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Mirror Slap: Best and Worst Nikon SLR's?


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Thomas K. , Dec 03, 2011; 02:59 p.m.

High mirror slap is performed at Nikon headquaters with EVERY succesfull camera. It's a form of "high fives" using SLR mirrors. They can be very loud, aspecially with accompaning cheers (all in japanese). Low mirror slaps are as loud as high ones. But all this pales to the legendary chest mirror slaps performed by the designers of Pentax 6x7 after it's succesfull release.

Andy Collins , Dec 03, 2011; 04:15 p.m.

My Nikomat FTN seems to have not only mirror slap, but mirror 'bounce'! I'm sure it doesn't actually bounce but it's a pretty involved mirror slap action. I've had 3 FTNs and they all behave this way.

Peter E , Dec 03, 2011; 05:21 p.m.

John: Moving parts inside the camera (mirror, shutter) can create enough of a momentum (mass times velocity) that translates into movement of the camera ("camera shake"). A sturdy tripod (large mass relative to the moving part inside the camera) that is well connected to the camera (sturdy tripod head with a stiff connection to the camera) will prevent this. If the connection to the camera is not sufficently stiff, the mass of the tripod won't be able to keep the camera steady. However, in addition, there may be a tiny amount of elastic give between shutter/mirror, image sensor, and lens that could, in principle, create a movement of the sensor relative to the lens creating some "sensor shake". The tripod would not have any mitigating effect on this. However, I presume that the camera body of even the cheapest camera is sufficiently stiff to avoid this type of "sensor shake" that is entirely within the camera.

Bruce Rubenstein , Dec 03, 2011; 06:14 p.m.

The flex (relative movement) is between the camera's tripod socket and the main structure that has the mirror box and that the sensor assembly is mounted to. Back in the traditional film camera body days, the tripod socket would have a flange that was screwed directly to the body's main casing. The front and back of the camera's chassis would extend down to the inside of the camera base plate. When the mounting screw of a quick release plate plate along with the tripod socket, the outer edges (front and back) of the camera's chassis would be drawn against the plate. This gives a reasonable wide, stiff base for the camera's attachment to the release plate. (There was very flex between my quick release plate and my Nikon F3 even when tapping the end of a mounted 180/2.8.)

Modern Nikons (at least starting with the F100 that I've examined) use at least two methods of attaching the tripod socket to the camera. The F100, D200 and D300 )Didn't look at internal pictures of manuals for the single digit pro models.) attach the socket to the inside of the bottom base cover. Although the bottom is an alloy casting, it's not very thick and will flex when longer, heavier lenses are used. Cameras like the D80, D90, D5100, D7000 have the tripod socket attached to an alloy stamping that's attached to the body at the front and rear of the camera. It works as effectively as mounting the socket to the bottom cover in the other cameras. Mount the camera with lens to the tripod and put some pressure on the end of the lens with a finger where it contacts the camera body and quick release plate, and one can feel the relative movement between the two.

The effect of the flex depends on the body, lens, tripod, etc., and the shutter speed used. Bob Atkins did a study years ago where along with taking pictures, mounted accelerometers to the camera and lens to measure vibration (Bell Labs guys do real science fair experiments), and found that mirror induced image blurring happened primarily between 1/4 and 1/30 sec. A couple of stops above or below that range and mirror slap is a minor factor. The blurring is most obvious when using long focal length lenses or doing macro photography. Also, for a given lens the effect is greater with a cropped sensor body (all other mechanical elements the same.) Once one starts using lenses that have tripod collars the body flex issue obviously goes away.

For anyone who is interested, I was using an Induro AT214 tripod with Manfroto 054 series head (both rated for 22 lbs) and a Manfroto 190 tripod with a Bogen 3030 tilt/pan head. Since I was too lazy to keep getting up and down, I only extended the legs enough to look through the view finder while sitting on my desk chair. I used D200, D80 and D7000 bodies and 180/2.8, 105/2.8 VR micro, Tamron 70-300 and 50/1.4 AF-D lenses. I was taking pictures of a resolution target.

John Crosley , Dec 03, 2011; 06:14 p.m.

For a while when I re-took up 'street' photography, I grabbed my trusty old ELs (reworked Nikkormats with AI lens connectors) popped on AW-1 auto winders, and then whenever I took a photo with the winder attached the whole world knew that I had taken a photo -- after the first photo was taken there was no chance of a subsequent photo being taken clandestinely unless at a convention of deaf people.

The AW-1 auto winder was itself a piece of work -- one of the noisiest pieces of camera machinery to be made by Nikon.

However, having started with a Nikon F and a Nikkormat (precursor to the Nikon EL, I believe), I can say that although the shutter slap NOISE was significant, I often hand held those cameras at extremely low shutter speeds (even as low as one exposure hand held at 2 seconds -- yes, really, two seconds, even though it is hard to believe now that I'm older and a bit shakier and only able to hand hold at 1/2 to 1/3 second or so under optimal conditions), and that exposure, a time exposure of a waterfall with a 135 mm telephoto stopped down, is sharp as can be and is in my portfolio now (one of my very few surviving color - chrome - photos from long ago).

I never was able, no matter how low the speed with those noisy cameras - Nikon 'F', Nikkormat or EL - to find any evidence of vibration from mirror slap. It may have been there, but I've been looking at some early work of mine with very high magnification (200x) and find no evidence of mirror vibration in that early work. (All film of course.)

The theories espoused above, relating to the physics of why and how shutter vibration should and might work seem quite sound; the question is how much does it really affect work in the field?

In my experience, not at all, even in the landscape work I did with subsequent digital cameras such as the D2 and the D2X, and a variety of other film and digital cameras (20 or 30 in all).

I understand that the highest and best advice is to get a tripod, mount the camera/lens combination on it and use it, and for non-VR lenses at small aperture, nothing could be more sound advice. However, a decently high shutter speed, good optics, good depth of field and excellent holding technique, may make a tripod less necessary even for landscapers, than some pros espouse.

(I don't post all my landscapes, so please don't go looking in my portfolio for them.)

One has to remember that in certain exposures at high enough speed, by the time the mirror 'bounces' the exposure may already have been made, thus obviating any deleterious effect of supposed 'shutter bounce' suggested above.

I long ago learned to separate the 'noise' of a loud shutter from the supposition that somehow the shutter noise was an indication my photos were going to be shaky or indistinct -- it was an equation that just didn't seem to work out in practice, though it sounded good in theory.

There may be instances where the theory and the results do overlap and maybe considerably so.

Caveat: If I were shooting calendar landscapes with any camera, just to be sure, I'd probably be carrying and using the highest quality and strongest tripod with every shot, just to be on the safe side . . . . . .

It just wouldn't hurt, notwithstanding my above experience.

John (Crosley)

Daniel Johnson , Dec 03, 2011; 09:44 p.m.

Interesting question. I've always thought that my F100's mirror makes a loud bang, while my FE just has pleasent "s-p-r-i-n-g." Of course, what those sounds have to do with actual vibrations, I don't know.

Randy Hargraves , Dec 03, 2011; 11:34 p.m.

I agree with the earlier post on the F100. I've shot it at 1 sec + exposures on tripod and the slides are razor sharp.

Rodeo Joe , Dec 04, 2011; 05:04 p.m.

Bruce, I think we're in agreement that the coupling between camera and tripod is crucial, but your mention of quick-release plates and an 054 ballhead gives me concern that there may be some weaknesses in the coupling chain that you've overlooked.

I'm well prepared to accept that our milages may vary. I was simply relating my experiences some years ago with an F2 and a few other film cameras using a variety of tripods. The tripods used ranged from an old Kodak studio stand weighing about 20lbs, through a Linhof (model unknown, but a mid-weight one), a hefty Gitzo and a Manfrotto 155 with basic 3D head. I rejected use of a Benbo out of hand as too flexible and vibration-prone for telephoto use. Any head with a rubber mat was also rejected as being too flexible, as was any ball-head with its major weak point - the stalk of the ball.

My findings were that use of a lens tripod-mounting generally resulted in worsened camera shake, due to a "see-saw" vibration mode that was very hard to prevent. If the lens wasn't too heavy, vibration was reduced if the camera itself was screwed to the tripod. If the weight of the lens dictated using its own mount, then an extended platform with space for wedging rubber or foam under the camera body proved the best solution. Use of hands-on shutter release was often sharper than using a cable-release or self-timer, but this was very dependent on the shutter speed used. Out of all the techniques tried, the one that had the least statistically significant effect was locking the mirror up.

I spent a lot of time and burned a lot of (admittedley outdated) film trying to find the best technique and tripod combo. It all basically boiled down to coupling and damping. Once that was sorted out, the weather was the main culprit in affecting sharpness. Wind induced vibration, heat turbulance and mist all had far more effect on image quality than any vibration from the camera itself. So I still maintain that if the tripod, camera seating and vibration damping are adequately addressed, then mirror "slap" plays a very minor part in reducing image quality.

David Bebbington , Dec 04, 2011; 11:00 p.m.

So I still maintain that if the tripod, camera seating and vibration damping are adequately addressed, then mirror "slap" plays a very minor part in reducing image quality.
Can't agree. I once had a Pentax Spotmatic plus 2 or 3 SMC lenses in great shape. In any shooting situation (handheld or tripod, high or low shutter speeds), this outfit did not produce sharp pictures. The same lenses fitted to a Leica via an adapter gave superb results. Nikons are far more durable than Pentaxes, but the same principle nonetheless applies.

Ian Rance , Dec 05, 2011; 05:09 a.m.

With cameras like the FM3a and its mirror raise/self timer mechanism it is very easy to just give it a quarter twist to allow a 3 second break between mirror raise and shutter fire. When your subject is not moving nothing will change in that time and I use it as standard practise. With the F3 and its proper lock up lever I actually use it less as it means more fiddling and more chance of a mistake being made.

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