Archived posting to the Leica Users Group, 1996/12/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>At 09:22 AM 12/6/96 -0500, you wrote: >>It's not that AF 'reduces optical quality': the concern from Leica and >>Zeiss is that AF ACCURACY is not good enough to replace manual focusing for >>critical work, and, apparently, critical work is all that these two >>companies are interested in their customers doing. Thus, both the R system >>and Contax lack AF. (Yes, yes, I know about the new Contax -- but that is a >>specialty camera only.) >> >>Marc >> I think the concern about accuracy is historically correct, that is, it's at least a partial explanation of why Leitz abandoned its autofocus project. But it's just not true today, especially with longer lenses. Indeed, even with short telephotos some AF systems can be focused accurately than an M with the same focal length. The only comfort we can take is that an AF SLR is, in concept, much closer to a rangefinder camera than is a MF SLR. As for the new Contax--well. I am sure they don't see it as a "specialty camera," but as central to the line's survival, as a way to juice up their sales--indeed, I'll bet they expect it to become a relatively big seller. But I don't pay tribute to Zeiss for it, since it has a serious problem that other autofocus systems lack. The performance of any lens with a floating element will suffer if it's focused by moving the whole lens back and forth, rather than by turning the lens barrel, which other AF systems do. I'm also not confident that zooms will be too happy, though I'd need to hear from someone who understands optical design better than I do on that. Charles E. Love, Jr. CEL14@CORNELL.EDU