JW PHOTO
Member
The vibration is caused by the impact of the mirror slapping into the frame of the body when you release the shutter. It is present in the Hassy, obvious in a Pentax 67, and non-existent in a Rolleiflex (or any other TLR). It is most problematic at the slow end of the hand-holdable shutter speed continuum- between say 1 second and 1/15th, maybe up to 1/30th. Faster than that, there isn't enough time for the vibrations to record. Slower, and they fail to record as well because they don't last long enough. Oddly, the lack of sharpness they cause will be more noticeable when the camera is on a tripod. Hand-held, your hand is more likely to induce softness by its inherent instability than the mirror slap is.
I don't know about that? I tested my 500C/80mm f2.8 years ago and I could see(with a loupe) a minute difference between mirror-up on a tripod and just shooting normal at 1/60th of a second. At 1/125th second things seemed to even out. I would still not worry at 1/60th since the difference was so small, but I don't like going below that if I can help it. If the picture is important and I do have to go slower a tripod+mirror-up is used. Just me of course! I do the same when I shoot with the Pentax 67. I'll admit I can hand-hold at much slower shutter speeds with the Rollei due to the way it's held and braced with a neck strap, but I still use a tripod if the shot is worth it. JohnW