
I think you'll find.   I like the Fuji 6x9 range-finders.  About
$1400 new from B&H.;  I bought mine used, in excellent condition, for
about $800 from KEH.  Robert White (www.robertwhite.co.uk) seems to
have new ones for 600-700 UK pounds, which is a hell of a lot less
than $1400, assuming shipping and various duties and taxes aren't
too much; never ordered from them, so I can't say.

One respondent said "tripod mounted"; I personally am not one of those
who believe you must always tripod-mount a medium-format camera.  I've
reasoned that if one can hand-hold a given shutter speed in 35mm, one
should be able to hand-hold double that speed in 6x9.  To say "I can
hand-hold 1/125-sec", you mean that the blur on the film plane induced
by the camera movement is less than the resolution of the film.  Since
the 6x9 film is about 2-2.5X the size of 35mm in linear dimension, and
if camera shake is mostly a rotation, then the same amount of camera
shake in 6x9 will correspond to 2-2.5X as much blur on the film plane
(in absolute dimension). Assuming the same emulsion, we need the
absolute blur to be the SAME to say "I can hand-hold this speed".   So
the shutter-speed must be 2-2.5X faster.    Hence, I assert I can
hand-hold 1/250-sec in 6x9 (since I can easily hand-hold 1/125-sec in
35mm) and STILL TAKE ADVANTAGE of the increased resolution of the 6x9
format.  Now, if camera shake is mostly translational movement (as
opposed to rotation), the analysis is different, but I still don't
believe you'd have to de-rate your hand-holdable speed by more than 2.
Also, MF cameras are heavier, which helps you hand-hold steadily until
the point the camera is so heavy you have trouble holding it; the Fuji
6x9's are certainly not that heavy (about 3lb).

Now, of course, since MF depth-of-fields are so awful, typically one needs
higher f-stops and slower shutter speeds, which of course will tend to
require a tripod.  BUT, for doing landscape work, frequently (but not always)
everything will be effectively at infinity and you can open the lens all
the way.  Bottom line is that for 100-speed film shooting in daylight for
typical landscape scenes, 1/250 is a usable shutter-speed and is hand-
holdable.  I realize this is a limited scenario and I would never assert
you don't need a tripod; I'm simply doubting the conventional wisdom
that ALL shots must be tripod-mounted.

Does this make any sense at all ?

John

>> I am looking at getting into MF for doing some landscape and  limited
>> portrait work.
>> I have experimented some with an old folding camera and fell in love with
>> the huge 6x9 frames.
>>
>> Now I would like to upgrade to a more modern gear and there are so many
>> choices that I am not sure were to start.  



Date: Thu, 27 Jun 2002 
From: Craig Roberts crgrbrts@netzero.net
To: rollei@mejac.palo-alto.ca.us
Subject: [Rollei] Steady cam hint, medical tip and new book review

Hey y'all --

Here's another steady focusing tip: loop your camera strap around your hands
to taughten it on the back of your neck. I think this trick is illustrated
in the old Rolleiflex users manuals.  Combine this with the Douglas Cooper /
Dr. Heering focusing hood-forehead crunch and you'll become Manfrotto Man!

And here's a related medical tip. If you've found your shots to be shakier
than they used to be, it just might be a symptom of a medical condition. Two
years ago I thought I'd have to give up photography altogether because of
pronounced hand tremors.  When I lamented about this to my physican, he
ordered a thyroid workup. Sure enough, I had a mild hyperthyroid condition.
I responded quickly and well to treatment and today I can easily hand-hold
shots that would've certainly required a tripod before.

And thanks to Richard Knoppow, by the way, for his informative answer to
Jorge's question about 1/500 sec. settings on older shutters. I'd wondered
about this myself.

One last thing -- especially for fellow Washingtonians.  Go to
http://www.kousoulas.com/Portrait.html and check out George Kousoulas' new
book of medium format black and white photos of DC.  I saw the volume today
at Olssen's bookstore at Metro Center and it's extraordinary.  Take your
Rollei and a roll of Ilford HP5 Plus with you when you go downtown because
after browsing through George's book, I guarantee you'll be inspired. 

Craig
Washington, DC



Date: Thu, 27 Jun 2002 
From: Richard Knoppow dickburk@ix.netcom.com
To: rollei@mejac.palo-alto.ca.us
Subject: Re: [Rollei] Re: Focusing at Waist Level

you wrote:
>Well, I went and found my own odd -- quite unexpected -- answer to the
>question I posted:  how properly to focus a Rolleiflex TLR.  I dug up Dr.
>Walther Heering's THE ROLLEI BOOK (which I never much look at, because it's
>not all that Rollei-specific), and *he* suggests not only getting your eye
>as close as possible to the magnifier, but also "to press the forehead at
>the same time against the upper, wide rim of the hood."
>
>This is something I'd never even considered.

  Forhead bracing is a useful trick. The Stereo Realist camera was built
"upsidedown" with the finder at the bottom because it was intended to be
used hand held with the body of the camera pressed against the forhead. 

This trick can be used with many 35mm cameras although the controls can be
inconvenient. Try it just to see how steady the camera becomes.

----
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com 



Date: Thu, 27 Jun 2002 
From: Phil Stiles stiles@metrocast.net
To: rollei@mejac.palo-alto.ca.us
Subject: Re: [Rollei] Re: Focusing at Waist Level

Doug, just as there's more than one way to skin a cat, there are many
ways to hold a Rollei. One of my favorites is the stealth method: camera
on the neck strap is rotated about 110 degrees to the left, and the left
arm is moved slightly out at the elbow.  You are now shooting toward the
rear, from under your arm pit.  I've gotten some great candid effects,
most people have no idea you are taking pictures of them! (PS It's all
done with mirrors, no smoke required.)  Naturally, this doesn't have a
lot of application in the bush, shooting scenics.

Regards,
Phil Stiles NH USA



Date: Thu, 27 Jun 2002 
From: bigler@ens2m.fr
To: rollei@mejac.palo-alto.ca.us
Subject: Re: [Rollei] Focusing at Waist Level with magnifier

 From Douglas Cooper:

> ....I read a post recently -- I forget where -- which seemed to
> indicate that some people flip open the magnifier at waist level,
> and never bring the camera up to their eye. I'm going to go out
> tomorrow to experiment... but is this possible?

Optically speaking, the magnifiers send the output optical image of
the ground glass quite far away "under" the camera. If the magnifier
lens was placed so that the ground glass is exaclty locatd in its
focal plane, the image would be sent to infinity, so you could see it
sharp from anywhere provided that you can see sharp at infinity, this
is another stroy. Usually the image is not sent to infinity but 
closer, say, q between 0.5 metre (~1.5 feet) and 1 metre (~3 feet).

The problem when looking through the magnifier lens, very far from it,
is that you loose the field of view. In other words the portion of
image that you can see at the same time is very small even if this
portion of image is quite sharp.

People like me wearing eye glasses have already hard times seing the
whole 56x56mm R-TLR image at once. A single lens magnifier is very far
from a moder high-eyepoint eyepiece !!


> I'm still trying to decide whether I like the split image or not, so I'm
> spending some time thinking about focusing.  I read calculations which
> indicate that a well-designed split image, using a normal lens -- eg. a
> Rollei -- should have accuracy equal to a good rangefinder.

The ability of the human eye to detect mis-aligned line patterns is
incredible. If you consider that the angular resolution of the eye for
two nearby dots is between 1 minute and 2 minutes of arc, in fact you
can align a "broken straight line" within a small fraction of this
resolving power. The same applies to a rangefinder system, except that
you usually judge the propoer setting on a "double image" pattern in a
rangefinder, and not a simple "broken straight line" which makes, this
is a personal guess, the split-image "crossed prisms" device at least
as accurate as a RF.

--
Emmanuel BIGLER
bigler@ens2m.fr




Date: Thu, 27 Jun 2002 
From: Richard Knoppow dickburk@ix.netcom.com
To: rollei@mejac.palo-alto.ca.us
Subject: Re: [Rollei] Re: Focusing at Waist Level

you wrote:
>Well, I went and found my own odd -- quite unexpected -- answer to the
>question I posted:  how properly to focus a Rolleiflex TLR.  I dug up Dr.
>Walther Heering's THE ROLLEI BOOK (which I never much look at, because it's
>not all that Rollei-specific), and *he* suggests not only getting your eye
>as close as possible to the magnifier, but also "to press the forehead at
>the same time against the upper, wide rim of the hood."
>
>This is something I'd never even considered.

  Forhead bracing is a useful trick. The Stereo Realist camera was built
"upsidedown" with the finder at the bottom because it was intended to be
used hand held with the body of the camera pressed against the forhead.
This trick can be used with many 35mm cameras although the controls can be
inconvenient. Try it just to see how steady the camera becomes.

----
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com



Date: Fri, 28 Jun 2002 
From: Eric Goldstein egoldste@earthlink.net
To: rollei@mejac.palo-alto.ca.us
Subject: [Rollei] Re: Focusing at Waist Level

"Richard Knoppow" wrote:

> Forhead bracing is a useful trick. The Stereo Realist camera was built
> "upsidedown" with the finder at the bottom because it was intended to be
> used hand held with the body of the camera pressed against the forhead.
> This trick can be used with many 35mm cameras although the controls can be
> inconvenient. Try it just to see how steady the camera becomes.

Seton Rochwhite would be honored you remembered his best design...

Another good bracing maneuver... Step on your camera strap and pull up while
shooting...  

Eric Goldstein 



Date: Fri, 28 Jun 2002 
From: Richard Knoppow dickburk@ix.netcom.com
To: rollei@mejac.palo-alto.ca.us
Subject: Re: [Rollei] Focusing at Waist Level with Magnifier

you wrote:
>
>> Usually the image is not sent to infinity but
>> closer, say, q between 0.5 metre (~1.5 feet) and 1 metre (~3 feet).
>
>
>Does this mean that you're actually *better* off focusing at waist level,
>than closer?  It doesn't seem to cause eye strain to put your eye right up
>against the magnifier.   Or do you get a proper image from one inch to one
>metre?     

  Its common for finders to present an image at a virtual distance of
around one meter. The idea is that this is a comfortable distance for most
people and a good compromise for normal vs: near sighted people.

  Many cameras, including the Rolleis, have a provision for changing the
lens to match the eye of the user. Since we are discussing cameras which
have not been made for many years the replacement lenses may not be easy to
get but some are avialable. If you are lucky you can find one to match your
vision.

 Both the top magnifier (and back magnifier on Rolleiflexes) are meant to
be used with your eye near them. One doesn't usually use a magnifying glass
at a distance, the same is true of the magnifiers in the cameras.
----
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com 



Date: Thu, 27 Jun 2002 
From: Phil Stiles stiles@metrocast.net
To: rollei@mejac.palo-alto.ca.us
Subject: Re: [Rollei] Re: Focusing at Waist Level

Doug, just as there's more than one way to skin a cat, there are many
ways to hold a Rollei. One of my favorites is the stealth method: camera
on the neck strap is rotated about 110 degrees to the left, and the left
arm is moved slightly out at the elbow.  You are now shooting toward the
rear, from under your arm pit.  I've gotten some great candid effects,
most people have no idea you are taking pictures of them! (PS It's all
done with mirrors, no smoke required.)  Naturally, this doesn't have a
lot of application in the bush, shooting scenics.

Regards,
Phil Stiles NH USA 


Date: Thu, 27 Jun 2002 
From: Douglas Anthony Cooper douglas@dysmedia.com
To: rollei@mejac.palo-alto.ca.us
Subject: [Rollei] Re: Focusing at Waist Level

Well, I went and found my own odd -- quite unexpected -- answer to the
question I posted:  how properly to focus a Rolleiflex TLR.  I dug up Dr.
Walther Heering's THE ROLLEI BOOK (which I never much look at, because it's
not all that Rollei-specific), and *he* suggests not only getting your eye
as close as possible to the magnifier, but also "to press the forehead at
the same time against the upper, wide rim of the hood."

This is something I'd never even considered.

So... today I went out and investigated both alien methods.  First I tried
focusing through the magnifier, with the camera at waist-level.  I was
surprised to discover that this makes the center split/microprism actually
quite useful:  it fills the magnifier, and makes a perfect bullseye. 
Composing is still a bit easier with the camera closer to your face, if only
to block out light from above, but it's still possible to use it at waist
level.  Hm.

Then I tried Dr. Heering's method.  This, in fact, proves a subtle
revelation.  Split screens are particularly difficult with the TLR, because
aiming the camera steadily is less intuitive (when the camera moves, the
image movement is not in the direction you would immediately expect), and
because when your eye drifts off center, the focus shifts.  Here's where Dr.
Heering's technique truly improves things:  with a hand at either side and
your forehead pressing in from on top, you have tripod-like steadiness, and
-- even more important -- the camera is suddenly fixed in relation to your
head, so your eye stays centered on the split image.

Now quite possibly all of you discovered this forty years ago, but it's one
of those tiny epiphanies that will probably alter my technique for good. 

Douglas Cooper
http://www.dysmedia.com


From: davesenesac@msn.com (DaveSenesac)
Newsgroups: rec.photo.equipment.medium-format
Subject: Benbo extended center column dampening trick
Date: 23 Jun 2002 


I have been trying to figure out how to dampen vibrations on my Benbo
Trekker when the center column is extended up in order to increase
camera height.  Maybe the following will help some others out with the
same problem.

The 5.5lb Trekker at the non extended center column height is
relatively stable  when balanced correctly but quickly becomes like a
ringing tuning fork as it is extended off the base position.  It is
basically fit for only 35mm sized cameras  which is what I originally
used it with.  But I have been using it the last two plus years with
my Pentax 6x7 which is even worse than it sounds because 80% of my
shots are with the weighty 55-100mm zoom.  With medium format it is
more important to get higher off the ground because loss of near depth
of field due to longer focal lengths.  Of course I use mirror lock up,
timer, shutter cable release, and the weight of 15 plus pounds of
other gear in two packs draped over the tripod and or pentaprism to
deaden things as much as possible but until I brainstormed this today
nothing I did would deaden that heavy load at the end of the extended
center column and I avoided using it as much as possible.   Obviously
weighting the camera at the top has been nonsense.

So what I did today was take a 6 ounce piece of 58 inch long
rectangular shaped 0.5"x0.7" wood molding from the local Home Depot
and simply stick one end of the wood at the ground and the other end
at an opposing angle up to the base of the ball head to camera
interface and suddenly forward vibrations decreased to hardly
anything.  I am still weighting the tripod down at the vertex of the
legs, and the wood tension is such against the camera body that it
flexes the center column slightly upward to give it some taughtness.
I'm having a carpenter brother build a custom 8 inch long rectangular
sleeve so I can cut the 58 inch long piece of wood into two field
manageable 29 inch lengths and then quickly assemble them together
into the longer coherent length.  The wood doesn't help side to side
vibrations since that is perpendicular to the plane of the wood but
most of the problem has always been in the forward up and down
dimension.  I will probably customize the wood end that goes into the
ground with some hard rubber pointy spike.

Yesterday I paid another visit to the local pro photo shop and played
with the latest CF models.  As such for the 6x7 I STILL plan to buy
the expensive G1329 but there are many situations out in the field
when the Benbo gets a shot which nothing else can.  And I won't be
getting any more Benbo's / UniLoc's unless they come up with a lighter
carbon fibre version because the standard ones like the #1 which are
the only ones fit for heavier cameras are just too heavy to lug into
the wilderness.  -dave


From: Keith Whaley keith_w@dslextreme.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Handheld speeds are exaggerated!
Date: Mon, 19 Aug 2002


Slightly different breathing technique for better body and finger control...
Moderately deep intake, let almost all of it out, then after a slight
pause, inhale about 1/2 a breath and don't breathe.
You'll have 10 seconds or so with minimum heartbeats and little urge
for taking a new breath.
If you'll practice it, you'll get the proper rhythm and be able to
press the shutter within that time frame.

keith whaley
former pistol instructor



From: "Sherman" sherman@dunnam.net
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Medium format on ships?
Date: Wed, 25 Sep 2002

...


There are some high density foams, specifically "thermal foam" used in some
pillows and mattresses that are outstanding vibration absorbers.  One piece
of this under each tripod leg might eliminate most vibration from the
engines.  The stuff is expensive and not widely available but only a small
amount would be needed.

I haven't any personal experience with this so take it with a grain of salt.
I got this tip from a photographer who was shooting on the roof of a
building right next to the air handling units.  The roof was vibrating
enough to be felt easily through the soles of my sneakers and his claim was
that the foam eliminated the vibration allowing him to use 1/30 of a second.

Sherman



From: Bill Tuthill ca_creekin@yahoo.com
Newsgroups: rec.photo.equipment.35mm
Subject: Sigma rebadging Nikon 80-400 VR?
Date: Fri, 04 Oct 2002


TP was "half serious" about this, and we've had some philosophical debates
about whether he was half serious, or half joking.

Sigma's website now shows their lens to be much heavier and closer focusing
than the Nikon, and shorter.  But they do take the same filter size!

Perhaps Sigma bought the VR stuff, grabbed some optics from one of their
other lenses, and added metal to give the lens a higher-quality feel.

        focal length & speed    wgt     len     cost    close   filter  P_zone
Nikon   80-400/4.5-5.6 VR       1304g   264mm   $1700   230cm   =F877   3.03
Sigma   80-400/4.5-5.6 IS/VR    1650g   192mm   $???    180cm   =F877   ?
Tokina  80-400/4.5-5.6 ATX      960g    136mm   $549    250cm   =F872   2.39


From: Lisa Horton Lisa@lisahorton.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Technique to stabilize a flimsy tripod
Date: Mon, 21 Oct 2002


Put a loop of light cord/rope around the top of the tripod, just above
the "shoulders" of the legs.  Use a clip or common cheap carabiner to
attach your bags shoulder strap to the rope loop.

When you don't want to be in the picture, you can also use another
length of rope and step on the bottom, as you mentioned.

Lisa

FNU Brawijaya wrote:
>
> I have a question about stabilizing a flimsy tripod. I have Velbon
> MAXi-343E and like it a lot. It can handle vertical shooting using
> 70-300mm lens. However, I am just thinking to do it better. I saw an
> article in Popular Photography about Gitzo tripod that has a hook under
> its center column. We can add weight using a bag or whatever attached to
> the hook in order stabilize the whole setup.
>
> I am wondering maybe somebody out there has experience in attaching a
> hook in the center column of Velbon MAXi or other tipod. I also have an
> idea to put a string and straighten the string using our foot to give
> more stabilization. However, I can not pose myself with my family. I
> will appreciate any thoughts about it.


From: Lisa Horton Lisa@lisahorton.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Technique to stabilize a flimsy tripod
Date: Mon, 21 Oct 2002


I forgot to mention... about that carabiner.  What's nice about using
a carabiner is that you can just leave it on the shoulder strap all
the time.  When you're not using it, the carabiner just slides to the
bottom of the shoulder strap, out of the way.  This works well for
tripods that have a ring or other provision for attaching a weight.

Good thing carabiners come in black now:)

Lisa



From: Leonard Evens len@math.northwestern.edu
Newsgroups: rec.photo.equipment.large-format
Subject: Effects of movement on image quality?
Date: Sun, 27 Oct 2002

I'm interested in taking pictures of trees and other plants where
subject movement is likely to affect the sharpness of the image.  The
math seems fairly simple.  The amount the subject moves in time T is
v*T where v is the speed of the subject.  This gets reduced to M*v*T in
the image plane where M is the scale of reproduction.  If one wants this
less than the diameter c of the circle of confusion in the image plane,
one needs

T < c/(v*M)

For distant objects, one can take  M = f/s where f is the focal length
and s is the subject distance. Assume one were photographing leaves at
10 meters  with a 150 mm lens, and one chose a circle of confusion of
diameter 0.1 mm.  Suppose the leaves were moving at 1/3 m/sec. Then one
obtains that
T < 0.1/((1000/3)*(150/10000)) =  1/50 th of a second


According to this, one can tolerate movement more easily if  M  is
smaller, i.e, if either the nearest moving subject is relatively far
away and/or if the lens focal length is smaller. (But, when one uses a
wide angle lens, one tends to be closer to the nearest part of the
subject, so perhaps these factors cancel out.)  Of course, the smaller
v  is, the better off one is.

But there are several questions about such assumptions which may affect
how this works in practice.  First, is it really enough that the
movement be included in the circle of confusion chosen for depth of
field considerations, or should it be even smaller?   Second, what are
reasonable assumptions about subject speed in various wind conditions?

I would appreciate advice about this.  Heretefore, I used a medium
format camera with limited movements, so I could usually get adequate
depth of field while still shooting at 1/60 or sometimes faster.  With 4
x 5, I find I usually have to stop down to at least f/16 and usually
more.  I am using mainly Portra NC 160, and I find I often have to shoot
at 1/30 and sometimes slower.  I try to work when there is little wind,
but even a small breeze can produce leaf movement, and it is often not
uniform across the subject.  Should I consider using a faster film?  How
much will that cost me in image quality?

--
Leonard Evens      len@math.northwestern.edu  
Dept. of Mathematics, Northwestern Univ., Evanston, IL 60208



From: "Roger N. Clark" rnclark@qwest.net
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Effects of movement on image quality?
Date: Sun, 27 Oct 2002


Leonard:
Wow, shooting at 1/30 second!  Its been rare that I've ever
gotten that fast.  I usually image at f/48 or so and with Velvia
at ISO 50, exposures are usualy 1 or 2 seconds in my experience.

In many cases, wind ebbs and flows, so if you wait, you can usually
find a lull to get your exposure.  In a large scene, there may be
some leaves, flowers, etc which may be blurry, but if your
main subject is still and in focus, it diverts attention
from blurred objects.  Example:

http://www.clarkvision.com/galleries/gallery.landscape-1/web/c072099_L4_01a2-600
b.html

The main flower is in sharp focus.  Some of the flowers
in the middle distance are blurred due to wind (the web image
is too small to show this), but viewers of my 30x40 inch
lightjet prints have never once mentioned the blurry
flowers.  (I did wait about 5 hours for the right
conditions for this image, but the wait was mainly for
cloud shadows; every 10 to 20 minutes it got still enough
for an image, about 2 seconds at f/64.)

Roger Clark
Photo home page:  http://www.clarkvision.com
...


From: bg174@FreeNet.Carleton.CA (Michael Gudzinowicz)
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Effects of movement on image quality?
Date: 28 Oct 2002

Leonard Evens len@math.northwestern.edu wrote:
> I'm interested in taking pictures of trees and other plants where
> subject movement is likely to affect the sharpness of the image.
> The math seems fairly simple.  The amount the subject moves in
> time T is v*T where v is the speed of the subject.  This gets
> reduced to M*v*T in the image plane where M is the scale of
> reproduction.  If one wants this less than the diameter c of the
> circle of confusion in the image plane, one needs
>
> T < c/(v*M)
>
> For distant objects, one can take  M = f/s where f is the focal
> length and s is the subject distance. Assume one were
> photographing leaves at 10 meters  with a 150 mm lens, and one
> chose a circle of confusion of diameter 0.1 mm.  Suppose the
> leaves were moving at 1/3 m/sec. Then one obtains that
>
> T < 0.1/((1000/3)*(150/10000)) =  1/50 th of a second
>
> According to this, one can tolerate movement more easily if  M
> is smaller, i.e, if either the nearest moving subject is
> relatively far away and/or if the lens focal length is smaller.
> (But, when one uses a wide angle lens, one tends to be closer to
> the nearest part of the subject, so perhaps these factors cancel
> out.)  Of course, the smaller v  is, the better off one is.
>
> But there are several questions about such assumptions which may
> affect how this works in practice.  First, is it really enough
> that the movement be included in the circle of confusion chosen
> for depth of field considerations, or should it be even smaller?
> Second, what are reasonable assumptions about subject speed in
> various wind conditions?
>
> I would appreciate advice about this.  Heretefore, I used a
> medium format camera with limited movements, so I could usually
> get adequate depth of field while still shooting at 1/60 or
> sometimes faster.  With 4 x 5, I find I usually have to stop down
> to at least f/16 and usually more.  I am using mainly Portra NC
> 160, and I find I often have to shoot at 1/30 and sometimes
> slower.  I try to work when there is little wind, but even a
> small breeze can produce leaf movement, and it is often not
> uniform across the subject.  Should I consider using a faster
> film?  How much will that cost me in image quality?

You used 0.1 mm for the coc, which is approximately 10 lines per
mm. From medium format, the maximum sharp enlargment would be
2.5 X, or roughly a 6" x 8" print. If the coc of 0.1 reflects your
intention to make small enlargements, then use the fastest color
MF films available (EI 400 & 800). At 2.5 X grain and sharpness
are not a problem.

Circles of confusion are additive, so if motion contributes 0.1
mm to the coc, contributions from defocus and to a lesser degree,
diffraction, can not be tolerated. In other words, everything in
the scene closer than the plane of sharp focus will have a coc
greater than 0.1, and therefore will appear less sharp or out of
focus. Depth of field is nil in front of the plane of focus since
magnification of motion is greater than at plane of focus. Distant
objects may appear sharper, since the contribution from motion is
less at the reduced magnifications.

If possible, use the highest shutter speed which gives adequate
depth of field, and expose when motion in the foreground is
minimal.

Another alternative for small prints is to use a 35 mm camera.
The effect of motion in the print will be similar to MF at the
same shutter speed. However, for the same depth of field in a
same size print, one may open the aperture by two stops and
use a speed 4 X greater to reduce motion.




From: Leonard Evens len@math.northwestern.edu
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Effects of movement on image quality?
Date: Mon, 28 Oct 2002


Michael Gudzinowicz wrote:

Thanks for the thoughtful suggestions.
>
>
> You used 0.1 mm for the coc, which is approximately 10 lines per
> mm.

That is in the film plane.  For a 4 x 5 negative, which is what I was
talking about, that amounts to about 5 lp/mm in an 8 x 10 print, viewed
at 10-12 inches, or less in a larger print viewed further away.

> From medium format, the maximum sharp enlargment would be
> 2.5 X, or roughly a 6" x 8" print.

For medium format I generally use a roll film holder with a 6 x 7
format.  Enlarging to 8 x 10 requires a magnification of about 3.6.
Taking 5 lp/mm in the print as a standard, that requires about 18 lp/mm
in the negative, or a coc of diamter about .055 mm.  That is about what
I use for medium format calculations.


> If the coc of 0.1 reflects your
> intention to make small enlargements, then use the fastest color
> MF films available (EI 400 & 800). At 2.5 X grain and sharpness
> are not a problem.
>
> Circles of confusion are additive, so if motion contributes 0.1
> mm to the coc, contributions from defocus and to a lesser degree,
> diffraction, can not be tolerated.

That was what I was trying to understand.  I've seen different
recommendations about how to combine circles of confusion.  One is to
add the diameters as you suggest.  Another is to take the square root of
the sum of the squares.  But perhaps when combining a blur circle from
being out of focus with a "streak" from subject movement, adding is more
appropriate.  After looking at your comments and trying to visualize
what happens to image points and the corresponding confusion disks in
the film plane, I think you are right.

> In other words, everything in
> the scene closer than the plane of sharp focus will have a coc
> greater than 0.1, and therefore will appear less sharp or out of
> focus. Depth of field is nil in front of the plane of focus since
> magnification of motion is greater than at plane of focus. Distant
> objects may appear sharper, since the contribution from motion is
> less at the reduced magnifications.
>
> If possible, use the highest shutter speed which gives adequate
> depth of field, and expose when motion in the foreground is
> minimal.

Right.

>
> Another alternative for small prints is to use a 35 mm camera.
> The effect of motion in the print will be similar to MF at the
> same shutter speed. However, for the same depth of field in a
> same size print, one may open the aperture by two stops and
> use a speed 4 X greater to reduce motion.

I have come to that conclusion myself.  Maybe that is one reason why
most garden photography is done with 35 mm SLRs.  But, as you say, that
might limit the size of the prints one might make a bit.


--
Leonard Evens      len@math.northwestern.edu


Date: Tue, 29 Oct 2002
From: Leonard Evens len@math.northwestern.edu
Newsgroups: rec.photo.equipment.large-format
Subject: Re: Effects of movement on image quality?


Roger N. Clark wrote:
> Leonard Evens wrote:
>
>
>>I recently tried to take a picture of back-lit flame grass at the
>>Chicago Botanic Garden.  I was on a narrow path and the nearest part of
>>the subject was about a meter away and I wanted as much in focus going
>>back from that as possible.  This may be a picture that one can only
>>take with a 35 mm camera and a wide angle lens using a speed of 1/125 or
>>higher.
>
>
> Leonard:
> I think if you work out the math, you will get the same
> blur regardless of format if normalized to the same
> total field of view.  What I mean, is given say an
> 8x10 enlargement, each covering the same apparent
> field of view, the 35mm and 4x5 will show the same
> blur on the print if done at the same exposure.
> blur on the print if done at the same exposure.

I'm not sure what you mean.  The "streak" from a point due to motion
will be the same.  But with the same angle of view with a 35 mm camera,
you get more depth of field at the same f-number, so that allows faster
shutter speeds.  Of course, with 35 mm, you are also limited more by
diffraction because of the need to enlarge more, but shooting at f/11 or
perhaps even f/16 should be manageable.   For a standard 8 x 10 final
print viewed at 10 inches or a larger print viewed proportionately
further away, I calculate the following hyperfocal distances, based on a
value of 0.022 mm for the diameter of the circle of confusion in the print.
4 x 5, 90 mm lens, f/16, enlarged 2.12 times:  48.8 meters
35 mm, 22 mm lens, f/16, enlarged 8.47 times:  11.6 meters
To get the same depth of field with 4 x 5 as with 35 mm with the same
angle of view, one would have to stop down enough to multiply the
f-number by over 4, or more than two stops.
Let me explain a bit about the numbers.  For the purpose of comparison,
I consider the 35 mm format to be 24 x 30 with 3 mm on either side of
the long dimension as room for "shifts".  I take the long dimension for
4 x 5 to be 120 mm.  254/120 = 2.12 and 254/30 = 8.47.  The relative
enlargement is 8.47/2.12 = 4 (very close). 90/4 = 22.5.  The result
would be the same for any pair of focal lengths in the two formats with
the same fields of view.  35 mm has a more than two stop advantage.)

Of course there might conceivably be a difference between how subject
movement affects the image for a leaf shutter and a focal plane shutter.

> However, because you can do tilts with a view camera,
> you should be able to use a wider aperture and win
> with the view camera.  Of course, with a tilt
> lens on the 35mm, it should again equalize the
> formats.

Certainly the view camera has the advantage in that respect.  Even with
a tilt lens, the 35 mm camera won't give the full advantages the view
camera has in choosing the plane of focus.  And one would have to have a
  choice of tilt lenses in different focal lengths.  Unfortunately, many
scenes have two much vertical extent in the near part of the subject for
it to be possible to make much use of lens tilt.  In particular, for the
flame grass scene mentioned above, that was the case.

> Roger
--
Leonard Evens      len@math.northwestern.edu


From: "Victor Bazarov" vbazarov@dAnai.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Avoiding shutter/mirror vibration
Date: Wed, 30 Oct 2002


"David" tapeworm@bellatlantic.net wrote...
> [...]
> My test shots had a vertical-line in all the lights, which suggests to me
> that there was some vibration from the shutter/mirror.
> [...]

Sturdier tripod, mirror lock-up.  Sandbags are good at cancelling
longer vibrations (if any), but for some reason I never needed
them after I got Bogen 3021 legs...  And try not to press the
shutter release button yourself.  There are cables for that (you
may not need mirror lock-up with a cable).


Also, remember that the sky is moving, so even if your shutter
speed is "only" a few seconds, any point light source (and stars
are just that), will introduce a line on the film.  For example,
it takes about 2 minutes for the sun (and the moon) to move its
full diameter.  So, 1.2 seconds would blur the moon's edge for
about 1 percent.  Not so noticeable on a bright disk about 1/2 of
a degree across.  But a point light source can make it noticeable
since it travels about 1 angular minute every 4 seconds.  Taken
with 500mm lens (5 degrees diagonal) printed on 8"x12" paper, the
1 angular minute would be about, um, 1.22 mm long.

Victor



From: "Al Denelsbeck" AL@wading-in.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Avoiding shutter/mirror vibration
Date: Wed, 30 Oct 2002 

...(quotes above)

    Small qualifier to this, just to be annoying technical :-).

    The sun and the moon are in the same orbital plane, so they see a
specific amount of motion from the rotation of the earth.

    Stars are a different matter. By orienting on the stars closest to the
line of the earth's axis (for instance, the North Star in the northern
hemisphere), you see very little movement even over long periods. Virtually
none at all for the North Star. But aiming south from the northern
hemisphere, you're looking out over an arc of sky described by your vantage
point on the side of the spinning globe, and star motion becomes more
significant than the 'motion' of the sun or moon.

    So to calculate star motion with any kind of accuracy, you have to take
into account their angular difference from the earth's axis.

    - Al.



From: "Joseph Meehan" sligojoeSPAM2@hotmail.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Avoiding shutter/mirror vibration
Date: Wed, 30 Oct 2002


    You got the idea.  Chances are the mirror lock will do it, that is why
they are on so many cameras.

    The sand bag is not a precise science.  Get a sand proof bag and put a
few pounds in it ( I might suggest about 3-5 lb/ 2k) do some test and see
what works best with your camera.

    Sometimes just hanging the weight from the tripod will work, sometimes
letting the sandbag drape over the camera will help a lot.

    One thing to try.  Tape a mirror on your camera and in a dark room shine
a light one the mirror so it shows on the wall (one of those laser pointers
works great).  Trip the shutter with and without the mirror lock and see
what the spot on the wall does each time.  Since this will also show what
moved after the expose it is not perfect, but it is a good general test.  It
is also a way to play with sandbag placement.

--
Joseph E. Meehan



Newsgroups: rec.photo.equipment.35mm
From: Andrew Koenig ark@research.att.com
Subject: Re: Avoiding shutter/mirror vibration
Date: Wed, 30 Oct 2002 


David> I'm not going to get into weighing down the tripod legs with
David> 50-pound bags, etc.  Just a few suggestions would be
David> appreciated.

1) Use mirror lock-up if you have it.

2) Use a *longer* exposure, so that any short excursions will have
   less of an effect.

3) Eliminate any elastic coupling (i.e. rubber or cork padding)
   between the camera and the tripod.  You want direct metal-to-metal
   contact.  It should be impossible to move the camera even a tiny
   bit without moving the entire tripod.

4) If the tripod has a vertically movable center section, lower it
   all the way.  More generally, retract the tripod legs as much
   as you can.

5) Get a more rigid tripod.

--
Andrew Koenig, ark@research.att.com, http://www.research.att.com/info/ark


From: T. P. t.p@noemailthanks.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Avoiding shutter/mirror vibration
Date: Wed, 30 Oct 2002 



Andrew Koenig ark@research.att.com wrote:
{snip}
>5) Get a more rigid tripod.


That is ALL David needs to do.  If he had bought a good tripod
in the first instance, there would be no need for any of the other
suggestions posted to this thread.

I should point out that, from a structural engineering point of
view, adding weight to an inadequate tripod is virtually guaranteed
to make it *less* stable.


From: "Q.G. de Bakker" qnu@worldonline.nl
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Avoiding shutter/mirror vibration
Date: Thu, 31 Oct 2002


Andrew Koenig wrote:

> Maybe yes, maybe no.  If the camera is not well coupled to the tripod,
> all the tripod rigidity in the world isn't going to help.

And if the camera is 'too well' coupled to the tripod, things get worse.
Cameras produce vibrations. Fixing the camera as tight as possible to a
rigid tripod will allow the entire thing to resonate. Better keep some tiny
amount of play in both camera to tripod fixation and tripod head movement
fixation. That will very effectively dampen those camera induced vibrations,
reducing camera shake.

The opposite is true concerning the 'hang a weighted back from the tripod'
trick. It only works if the extra weight is fixed absolutely rock solid, as
if it were an integral part of the tripod. A swinging weight beneath the
tripod will only help lower the center of gravity, making it a bit harder to
topple the entire thing.




From: nospam@myaddress.com
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Avoiding shutter/mirror vibration
Date: Thu, 31 Oct 2002


I recently conducted an experiment in this space.

I have a rather heavy 100-300mm f4 zoom (1.5 Kg) that misbehaves
(vibration from mirror slap, I'm guessing) at shutter speeds around
1/2 to 1/30 second.  I've observed vibrations on a relatively cheap
tripod and a fairly high end set of legs.

Cleary, the vibrations were less for the much more expensive tripod --
but still observable and obnoxious.  For my purposes and situation,
I've proven to myself that TP's comments don't apply.

I had hoped that a reasonably high end might allow me to make use of
those "danger speeds" on my camera that does not have mirror pre-fire
or MLU -- now I know that isn't possible -- at least in the price
ranges (< $200 for legs) that I'm willing to explore.  So I need to go
faster or slower shutters speds and try to use this "beast" lens with
the body that has mirror pre-fire.

Stuart



From: "Pieter Litchfield" plitch@NOSPAMattglobal.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Avoiding shutter/mirror vibration
Date: Thu, 31 Oct 2002


Never underestimate the value of a solid tripod!!!  I'd argue that it might
be money better spent than "better glass" because it has the ability to
improve the performance of every lens, and even the best lens will produce
poor results without a good one.

 By the way, I too have a Quantaray tripod.  My 500 mm shots of distant
objects were never perfectly in focus.  I was given the use of a 4x5
monorail camera, and bought a big Benbo Model 1 (used on e-bay) for it.
Tried retaking pix of the same distant objects with the same 35mm camera,
film, and lens, but using the Benbo instead of the Quant. tripod.  Huge
difference!  This is not an ad for Benbo, just a suggestion that money spent
on a good sturdy tripod is money well spent.  Suggestion: if money is the
problem, ask around, find which models will work best for you, then shop
e-bay for a used one.  I bet you can get a used quality tripod for about the
same price as a new Ritz special.

...


From: "Al Denelsbeck" AL@wading-in.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Mirror Slap Problem?
Date: Sat, 16 Nov 2002 


    You can test how much mirror slap you have by strapping an inexpensive
laser pointer onto the lens and aiming it down a hallway. Works really well
if you bounce it off of a mirror onto the wall behind the camera, doubling
the length of the beam travel and allowing you to observe it very closely.
Set for a long shutter speed, such as four seconds of better, and see how
much the dot dances.

    Then do nothing with the shutter, but just tap the camera, and see if
you get significant jiggling of the pointer. It could be your tripod mount
isn't secure enough.

    Also, shoot a 1/10 of a second exposure, as well as a ten-second one.
You can do this in a dark room focused on a small flashlight bulb, christmas
bulb, whatever. If the 1/10 of a second expsoure is blurrier than the 10
second one, this would indicate mirror shake. Use a remote release so you
don't shake the camera when pressing the shutter.

    It took me a very long time to discover that my focusing screen had
slipped slightly. At f-stops higher than 5.6 it was almost unnoticeable, but
at 2.8, and especially with macro work, my shots were extremely blurred.
When I finally figured it out, I looked in the mirror box and found it was
not quite locked securely, and was out of place by about half a millimeter.

       As mentioned, wind can cause tripod shake, but generally on longer
exposures. Extending the center column will magnify any vibration, and so
will extending the legs. Keep the tripod as short as possible, and hang a
weight from the bottom of the center column whenever you can.

    Hope this helps. Good luck!

        - Al.
Online photo gallery at www.wading-in.net


From minolta mailing list:
Date: Wed, 20 Nov 2002 
From: "haefr2000" ray_h71@hotmail.com
Subject: Re: Mirror slap

Maybe.  1/125 may not be fast enough even on a tripod to elliminate
camera shake with the lens/combination you're shooting with.  You
need to shoot some fine grain, high accutance slide film without the
telextender, with a STURDY tripod, and with a high shutter speed
(1/300 or faster).  Then repeat the same test with the telextender
with a shutter speed of 1/400 or faster.  If the shots with the
telextender are the only ones that are soft, then superficially the
logical conclusion is that the telextender is crappy.  But keep in
mind that even the finest telextender will result in *some* softening
simply because ANY magnification of the image from the lens will
necessarily magnify ANY performance issues of the lens, itself, too.
If both sets of test shots are soft, you could be looking at
misalignment of the focusing screen such that when you or the AF
focuses, it's wrong for the actual film plane, or the lens (and
perhaps the telextender) is crappy.  With shutter speeds at roughly
the reciprocal of the lens or lens/telextender combination focal
lengths, mirror slap shouldn't be that big an issue.  Or, you could
be overly picky. :)

--- In Minolta@y..., "karenmb60" karenmb@i... wrote:
> As you may remember, I am still using an "almost antique" maxxum 5000
> body. I have much newer lenses, and one of those lenses is a 300mm,
> which I use a 1.4 teleconverter with often. My question: Since I have
> the first, and one of the cheapest maxxum bodies ever made, which
> does have a very loud mirror slap, could this explain some of
> the "less than sharp" pics I am getting from time to time, and I'm
> talking about even when using a tripod and shutter release, or self
> timer. Would mirror slap only effect the image when the shutter speed
> is very slow, or could this also come into play at 1/125 or better?
>
> Thanks,
> Karen


From minolta mailing list:
Date: Wed, 20 Nov 2002 
From: "Kent Gittings" kent@ism.com
Subject: RE: Mirror slap

Depends on how bad it is. MLU or mirror lock up is an option lots of
shooters like to have for that very reason plus the extra noise. Most 35mm
cameras today don't have true MLU, just 2-second prefire on the timer dial
in cases where they have anything at all. Studio shooters like it even on
tripods, so the answer is yes it probably will reduce vibration on a tripod
also but that depends on the weight of the tripod. A really light camera on
a really heavy tripod maybe not, but on the lightweight tripods most use it
probably would help in some cases of longer shutter speeds. Form about 1/250
to the fastest speed it's usually not an issue but below that it can have an
affect.

Kent Gittings



Date: Wed, 22 Jan 2003 
From: "bigmikelf bigmikelf@yahoo.com
To: classic35mmcompacts@yahoogroups.com
Subject: Re: [Classic 35mm Compacts] lens test result...

I also read an interesting thing on
http://www.dantestella.com/technical/rangefinder.html
where they talk about mirror slap affecting camera shake as maybe
being another myth.

Mike


From: Leonard Evens len@math.northwestern.edu
Newsgroups: rec.photo.equipment.large-format
Subject: Re: hand held max shutter time for 4x5"?
Date: Thu, 13 Mar 2003

Andrea wrote:
> hi all,
> after some months of practise with my crown graphic 4x5" with good results,
> i was for the first time getting interested in hand held shooting. i dont
> know if the rangefinder of my camera works. i dont have battery, i dont even
> know how to use it nor how to calibrate it.
>
> before bothering with that, i wanted to try to use the meter on the camera
> bed and the infinity stops. my idea was to adjust the infinity stops in
> order to have a secure reference point for focusing infinity without having
> to look at the ground glass. since i use the camera mostly for landscapes,
> it will probably be enough in 90% of cases.
>
> i was therefore wondering which is the longest shutter time while shooting
> handheld. with 35mm i would say 1/60 or 1/45 sec. with a normal lens. what
> about 4x5"? i have a 135mm lens. i guess it should be shorter since it could
> be easier to see blurriness because of the large format...
>
> Thanks,
> Andrea

As Bob Wheeler points out, a lot depends on what assumptions you make
and how much hand waving you engage in. Let me try some of my own for
what it is worth, which may not be very much.

Suppose you move the camera at velocity v roughly perpendicular to
your line of sight. If you expose for time T, it seems to me, the
result will be a track on the film of size v*T. This won't be visible
in the final image if it lies below some specified threshhold. But that
depends on the degree of enlargement. So the actual problem will be to
keep v*T*E, where E is the degree of enlargement lower. So if you assume
the velocity is the same for the larger as for the smaller camera, then
since E is usually smaller, you ought to be able to get away with using
an even slower speed.

BUT, the assumption that the velocity will be the same for the larger as
for the smaller camera is highly doubtful. The heavier more awkward
camera will usually be harder to keep still. Also, movement is much
more complex than simple linear movement about perpendicular to the lens
axis. There are going to be complex rotational movements which
complicate the analysis signficantly. I

It seems to me the actual effect will depend strongly on the technique
of the photographer. I've used a 6 x 9 technical camera hand held down
to 1/60th and if I had practiced I might have been able to go lower.
Crown Graphics of course were used as press cameras and I'm sure the
news photographers who used them got quite adept at using slow speeds
handheld.

The question of external movement is different. There the trace on the
film depends on the scale of reproduction, which depends indirectly on
the focal length. But as previously noted, the image is enlarged less,
so in total there is no overall effect when you change formats but keep
the same angle of view. However, for smaller formats, you end up using
wider apertures because you can get the same depth of field that way,
even if the final enlarged image has the same size. That means you can
use faster shutter speeds, so there is a real advantage for smaller
formats in controlling external motion with the camera fixed.

--
Leonard Evens len@math.northwestern.edu 


Date: Thu, 13 Mar 2003 
From: Bob Wheeler bwheeler@echip.com
Newsgroups: rec.photo.equipment.large-format
Subject: Re: hand held max shutter time for 4x5"?

From my notes:
"Suppose that vibrations from a lens of focal length f, can
be damped by an exposure time of 1/f. This means that a
point in the subject will image as a circle of confusion, c.
It follows that a 2f lens puts the image twice as far from
the lens, and with the same amount of vibration, the image
will be of size 2c. Hence one can cut the vibrations in half
by using 1/(2f) as the time of exposure to obtain an image
of size c."

Following this logic, if the 35mm lens is a 50mm, and the
4x5 lens 135mm, then the time of exposure should be about
1/3, but the usual circle of confusion for a 4x5 is about 3
times that for a 35mm, hence the factors cancel and the
hand-held time of exposure is the same for the two formats.

Of course this all rests on considerable hand waving and the
assumptions that 1/f for a 35mm camera really does work, and
that one can hand-hold a 4x5 as firmly as a 35.

Andrea wrote:
>
> hi all,
> after some months of practise with my crown graphic 4x5" with good results,
> i was for the first time getting interested in hand held shooting. i dont
> know if the rangefinder of my camera works. i dont have battery, i dont even
> know how to use it nor how to calibrate it.
...
--
Bob Wheeler --- http://www.bobwheeler.com/photo/


From: John john@darkroompro.com
Newsgroups: rec.photo.equipment.35mm,rec.photo.equipment.large-format,rec.photo.equipment.medium-format
Subject: Re: Image size versus resolution and contrast
Date: Thu, 10 Apr 2003 

john@stafford.net (J Stafford) wrote:
> "Bandicoot" wrote:
>
>> 35mm only _begins_ to
>> rival Medium Format if the camera is focussed very critically, and it is
>> stuck on a massive tripod and the mirror locked up, etc. - the MF shooter
>> can snap handheld with autofocus and produce a similar result.
>
>That is so wrong. Handholding a MF is no better than handholding a 35mm
>for the same rules that govern perspective. Think about it. Longer lens,
>and shake is shake regardless of format.

Gotta disagree John. What you say makes sense but in the final print, MF
wins hands down. One of the rags (Pop Photo ?) once published a comparison and
they showed how images enlarged to 8X10 from 35mm showed much more degradation
from hand held usage than did a similar image created from a P67. I can only
assume that the additional mass of the MF camera aided in stability.


Regards

John S. Douglas Photographer & Webmaster
Formulas, Facts and Info on the Photographic Process
http://www.darkroompro.com



From hasselblad mailing list:
From: Jim Brick [jim@brick.org] 
Sent: Wed 5/7/2003
To: hasselblad@kelvin.net 
Subject: RE: [HUG] Superachromat 250 5.6 vs. Summicron-M 90/2


Frank Filippone wrote:
>Jim.. please explain WHY the BTL shutter is so important.... On the
>surface, the shutter is just a timing element. A BTL or a FP shutter should
>have no sharpness issues....
>
>Frank Filippone
>red735i@earthlink.net


Frank,

Tom just answered. Thanks Tom.

The torque required to get a big focal plane shutter moving in one
direction is substantial. Once the first curtain is moving and beginning
the exposure, the second curtain has to start moving. The torque required
to start the second curtain is during the exposure and fine detail can be lost.

Fast FP shutter speeds are immune to the problem because by the time the
camera body starts to move (in an equal and opposite direction), the
exposure is over. The bad speeds are 1/2 -> 1/30. Wide angle lenses are
less effected, the longer the telephoto, the worse the problem. With a long
telephoto (I use a 350 + 2x Mutar quite often for 700mm) and shoot on
Velvia or Provia. Quite often during early morning or late evening light.
And quite often my shutter speed is in the 1/2 - 1/30 range. This is why I
nearly always use the BTL shutter. The BTL shutter is symmetrical and the
forces are circular to the lens. This is virtually vibration free.

Test:

If you have a FP Hasselblad.

Tape a laser pointer to the top of your camera pointing in the same
direction of your lens. Attach your camera to a tripod and your longest
lens to the camera. Point toward a wall around 15'-20' away. Turn on the
laser, pre release the mirror, now via self timer or long cable release,
trip your BTL shutter at 1/8th sec. Watch the laser dot during the exposure.

Now repeat using the FP shutter at 1/8th sec. while watching the dot.

Now try this without using MLU!!!

As Jerry Lee Lewis said, There's a Whole Lot of Shakin' Goin' On.

Jim


From hasselblad mailing list:
From: Tom Christiansen [tomchr@softhome.net] 
Sent: Wed 5/7/2003 
To: hasselblad@kelvin.net 
Subject: RE: [HUG] Superachromat 250 5.6 vs. Summicron-M 90/2

Hi,

>Jim.. please explain WHY the BTL shutter is so important.... On the
>surface, the shutter is just a timing element. A BTL or a FP shutter should
>have no sharpness issues....

Well... Look at the purpose of the shutter. It's a curtain or aperture
which lets light pass through the lens for a predetermined period of time.
As uneven illumination occurs when the shutter is partially open or closed,
the shutter needs to spend as little time between the fully open and closed
states as possible. This means that the shutter is accelerated and
decelerated substantially at the beginning and end of the exposure. Let's
recall Newton's (2nd?) law: Force = Mass * Acceleration. The mass (weight)
of the shutter is not huge - but the acceleration is. This leads to a
significant force when the shutter is opened and closed.

For a BTL shutter, the force is actually a torque (rotational force) as the
shutter leafs are rotated when the shutter opens and closes. This torque
will try to twist the lens and camera around on the tripod head.
Fortunately, the camera/lens/head are quite good at dampening this kind of
torque.

The FP shutters travel either horizontally or vertically. In either case,
the acceleration/deceleration at the beginning/end of the shutter's travel
will apply a force to the camera setup it either the up/down direction or
the left/right direction for vertical and horizontal travel respectively.
Tripods aren't all that great at damping these kind of forces, thus, some
sharpness will be lost.

You can try these postulates rather easy. Stick your camera on a good
tripod. Try twisting the lens by the filter ring. It's rather difficult.
Then try tapping the front of the lens horizontally or vertically. You'll
see the whole setup oscillate.

So the benefits of BTL shutters compared to FP shutters (when it comes to
vibration) are:
1) The shutter is smaller and lighter - thus smaller force for the same
acceleration.
2) BTL shutters apply a torque on the camera. The torque is easy for the
tripod to dampen --> less vibration.

But obviously you'll need to use a good tripod, MLU, cable release, and all
that good stuff to take advantage of this...

Tom



From: Q.G. de Bakker [qnu@tiscali.nl] 
Sent: Mon 6/23/2003
To: hasselblad@kelvin.net 
Subject: Re: [HUG] Re: 503CX Mirror

Henry Posner wrote:

> The longer the overall exposure time, the less influence mirror bounce
will
> have. A decent sandbag on top of the camera's center of gravity will add
> stability. Dangling your camera bag (or your wife's pocketbook) directly
> below the center of gravity will help too.

And the more it dangles, the less it will do anything but lower the center
of gravity, making it harder to topple the tripod, but not much else. ;-).
To help dampen the vibrations that originate in the camera, the added mass
has to be fixed rigidly to the tripod.

Not tightening all the thingies that can be tightened on a tripod
(especially those thingied in/on the head) as tight as possible helps too.
When all moveable fixtures are not "finger torque welded" to the rest of the
tripod, forming one solid resonator instead of a "vibration dampening
device", the very slight play left will dampen the vibrations far better.
Fluid heads are very good for dampening. (And not just when the fluid leaks
out).


From hasselblad mailing list:
From: Henry Posner [henryp@bhphotovideo.com] 
Sent: Mon 6/23/2003
To: hasselblad@kelvin.net
Subject: [HUG] Re: 503CX Mirror

you wrote:
>For the exposures you are describing, I think the image resolution loss
>on the focal plane will likely be far greater due to the unstable tripod
>than any due to camera body vibration caused by the mirror movement.

The longer the overall exposure time, the less influence mirror bounce will
have. A decent sandbag on top of the camera's center of gravity will add
stability. Dangling your camera bag (or your wife's pocketbook) directly
below the center of gravity will help too.
-- -

regards,
Henry Posner
B&H; Photo-Video, and Pro-Audio Inc.
http://www.bhphotovideo.com



From: Jim Hutchison james@jamesphotography.ca
Newsgroups: rec.photo.misc
Subject: Re: Camera shake.
Date: Fri, 04 Jul 2003 


Something no-one's mentioned: it helps tremendously if one of your
hands is cradling the END of the lens. With both hands surrounding
the camera body, movement of the objective lens is greater than
holding the lens at the point where the last element sits. I use
this allot with my 28-300 zoom with much success.


 "tim sewell" tsewell@POQmelbpc.org.au wrote:
>What do others do to minimise camera shake with hand-held shots?
>(A long time ago I was told to control my breathing, but cannot remember the
>details).

jim h


From: "Paul Skelcher" skelch@rcn.com
Newsgroups: rec.photo.misc
Subject: Re: Camera shake.
Date: Fri, 4 Jul 2003

Steve McCurry, National Geographic photographer, Afghan girl cover shot
fame, had a weird way of holding his camera which I saw written up
somewhere a couple years ago.

IIRC the body and lens are cradled in left palm, with left thumb encircling
left side of aperture ring area. Left index finger on shutter, other three
fingers on right side of camera body.
Right palm supporting left hand with right finger and thumb on focus ring.
Whenever I try this I can't help but tilt the camera to the right when
pressing the shutter release, but, whatever works.



From: "Al Denelsbeck" news@wadingin.net
Newsgroups: rec.photo.misc
Subject: Re: Camera shake.
Date: Thu, 03 Jul 2003 

tim sewell tsewell@POQmelbpc.org.au wrote
> What do others do to minimise camera shake with hand-held shots?
> (A long time ago I was told to control my breathing, but cannot remember the
> details).

I tried the breathing trick, never worked for me. Here's a couple of
things that did:

1) This one worked for a rifle as well. I raise the camera aim above the
subject slightly, and allow it to 'settle' into position, gradually slowing
it until it stops on target. It's almost like a very brief countdown. I
think it works because I'm able to synch the shutter release with the pause,
right as my muscles are relaxed and before they start trying to twitch the
camera in another direction.

2) One hand as normal on the shutter release (which is a really crummy
way to support a camera - bad position for the wrist, and a poor set of
muscles to rely on); other hand, palm up, underneath the camera, fingertips
extended out to support the lens. Light touch - don't try to fight the
camera steady, let it rest there. Stroke across the shutter, don't press it.

In some cases, you can gently press the camera against your eye or
forehead, but only if your head is steady. If your head is in a slightly
awkward position, this might makes things worse, since now you're fighting
your neck muscles too.

By the way, if you're using a digicam, especially a camcorder, *don't*
use the flip out LCD screen and try shooting at arm's length! Put the damn
thing up to your eye - keeps your arms bent tightly against your body and
further braces the camera against your head. And it won't make your viewer's
seasick...

- Al.


From: "Ron Andrews" randrew1@rochester.rr.com
Newsgroups: rec.photo.misc
Subject: Re: Camera shake.
Date: Wed, 02 Jul 2003 

"tim sewell" tsewell@POQmelbpc.org.au wrote 
> What do others do to minimise camera shake with hand-held shots?
> (A long time ago I was told to control my breathing, but cannot remember the
> details).

One additional technique that can help when you can't use a monopod,
beanbag, etc. Instead of holding the camera between your thumb and middle
finger and pushing the shutter release with your index finger, try holding
your right hand with your palm towards your face. Support the camera with
the heal of your hand. Push the shutter release with your middle finger.
This is a little awkward, but you are less likely to move the camera as you
push the shutter release.



From: "Victor E. Falkteg" falkteg@brevet.nu
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: minimum shutter speeds
Date: Tue, 19 Aug 2003 

It's impossible to design a formule for this.

Factors that are of importance and not general but individual are:

1. What kind of camera? A rangefinder with a leaf shutter or a mirrow reflex
with a mirrow that slams up? Differnt vibrations for different brands and
types.
2. How heavy is the camera? A heavy camera vibrates less then a light one.
3. How stady are your hands? Higly individual.
4. How much unsharpness do you tolerate? Are you going to make huge
enlargements or just small pictures?

If there is any difference between 35 mm and MF, well, then it could be the
fact that the normal enlargment factor is smaller in MF so you can tolerate
a greater unsharpnes on the negative and still have the same quality at the
paper picture.

My advise is: test your camera with your hands and arms with different
shutter speeds and the make enlargments of different size.You will get a
value you can accept.

Then of cource, if you double the focal lenght then you have to halfen the
shutter speed (very approximately but good enought for daily use).

But you have to make your own test.

Victor E Falkteg

"Neil Smith" neil@SPAMdragpix.com wrote
> I know that with my 35mm camera, my minimum shutter speed for handheld
> photography should be 1/focal length (e.g. for a 200mm lens, minimum would
> be 1/200sec) but I have seen several references on the web to the fact that
> this is different in MF photography, but haven't managed to find a formula
> for it. Does anyone have the correct formula, given frame size & focal
> length to work out the min. shutter speed?
>
> Thanks in advance
>
> Neil


From: Mxsmanic mxsmanic@hotmail.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: scanners - good enough?
Date: Sat, 27 Dec 2003

stacey writes:

> I've shot plenty of stuff handheld but I always realize
> I'm giving up image quality one way or another.

I've only noticed a difference in low light and/or with slow films.
However, that's true only for looking at the image as a whole--if I look
at the image in great detail (on a scan, for example), it's usually
possible to see a difference between a handheld shot and a tripod shot.
The difference is often smaller than commonly claimed, but it does seem
to be there. Sometimes I see that the image is slightly blurred under
very close examination, and careful analysis shows that the blur is a
motion blur, which proves that it came from the camera being handheld.

I've shot pictures at 1/8 second that I was sure would be useless, only
to discover that they were more than sharp enough. On other occasions,
I've shot at 1/30 thinking that I was safe with a reasonably wide lens,
only to see obvious blurring in the result. Tiny and light cameras are
your enemies when you are trying to shoot handheld at low speeds. My
little digital camera is guaranteed to blur just about anything at least
than 1/60 to some extent, but with care I can shoot at much lower speeds
with the film cameras (because they are all larger and heavier).


From: "David J. Littleboy" davidjl@gol.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: scanners - good enough?
Date: Sat, 27 Dec 2003 

"MikeWhy" mikewhy@my-deja.com wrote ...
> "David J. Littleboy" davidjl@gol.com wrote 
> > I compare my handheld test shots with a microscope. Fer crissakes, I don't
> > have _TIME_ to scan my test shots. I only scan frames that look sharp under
> > the microscope.
>
> Tell me a bit more about your setup. I'm interested, but think the wife will
> have me committed if I brought home a dissecting kit.

I have a 4x5 light table*, an 8x Hakuba loupe, and a 60-100x el cheapo zoom
microscope (National BF-964, the base is removable allowing it to sit on top
of the film on the light table: it's good enough to tell the difference
between tripod shots wide open or at f/22, and those in the middle f-stops).
All very plebian, but workable, stuff. Nowhere near enough to have you
committed.

If a slide looks good with the 8x loupe but not with the microscope, it's
not worth scanning.

*: Fujicolor Viewer 4x5. Uses 4 batteries or a supplied mains adaptor. I'd
like a brighter light table and a better microscope, but haven't found them
yet.

David J. Littleboy
Tokyo, Japan



From: David Littlewood david@nospam.demon.co.uk
Newsgroups: rec.photo.equipment.35mm 
Subject: Re: a most puzzling test result: slide vs negative 
Date: Mon, 1 Sep 2003 

...
If I understand you correctly, you went to all the trouble to do an 
elaborate test, but used different bodies for the slide and negative 
films. I can't understand what you were thinking of! In any comparative 
test you need to eliminate as many variables as you can. The results you 
got are meaningless, and you will have to repeat using the same body, 
and preferably the same shutter speed. 

Reasons why one body may intrinsically underperform another include (a) 
higher level of vibration (yes, even on a tripod), (b) inadequate film 
plane maintenance (poor pressure plate etc.) and (c) error in location 
of focus screen (if this is even 0.1mm misplaced, you will be focussing 
on the wrong plane). 

You don't mention how good a tripod you used. Most "consumer" tripods 
are worse than useless; while they will reduce gross movements by the 
human holder, they will not suppress any vibration from the camera. If 
you were using a flimsy tripod then the extra stop of exposure will 
probably explain why the Velvia result is less sharp. For a true test, 
use a solid tripod *and* the same exposure (using ND filters). 

Finally, you did use a cable release, didn't you? If not, random amounts 
of human hand pressure will make results meaningless. 

-- 
David Littlewood 


From: stuart phillips [stuart.phillips@rcn.com] 
Sent: Mon 1/5/2004  
To: hasselblad@kelvin.net 
Subject: Re: [HUG] 200 Series "F" WInder - and 203FE


Yes, you are right about tripod use - I've seen it quite clearly in prints
with quite respectable shutter speeds - 80mm lens with 125th or 250th
second. Often a slight loss of texture.

I ssuspect the 110 f2 is a little like the Noctilux - buy it to shoot it
wide open. With other lenses, except for portraits, if my meter tells me to
shoot at f2.8, then I need to be using a tripod and a smaller aperture
necause at f2.8, the depth of field will be unsatisfactory.

----- Original Message -----
From: "Jim Brick" jim@brick.org
To: hasselblad@kelvin.net
Sent: Monday, January 05, 2004 
Subject: RE: [HUG] 200 Series "F" WInder - and 203FE


>  Austin Franklin wrote:
>
> >I disagree. Since you were specifically talking about the 80, the 80 FE has
> >much closer focusing than the 80 CFE, which, for someone, may be a distinct
> >advantage. I have found it to be! The only real reason for the CFE is if
> >you are going to be doing fill flash.
> >
> >I also prefer the rest of the lenses in FE versions, simply because they are
> >typically, one stop faster.
>
>
> The problem with FE lenses is that they do not have a BTL shutter. A BTL
> shutter is much quieter, in terms of vibration, than a focal plane shutter,
> especially a very large focal plane shutter (2-1/4 rather than 35mm.)
>
> Deadly speeds are those between 1/30th and 1 sec. At these speeds, the
> vibration caused by the shutter beginning its travel can be seen by the
> exposure and is a significant part of the exposure. This will kill very
> fine detail and have an impact on fine detail. Shorter than 1/30th and
> longer than 1 sec have only a minimum amount of the exposure seeing the
> vibration. Thus there is a minimum impact on fine detail.
>
> For absolute optimum sharpness, use a tripod, use mirror pre-release, and a
> BTL shutter. If you hand hold your 200 series Hasselblad, FE lenses are
> good enough because the fine detail killing practice of hand holding will
> overshadow focal plane shutter vibration, which can actually be reduced by
> your hands absorbing some of the FP shutter vibration. It has been proven a
> thousand times over that hand holding any camera, even a Leica M camera, at
> speeds less than 1/500th sec will reduce the resolving of fine detail.
> Resolving fine detail is only important if you are going to make large
> prints. My standard size print is 20x24 and it goes up from there.
> Therefore, the recording of very fine detail is of utmost importance to me.
> Hence, my most used lenses are all of the CFE lenses. I do own some FE
> lenses but they are used only for special purposes.
>
> Therefore, I suggest that 200 series owners use, when possible, CFE lenses
> rather than FE lenses. Perhaps this is why more and more CFE lenses are
> being made and more and more FE lenses are being dropped from the
> Hasselblad lens catalog.
>
> If you need an extra stop (all but the 80FE) AND need to focus closer, your
> only choice is FE (used in many cases) lenses. But wide open is rarely used
> on any of my CFi or CFE or FE lenses. I suspect that the majority of MF
> photographers rarely use their lenses wide open. But I do use my 110/2 wide
> open. That's why I have it. So I can use it wide open. Bokeh city!
>
> Jim


From minolta mailing list:
Date: Sat, 24 Jan 2004 
From: "Paul Brecht" pariht@pacbell.net
Subject: Re: Anti-shake Technology

Brent,

AS in the A1 works by having the CCD on a gyroscope to compensate for
movement. Look here at the example:

http://www.dpreview.com/reviews/minoltadimagea1/Images/asmovie.mov

For the complete article, go to:

http://www.dpreview.com/reviews/minoltadimagea1/

& read the complete article...

Paul


From: rmonagha@engr.smu.edu (Bob Monaghan)
Newsgroups: rec.photo.equipment.35mm
Subject: Re: Pentax Lens Bokeh
Date: 28 Nov 2003

yes, I have tried to pick up an ADXL series dual axis accelerometer board
kit for such testing, but they are pretty rare even on ebay ;-( this would
let me monitor motion in two axes (x-y) and correlate it to the time the
shutter is open (PC flash synch).

Lots of cameras esp. medium format like bronica S2A have lots of vibration
and noise, but it is all after the film has been exposed and so doesn't
impact the image.

This is the problem with laser pointer vibration tests, unless you are
taking a photo of the vibration of the pointer on the camera taking the
photo, you can't be sure some of the motion is never seen on film as
the shutter isn't open yet, or has already closed by then... ;-) ;-) (see
http://medfmt.8k.com/mf/vibration.html )

that URL shows falloff of tests by Keppler with multiple photographers at
slower speeds. Similarly, mirror lockup can provide up to 172% higher
resolution at certain speeds than non MLU shots, again per PopPhoto tests

you are very correct that the amount of vibration effect can vary for each
shot, depending on many factors including muscle fatigue, film exposure
synchronization with heartbeat, etc.,

The only solution I see to that is multiple shots showing the amount of
degradation. I also suspect that a dual lens test chart and real world
subject would be needed to show how such slow speed effects reduce
resolution and contrast by up to 50% or more (per Erwin Puts estimate).
I have a few photo books and articles that show this impact on the same
subject, one shot with a tripod and one without, showing losses. Again, I
think this would have to be on slide film, and would be hard to see on
most web site photos (or subject to less questions/challenges if on film?)

the good news is that it would probably only take a single camera and lens
test series, with say 6 shots at each shutter speed (and one set on a
tripod?), to be convincing that there is a large loss at slower speeds
used handheld?

my favorite subject for these tests in the past was a test with a bright
light bulb in reflector, covered by tinfoil, with some holes punched in
the foil with a needle. With the Tripod, you get minimal sized point light
sources, but handheld, you get all kinds of little squiggles ;-) this
varys with holding 35mm horizontally or vertically too ;-) This also works
best with a short telephoto lens, unless you have a high powered loupe, as
the magnification from 50mm shot at 10X or so is not as convincing as from
105mm or 200mm ;-)

I think this would be a more convincing test about the degradation from
camera shake. Seeing that bouncing light pattern makes it easy to
understand how points of light get smeared, and how that kills your
contrast and resolution, regardless how good the lens might be otherwise!

I guess I should do both tests here, one for the real world impact and
effect on resolution chart losses directly, and the second light bulb test
to show how the camera shake patterns vary, but none are as good as the
tripod patterns? But it only takes a few rolls of film and some luck to
provide a pretty convincing series of shots as part of this test ;-)

grins bobm



From: john@xyzzy.stafford.net (jjs)
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Focal plane vs. leaf shutters in MF SLRs
Date: Sat, 03 Apr 2004 

 
rmonagha@engr.smu.edu (Bob Monaghan) wrote:
> [...]
> even more shocking, the value of mirror lockup may surprise many
> photographers, including many whose current cameras don't offer this once
> common feature, see http://medfmt.8k.com/third/mlu.html chart of Pop tests
> telephotos gained circa 100% (135mm) to 170%+ (300mm) when used with MLU
> on sturdy tripods at speeds around 1/15th to 1/60th second etc. Yeech! ;-)

Thanks for the pointer to the excellent articles, Bob.

One more thing - I can show how the wrong cable release can lead to camera
shake. My favorite release is the long (about 12") thin type, however I
got a 'deal' on some short, high-tech heavy releases. What a huge mistake.
Sighting down the side of a 500mm lens I could see the lens and camera
move as I depressed the release. Bad! I switched to using the camera's
self-timer and the differences in the negatives were profound.	 



From: "Bandicoot" "insert_handle_here"@techemail.com
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Focal plane vs. leaf shutters in MF SLRs
Date: Mon, 5 Apr 2004 

"David J. Littleboy" davidjl@gol.com wrote 
[SNIP]
> I wonder, though, that maybe a cable release is the wrong idea. On a
> solid tripod I'd think that holding the camera with both hands and
> slowly squeezing the shutter release could provide added damping
> of shutter vibration.

I've been convinced of this for a long time: I reckon to press down on the
camera/lens on the tripod to add damping at any speed down to about 1/4s or
so, and go with the release/timer only for exposures longer than that. All
with MLU if at all possible.

My testing has been qualitative rather than quantitative, but so far I'm
convinced.

Peter



From: "Russ" russell_UnSpamMe_@thehovel.net
Newsgroups: aus.photo
Subject: Re: Do it yourself Image Stabilisation
Date: Sun, 11 Apr 2004 

"Ken Chandler" news(at)kenchandler_com wrote
> Just came across this link on Slashdot:
>
> http://www-2.cs.cmu.edu/~johnny/steadycam/
>
> It is designed for video, but thought someone here might find it useful to
> try with their still camera.
>
> I've adding it to my to-do list to have a try 'one day'(tm).

The true Stedicam system is much more complex and capable than what is
described on that site - there are a quite a few home-made designs floating
around on the net that come a lot closer to the real thing, though not to
say that this guy's idea doesn't help getting a smooth shot, but the
steadicam system stabilises in all axes - in fact the motion of the camera
is so divorced from the operator that it literally floats, requiring a great
deal of skill to get it to point where it's meant to.

For more info, have a look at:
http://kiwifilm.com/steadfaq.html
and
http://entertainment.howstuffworks.com/steadicam.htm

Of course, all a little irrelevant to stills work, but still some remarkable
engineering.

Russ.


From: Scott Coutts scott.coutts@med.monash.edu.au
Newsgroups: aus.photo
Subject: Re: Do it yourself Image Stabilisation
Date: Mon, 12 Apr 2004 

Miro wrote:
> "Douglas MacDonald" nospam@technoaussie.com wrote
>>I don't often get into "Miro" centric threads but this time I know that you
>>are making a comment without the slightest knowledge of the subject -
> Miro.
>
> It would make more sense to tie a string on your hand and have a loop to put
> your foot in at the other end. The whole pipe idea is a fricken joke. Just
> 10 days to late.
>
> Perhaps one should be using lead pipe and eating food with ones hands
> afterwards. Anyone that ventures into this chasm of nonsense must surely
> feel the need to be validated. Which I do not.
>
> Whether it is string or pipe., the addition of tension to ones hands muscles
> increases the tonic frequency of the nerve pulses from a light infrequent
> pulse (prone to shaking) to a greater continuous rate (no inherent shaking).
> The secondary effect is to activate a different subset of muscle groups
> normally not engaged in cameras handheld, due to the lack of weight.
>
> By increasing both the tonic rate of nerve firing and the type of muscle
> group you can effectively stabilise your hand for hand-held. Some people can
> do this without added weight and others cant.

I think that this level of physiological detail is only going to account
for very small movements that the steadycam deals with. I dont think the
major part of it's operation is designed for that purpose. This is a
better description of how it works:

http://kiwifilm.com/steadfaq.html#A2

Scott.


From: " Miro" miro01@hotmail.com
Newsgroups: aus.photo
Subject: Re: Do it yourself Image Stabilisation
Date: Sun, 11 Apr 2004

"Douglas MacDonald" nospam@technoaussie.com wrote
> I don't often get into "Miro" centric threads but this time I know that you
> are making a comment without the slightest knowledge of the subject - Miro.

It would make more sense to tie a string on your hand and have a loop to put
your foot in at the other end. The whole pipe idea is a fricken joke. Just
10 days to late.

Perhaps one should be using lead pipe and eating food with ones hands
afterwards. Anyone that ventures into this chasm of nonsense must surely
feel the need to be validated. Which I do not.

Whether it is string or pipe., the addition of tension to ones hands muscles
increases the tonic frequency of the nerve pulses from a light infrequent
pulse (prone to shaking) to a greater continuous rate (no inherent shaking).
The secondary effect is to activate a different subset of muscle groups
normally not engaged in cameras handheld, due to the lack of weight.

By increasing both the tonic rate of nerve firing and the type of muscle
group you can effectively stabilise your hand for hand-held. Some people can
do this without added weight and others cant.

The resistive force of a string tied to a weight or your shoe is more than
adequate and does not require a plubmers permit.

Now if you dont understand the theory then kindly refrain from assuming I
have anything in common with you.


From: " Miro" miro01@hotmail.com
Newsgroups: aus.photo
Subject: Re: Do it yourself Image Stabilisation
Date: Sun, 11 Apr 2004 

"Ken Chandler" news(at)kenchandler_com wrote 
> Just came across this link on Slashdot:
>
> http://www-2.cs.cmu.edu/~johnny/steadycam/
>
> It is designed for video, but thought someone here might find it useful to
> try with their still camera.
>
> I've adding it to my to-do list to have a try 'one day'(tm).

errrr ........ just get a bag of sand, a string and tie it to the camera.
The inertia of the sand will do the same thing.

BTW. Keep the sand bag just barely touching the ground.

Comes in 4 models. long, short, retractable and high performance string.


From: "Gear>id O Laoi/Garry Lee" glee@iol.ie
Newsgroups: rec.photo.equipment.medium-format
Subject: Re: Does the 1/focal length rule apply for hand holding medium format?
Date: Wed, 16 Jun 2004 

You don't HAVE to use a tripod.

If you brace the camera by using a neck strap, or press the top of the
viewfinder against your forehead while using your magnifier, it helps.
I regularly shoot with quite slow speeds. I'm just back from holidays where
I shot pictures of two people we were talking to in a restaurant, zoom lens
at about 50. Both at 1/8 second. One crystal clear, one slightly fuzzy. I
can always shoot sharp at 1/30 with 50 mm and have had a shot published shot
handheld without bracing at 1/4 second. Only you can say what you can do.




From: bmitch@comcast.net (Willhelm)
Newsgroups: rec.photo.equipment.large-format,rec.photo.equipment.medium-format
Subject: Re: Newer Tiltall Tripods
Date: 26 Jul 2004 

One rather unheralded feature of the old Tiltall heads was a viscous
pad which damped small vibrations from tranmitting to the camera. New
Tiltalls have only the customary rubber pad.



From: ThomasH henrymot@some.net
Newsgroups: rec.photo.equipment.35mm
Subject: Re: PopPhoto's IS tests (Aug 2004) - Canon/Nikon/Minolta/Sigma
Date: Sat, 10 Jul 2004

"Stephen H. Westin" wrote:
>
> Alan Browne alan.browne@FreeLunchVideotron.ca writes:
>
> > Stephen H. Westin wrote:
>
> > > Actually, I would like to know more about their methodology. Camera
> > > shake seems like a phenomenon that would be hard to repeat accurately,
> > > especially with different cameras.
> >
> > Just take a few shots hand held after a long day on an empty stomach.
> > You will shake.
>
> Ah, but not repeatably. We want to compare the effectiveness of
> different pieces of equipment.
>
> --
> -Stephen H. Westin
> Any information or opinions in this message are mine: they do not
> represent the position of Cornell University or any of its sponsors.


They photographed a target with with black dots on white background
in bottom half. Than the DxO was estimating "blur factor" in a
range 1 to 5.

A reference "blur 1" was chosen to be an average of shots made
by the camera mounted on a tripod, set to 1/100s with 100mm lens
and released by a remote release. The blur factor of 2 is a
minor fuzziness, approx. what 'blur' in Photoshop delivers, etc.
You need to see the reference images to see the extend of the
fuzziness. Blur factor 2 serves as a measure of exposure time
delivering "Good" result, 3.5 was chosen to be "Marginal."

The hand-held test was made using 4 different photographers,
averaging to 3500 shots, later evaluated by the DxO analyzer.

This appears to be a good base for believable results.

Alan asks sure about the Minolta: It looks good what the AS
technology does! It really does. Take the edition, they show
an image made at 1/15s with and without the AS.

Of the three EVF cameras they obtained the following results:

at time good marginal
Canon S1 IS : 38mm 1/4 1/2
Minolta DiMage A2 : 28mm 1/4 1/2
Lumix DMC-FZ10 : 35mm 1/4 1/6 <--?? misprint?

C 380mm 1/50 1/25
M 200mm 1/25 1/15
L 420mm 1/25 1/15

The gain over non stabilized image is +2 at the long end, at
the low end 1.0 in Canon and Panasonic, versus 1.6 in the
Minolta. Speaking of the Lumix with Elmarit: Astonishingly
Phil Askey left out this camera from his dpreview tests,
but I found 2 tests of this Lumix, one of them is on
Steve Digicams.

Thomas




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