John haeger said:
Thanks for all the info I was won a Fed-s from *bay for $72.50 that has a j12 mounted to it
and thought it might be nice to look for the 50mm that should be with it. Camera is in the mail and should be here in a day or so. guess I will have to try my canon 50mm 1.8 (black and sliver) or the j3 or j8 thank you again for the info. john
Hi John
Let's hope that the J-12 on the camera now was there because it was used with the camera, and not just put there by the seller or its previous owner for the sole reason of having a lens on that camera.
First, FED-S, like the other early FED cameras, didn't use the standard LTM pitch (the threads will not correctly accomodate the true LTM thread) and second, their lens working distances varied from the standard LTM register of 28,8mm.
The first would mean that many true LTM lenses may have difficulty in mounting in those early FED. At worst, it could also destroy the lens mount. FED started getting the standard lens mount pitch after the war.
The second issue would mean that the lens will not be able to focus properly. 35mm wide angle lenses may be able to produce acceptable images because of their inherent depth of field. Wide aperture lenses or longer ones will not be able to focus right- producing either back or front focus effects.
Your Canon 1,8/50 may face a double whammy: "incorrect" lens thread mount and bad focusing. Even if you could mount it, you may not be able to focus it right.
However, there is also a good chance that the camera may have been revised
sometime. One way to tell is if the 35mm Jupiter mounts with its index marks readable from the top. And if its lens mount has been changed, chances are, its lens working distance would have been modified too, to accomodate the later Russian and true LTM lenses. Modifying the lens working distance (as well as adjusting the RF system) to accomodate your Canon lens is not really difficult to do. With some tools (a 1.4mm jewellers screw and a small pair of pliers) and the
right instructions, you'd probably be able to do this yourself.
A word about Canon and other non Russian LTM lenses: some of them used tongue-shaped RF cams isntead of the full-barrelled ones. These should not be used on FSU rangefinders as these would be almost impossible to mount, and can cause damage to the RF or to the lens itself.
Jay
