Archived posting to the Leica Users Group, 1996/12/11
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 03:48 PM 12/11/96 -0500, you wrote: >At 12:18 AM 12/11/96 -0400, Dan C. wrote: > >>Don't get me wrong, I admire Leica very much, but anyone who says that >>autofocus cameras can't focus as well as MF cameras has obviously never used >>an autofocus camera. My primitive Minolta 9000 (a first generation AF >>camera) will equal or better the focusing accuracy of a MF leica in all but >>dim lighting conditions. > Marc replied: >Even the AF manufacturers -- Nikon, Canon, Minolta, &c -- admit that AF >accuracy is not as great as MF. Try a test with your Minolta -- use FAST >prime lenses (f/1.4 or faster) wide open. You'll find a lot of cases in >that circumstance where the narrow focus will cause a focusing problem. The >problem exists -- but you cannot see it -- with the relatively deep >depth-of-field on a slow (f/5.6 or so) zoom lens, which is about all anyone >uses with AF. > >Leica and Contax, whose virtues are FAST prime lenses (F/1 Noctilux, f/1.4 >Summilux and Planar designs, especially the 1.4/75 Leica and 1.4/85 Contax >lenses), are more nervous about this than are the AF camera makers, and with >very good reason. > >Hope this is clear! > I am afraid I don't get the point. It's certainly true that casual photographers who buy cheaper AF SLR's probably buy relatively slow zooms to go with them. But Nikon, Canon, etc. make prime pro lenses that are just as fast or faster than Leica's and Contax's, so there's no reason why Leica and Contax should be more worried about focusing. Canon makes a 50 f1.0 and an 85 1.2, for example, and Canon will tell you their autofocus system will focus those lenses just fine, and that it will do very well in low light (by sending out a beam of light to help the focus). In theory, Leica says, a manual focus SLR will focus less accurately than an M up to about 135 mm. But that proves nothing about an AF SLR. Don't forget that an AF SLR, like a RF camera, operates by triangulation. Can you give some proof that AF SLR's focus less well than manual ones--and under what conditions? Charles E. Love, Jr. CEL14@CORNELL.EDU