M-adapters - separate for FSU register?

[Armoured]

This may be a stupid question, but this is how I usually learn. Given that FSU thread mount lenses are (apparently) on a slightly different register, leading to focus problems - would it not be possible to make a slightly different M-Mount adapter specifically for Fed/Zorki lenses?

Obviously if this were possible, it would make it much easier to use these lenses on newer cameras without having to shim them to the Leica register (rendering them no longer as accurate/useful on FSU bodies).

Any technical experts could clarify this for me?

 

[Sonnar Brian]

No, all that happens if the M-Mount adapter is made thicker is the Cam and the optics are both moved out. When you shim a lens to correct the actual focus for the RF of the camera, you move the optics with respect to the Cam.

And it's not a stupid question in my opinion... I spent two hours doing just this when I had the "DOH!" moment of why it was not working.

 

[Armoured]

Ahhh...

Ahhh...

Ahhh, I think I get it. So the cam would still have to be adjusted/shimmed (which may not be possible) or the focus of the camera would have to be, which would pretty much leave you in the same situation. Thanks for clarifying this for me.

Too bad.

 

[JohnnyT]

Following the stupid question...

Is there a way to easily correct a 50mm Jupiter 8 (last version)? Like a how to for dummy... ;p

Mine giving me headache and I really want to use it on my leica...

 

[Sonnar Brian]

I post my projects on ziforums.com, and under the repair/projects section show how to do this on a Jupiter-3.

This thread shows the shims and basic process for making a Zeiss Sonnar into Leica mount. The principle is the same for adjusting the J-8.

http://ziforums.com/showthread.php?t=360

You probably do not have a TTL viewer, so use an exposed negative or glass at the film gate, and a loupe to check the focus.