Camera shake and tripods - interesting study

eoren1

Saw this initially on crave.cnet.com but the article was skimpy on details. Below is the best I could find that offered some info (original link)

Do you know that SLR (single-lens reflex) cameras have a problem that the built-in mirrors and shutter in the main unit cause camera shake and degrade the image quality?
Though camera manufacturers and some enthusiasts have been aware of the problem, they had no idea how serious (or minor) the problem really is until recently.
However, Tani Electronics Corp and the Nishi Lab of the University of Electro-communications (UEC) introduced a measurement tool that will change the circumstances. They developed a method to easily and accurately measure the effect of camera shake correction.
The results of measurements using the new tool are as follows. The resolution of an SLR camera was substantially reduced to 1/4 or lower by the mirror shock (vibration generated when the mirror bounces up).
Next, it was confirmed that the vibration generated by releasing the shutter remains even when a picture is taken after a certain period of time from the mirror lockup to prevent a mirror shock.
Then, the Nishi Lab and Tani Electronics found that camera shake significantly worsens when a lighter tripod (approx 1.5kg) is used. Also, they conducted a quantitative investigation about the influence of the installation direction of the tripod.
"There is no point in enhancing resolution unless we take some measures to reduce the vibration of a camera unit as a whole including a tripod," said Kazuki Nishi of UEC.
When a tripod is used, the above measurements were carried out after disabling the image stabilizer, as directed in instruction manuals of cameras and lenses. And, to make sure, the researchers conducted the measurements using several cameras with the image stabilizer function turned on and confirmed that camera shake worsens.
The Nishi Lab and Tani Electronics improved the LED display used to measure the effect of camera shake correction and enabled to measure vibration caused by the mirrors and the shutter. As a result, they succeeded in detecting and quantifying the trajectory of camera shake with an enhanced temporal resolution. With the new measuring tool, various kinds of vibration can be measured and quantitatively evaluated directly from pictures taken by a camera.
"We hope that this measurement tool will be used to totally evaluate various kinds of vibration such as caused by a tripod, not just camera shake," Nishi said.

Tomohiro Otsuki, Nikkei Electronics

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So it appears that they took mirror-lockup into consideration and still saw a deleterious effect on image quality with use of a tripod. Wish they would give specifics on the tripods used and try the same with a high-end rig. Also wonder if this may be turned into a better in-camera IS solution...
E

Art Scott

using a 1.5kg pod??? that is less than a lot of cameras weigh......it is a wonder the camera did not wind up on the test lab floor...:D.............

pathfinder

Mirror slap has always been a problem, inherent in the design of an SLR - It is even worse in larger medium format cameras with much larger mirrors. Think of a 6 x 7 centimeter mirror clanging up and down inside a camera body. That is one of the lovely things abut range finder cameras like the Leica - no mirror, smaller, quieter, faster to focus than a manual focus SLR ( before the days of autofocus SLRs)

Then there is the sllding of the shutter curtain across the front of the film plain, as opposed to a simple iris shutter inside a lens 3 inches from the film.


There is no doubt these phenomena have an effect, but the fact remains that with a modern DSLR one can create images in size and sharpness and detail one could only dream about with 35mm film.

Modern full frame cameras are mostly limited by the sharpness of the glass, not mirror slap most of the time. Pro grade cameras do a better ( slightly anyway ) job of controlling mirror slap than cheaper ones.

Canon is well aware of mirror slap - they built an SLR with a pellicle mirror that did not move at all years ago - Ziggy can probably tell us the year . Instead of a moveable mirror, there was a half silvered prism in the body so that half the light went to the viewfinder, and half the light went straight into the film plane with no movement or slap of a mirror whatsoever. This meant that the viewfinder was not nearly as bright for a manual focus camera, and the film was effectively half as fast as well. With the high ISO available with digital sensors now, and modern autofocus, a pellicle mirror might be a very nice design to revisit. But it will still seem slow, and the sensor half as fast as a camera with a moveable mirror.

These phenomena are interesting to photo purists, but remember, an awful lot of published photos are still shot handheld, where mirror slap is a rounding error in image sharpness.

Art Scott

pathfinder wrote:

Mirror slap has always been a problem, inherent in the design of an SLR - It is even worse in larger medium format cameras with much larger mirrors. Think of a 6 x 7 centimeter mirror clanging up and down inside a camera body. That is one of the lovely things abut range finder cameras like the Leica - no mirror, smaller, quieter, faster to focus than a manual focus SLR ( before the days of autofocus SLRs)

Then there is the sllding of the shutter curtain across the front of the film plain, as opposed to a simple iris shutter inside a lens 3 inches from the film.


There is no doubt these phenomena have an effect, but the fact remains that with a modern DSLR one can create images in size and sharpness and detail one could only dream about with 35mm film.

Modern full frame cameras are mostly limited by the sharpness of the glass, not mirror slap most of the time. Pro grade cameras do a better ( slightly anyway ) job of controlling mirror slap than cheaper ones.

Canon is well aware of mirror slap - they built an SLR with a pellicle mirror that did not move at all years ago - Ziggy can probably tell us the year . Instead of a moveable mirror, there was a half silvered prism in the body so that half the light went to the viewfinder, and half the light went straight into the film plane with no movement or slap of a mirror whatsoever. This meant that the viewfinder was not nearly as bright for a manual focus camera, and the film was effectively half as fast as well. With the high ISO available with digital sensors now, and modern autofocus, a pellicle mirror might be a very nice design to revisit. But it will still seem slow, and the sensor half as fast as a camera with a moveable mirror.

These phenomena are interesting to photo purists, but remember, an awful lot of published photos are still shot handheld, where mirror slap is a rounding error in image sharpness.

ABSOLUTELY!!!!!!bow

Nothing like the sound of a 6x7 mirror lapping up and down during as wedding ceremony......everyone's head turns to the photog.....leaf shutters are awesome......to me the best design in the world aside from rangefinder cameras was the twin lens.....no mirror .....absolutely the quietest cameras around..........i loved my Fuji 645 rangefinder...........

ziggy53

pathfinder wrote:

...

Canon is well aware of mirror slap - they built an SLR with a pellicle mirror that did not move at all years ago - Ziggy can probably tell us the year . Instead of a moveable mirror, there was a half silvered prism in the body so that half the light went to the viewfinder, and half the light went straight into the film plane with no movement or slap of a mirror whatsoever. This meant that the viewfinder was not nearly as bright for a manual focus camera, and the film was effectively half as fast as well. With the high ISO available with digital sensors now, and modern autofocus, a pellicle mirror might be a very nice design to revisit. But it will still seem slow, and the sensor half as fast as a camera with a moveable mirror.

...

The Canon EOS RT was the only camera developed by Canon with a "pellical" mirror and it was designed to reduce lag caused by the mirror assembly. This design is sometimes reconsidered for a more modern design but the problems it introduces always prevent reintroduction (plus the somewhat dismal sales figures of the RT itself.)

The Canon 1D/1Ds series cameras use a more advanced mirror box which includes a "latch" mechanism for the mirror which helps absorb some of the mirror slap and rebound. The latch plus the shear mass of the 1D/1Ds series makes them more resistant to the problems of shake due to mirror and shutter motion.

pathfinder

We're not the only ones discussing pellicle mirror designs either - http://photo.net/canon-eos-digital-camera-forum/00RIHS

They mention the same advantages I suggested above for a modern non-mirrored DSLR.

Ziggy, you stated the RT, but this link is for a Canon High SPeed F-1 - the F-1 was always Canon's flagship pro camera back in the 70's.


Wiki talks abut the pellicle mirror here and mentions a Canon EOS 1N RS

Here is a link about the Canon RT with a nice picture of same

Photoskipper

I learnt how bad the mirror shock is in a hard way. The 5D FF mirror is much bigger than other crop bodies and the shake is also much bigger. It is so big till the mirror drop off from the assembly in the middle of shooting trip in the desert end last year.

Canon replace the stopper and mirror assembly FOC for me after that.

We may not feel too much about the mirror shake in daily shooting with normal or short tele lens. Once I use the 500 mm or with the TC, at lower shutter speed (below 100), I can see the shaking effect on the image. The 5 Kg tripod and head does not help too much. Only way to reduce the effect is to push the ISO and increase shutter speed.

Tried with couple big rubber band with close cell foam on the lens body tight to the heavy tripod seems help a little bit. Shooting with the body and long lens on a bean bag has better result.

Scott_Quier

Photoskipper wrote:

I learnt how bad the mirror shock is in a hard way. The 5D FF mirror is much bigger than other crop bodies and the shake is also much bigger. It is so big till the mirror drop off from the assembly in the middle of shooting trip in the desert end last year.

Canon replace the stopper and mirror assembly FOC for me after that.

We may not feel too much about the mirror shake in daily shooting with normal or short tele lens. Once I use the 500 mm or with the TC, at lower shutter speed (below 100), I can see the shaking effect on the image. The 5 Kg tripod and head does not help too much. Only way to reduce the effect is to push the ISO and increase shutter speed.

Tried with couple big rubber band with close cell foam on the lens body tight to the heavy tripod seems help a little bit. Shooting with the body and long lens on a bean bag has better result.

Did you attempt to hang extra weight from the center post of your tripod? I've read (but never tried) that doing so increases the rigidity and stability of the tripod.

pathfinder

When it comes to tripods and long glass, heavier is almost always better for shooting.

Not so much for carrying, unfortunately....

ziggy53

I've seen photographs of one of the noted wildlife photographers, I think it was Art Wolfe, using 2 tripods; one for the camera and the second tripod for the lens.

Photoskipper

Scott_Quier wrote:

Did you attempt to hang extra weight from the center post of your tripod? I've read (but never tried) that doing so increases the rigidity and stability of the tripod.

Yes, I did it very often. The camera backpack is one of the best weight I use.

I also tried to use 2 tripods, one for the lens mount and the other has a bean bag to support the front part of the long lens and tight it with a big rubber cord. It seems to be the best way to reduce shaking.

But using 2 tripods may not be an option for field shooting and bird photo. It is too heavy and not able to track the birds.

pathfinder

ziggy53 wrote:

I've seen photographs of one of the noted wildlife photographers, I think it was Art Wolfe, using 2 tripods; one for the camera and the second tripod for the lens.

Once you begin to use two tripods, weights, pillows, MLU, cable release, and Better Beamers, it really begins to feel like a job, rather than an avocation:D

Art Scott

ziggy53 wrote:

I've seen photographs of one of the noted wildlife photographers, I think it was Art Wolfe, using 2 tripods; one for the camera and the second tripod for the lens.

I have had to do just this during my film shooting with medium format and 300 mm lens.......I have also done tripod under lens and good monopod under camera.

As Scott Q. suggested....a sandbag hanging off the center column can do wonders.....but I have only done that in high winds and it did stabilize the pod a great deal.

Art Scott

pathfinder wrote:

Once you begin to use two tripods, weights, pillows, MLU, cable release, and Better Beamers, it really begins to feel like a job, rather than an avocation:D

Oh come on now.......we do what ever to get the pix!!

Photoskipper

pathfinder wrote:

Once you begin to use two tripods, weights, pillows, MLU, cable release, and Better Beamers, it really begins to feel like a job, rather than an avocation:D

I am thinking to try the fluid filled professional video camera tripod. It sounds more solid and better damping effect. But it is just too expensive to buy one to try. Will see whether I can get one from my friend for a day or two.