Archived posting to the Leica Users Group, 1997/04/22
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]>>Could some one explain to me all of the variations of the Leica >>reflex camera lens mount. 1,2, and 3 cam, why Tamron has a R4 >>ONLY adapter. What was Leica thinking? Actually, they were thinking. There was a huge change in camera technology between the 1960s and the 1980s. In most other cameras brands, you would have completely forgotten about lenses from the 1960s and 1970s by now. The additional cams were necessary to go from non-TTL (one cam) to TTL metering (two cam) and to add programmed autoexposure (three cam). This was not unique to Leica. Canon, for instance, went through the R, FL and FD (and then new FD and EOS) mounts, and Olympus and Pentax made an even more drastic change from screw to bayonet mounts in the same time period. On Leica SLRs, the third cam is all that is needed for the R cameras (like the R4 only adapter, which should work in any R camera, BTW); the other 2 are there for backwards compatability, so some newer lenses omit the older cams. Three cam lenses will work on any camera. Most lenses can be modified to the three-cam configuration. I think that any lens will actually work on any camera, if you can live with the loss of features (for instance, you may need to use stop down metering or may loose autoexposure), but I'm sure that someone will point it out if I'm wrong. Nikon and Leica are the only major SLR brands (as far as I know) whose 1960s lenses will work on modern cameras without some kind of adapter, either as-is or with minor modifications. - - Paul