[Leica] 40mm lens

[Frank Dernie <FrankDernie@compuserve.com>]

Stanley E Yoder wrote

Strange, that. It would seemingly have nothing to do with the cam and
RF; rather, with variances in mount-to-filmplane distance, which I would
think Leitz would make to very close tolerances (using shims, etc.).


Stan
I believe the problem with variable suitability of CL lenses is to do with
the method of rangefinder adjustment on the M.
Since the cam on the 40mm lense is a steep cam the axial position of the
cam follower roller on the cam would be influenced by the side to side
position of the cam relative to the center of the lens mount. Since the
rangefinder is adjusted on the M by an eccentric mount of the follower the
lateral position of the follower can and probably does vary from camera to
camera. This will mean that 40mm lenses couple differently to different Ms.
cheers Frank