Originally Posted by Barry Kirsten
This raises the question of compatibility for m42. The flange-film plane distances for the two standards are different - 45.2mm for m39, and 45.46 for m42. Granted the difference is small - 0.26mm - but I would have thought this is significant, especially at large apertures and close subject distances. What do people think? And are any of you using J8s on m42? Appreciate any comments.
«45.2mm for m39» —— well, that's *not* rangefinder-M39*26tpi
, but «Early Russian SLRs (Zenit) (not to be confused with M39×26tpi and M39×1/28,8)».
See here: https://en.wikipedia.org/wiki/Flange_focal_distance
As others mentioned, you probably won't find a 35mm-SLR-Sonnar < 85mm focal length anywhere...