Which FSU Camera?

[Laika]

I did have a weird experience with the 3M however -- my black J-12 won't fit on it (the thread seems to bind). My silver J-12 fits perfectly, however, as does the J-3. All three lenses fit fine on the Fed 3a!

With the back off and the shutter open on B check the RF cam position as you try to mount the J-12, its likely to be the culprit binding on the back of the lens. FED's often need the cam position tweaked to mount a J-12, it could be the problem with your 3M. Try comparing the cam position in relation to the lens mount on both your 3M & 3a with the lenses off. Nice camera the 3M

 

[hugivza]

Thanks Lawrence!