Archived posting to the Leica Users Group, 2000/07/31
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> "Miro Jurcevic" <miroj@ozemail.com.au> says: > The physics are against you all the way. First the mirror goes clunk and > shakes the entire casting. Then in the SLR versions, two shutter curtains > move at hundreds of K's per hour in a fraction of a second. That's enough to > move the camera. > > No matter what your human body is doing, the camera body, unless it is M*, > is doing a cha-cha all over the place. The difference only shows above 8' x > 10' and then it is a seriuosly limiting factor in image size. This brings up something I've been wondering about. Leicas have a single cloth shutter. SLRs have a shutter plus a mirror, plus an automatic diaphragm. Vibration from the mirror and diaphragm has often been cited as the reason why many people can use an RF at least one shutter speed notch slower than an SLR. Gary Reese's lens test of Olympus Zuiko lenses showed this principle dramatically--the same lenses tested better with mirror lockup and diaphragm prefire than without them. See http://members.aol.com/olympusom/lenstests/default.htm. So how about the new Konica Hexar RF and Voigtlander/Cosina Bessa R? The Bessa uses an additional shutter as a light cap, and a noisier Copal shutter. Does this cause any appreciable vibration? How about the Hexar RF? Perhaps this is a good excuse for one of our empiricists to test the same lens (normal or medium tele), target and film on a Leica M, a Bessa and a Hexar, and see what the results are. Reductio ad absurdum (sp?): Perhaps we should all ditch our Leicas, and start using leaf shutter cameras like the old interchangeable-lens Kodak Retinas. Or lobby Solms to bring back the Compur-Leica in M mount :-) Or maybe put a leaf shutter in the Tri-Elmar! - --Peter Klein Seattle, WA