Archived posting to the Leica Users Group, 2001/01/18
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]David - You're right - it would affect *both* the RF and the film-plane focus. But since all non-50mm cammed lenses have nonlinear movement, the RF and the focus can diverge if the film-flange distance is not right. 50mm lenses have a 1:1 correspondence between lens distance from film and RF focus. It's hard to explain easily, but the point is that with wide and tele lenses, you can have problems if the adapter is too thick or thin. Cheers Dante On Thu, 18 Jan 2001, Rodgers, David wrote: > Dante > > >>- -- Fourth, your LTM adapter can be out of tolerance, or it can be worn. > Self-explanatory.<< > > How can an LTM adaptor affect focus? Focus is determined by the movable part > of the lens contacting the rangefinder cam. The movable internal lens > mechanism is independent of the outer barrel. If the back plane is moved, or > the rangefinder (cam) is out of adjustment, or the base of the internal lens > mechanism is worn; I can see how these might affect focus. But the front > mount (i.e. an LTM adaptor) would have to be noticably messed up (at an > angle vs out of tolerance) for it to affect focus. Just wondering if I > missing something. > > Dave >