Quote Originally Posted by lacavol View Post
Colyn, it depends on the camera and lens some have the threads worn. The Leica specs are 39mm X 26tpi (turns per inch) (.977mm) and the Russian lenses are 39mm X 1mm. Read the last paragraph here on the Survival Guide: http://jay.fedka.com/index_files/Page433.htm

I have a IIIa that doesn't take Russian lenses and a IIIc that does. Yes, they are good lenses, if you find a good one.
Is this the paprgraph you refer to?

Very early FED and FED lenses used a slightly different thread pitch which would may not make it compatible with lenses with the ‘true” LTM thread pitch.
As stated in my post I said basicly the same thing.. However post war Jupiters are fully compatible with all Leica screw mount cameras as well as other Leica copies. The exception would be the J-12 which will not work on some such as the Canon P, 7, etc due to the light baffles..

All of my Leicas III, IIIa, IIIb, IIIc, and IIIf work fine with my Jupiter lens..