Archived posting to the Leica Users Group, 2003/06/27
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 10:12 PM 6/26/2003, : "Jim McIntyre" <mcintyre@ca.inter.net> wrote: >If the M camera can mount an M lense, and focus on the film plane, then it >seems logical that that same film plane can be a digital sensor. Am I in >deep space on this? From what I've read, current digital sensors require the light rays to hit them from an "angle of incidence" that is nearly perpendicular to the sensor. Film, on the other hand, can accept light hitting it at quite an oblique angle. Wide angle rangefinder lenses, being close to the film plane, send much of the (outer portion of the) image to the film/sensor from an oblique angle. Therefore they work for film, but not with current digital sensors. SLR wide angle lenses (which are of retrofocal design, meaning they have elements designed to bend the light rays back into being mostly parallel with each other in order that the rays of interest still all hit the film after travelling the additional distance to accommodate the mirror) send all of their image to the film/sensor at a pretty-close-to perpendicular angle of incidence. Therefore they work for film and current digital sensors. Anyway, that's my understanding. For this reason it seems folks are pretty down on the possibilities of using M lenses with digital capture, at least without some kludgy retrofocus add-on that would degrade image quality, make the system much larger, and generally mess up most of the advantages of M lenses. Recent messages haven't actually used the word "impossible," but that's the feeling that seems to be conveyed. However, it seems to me that the inability of current sensors to capture oblique light doesn't mean future sensors won't be able to. Plenty of "impossible" things have been accomplished. Ok, so it might be another decade until the right sensor is made...but I, for one, can wait. I just hope someone bothers to do it. - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html