RF off

[moretto]

I'new here and lost in zillion topics, so forgive me if there's an answer to my question somewhere around, and i missed it.

So, i have a Zorki 4, and Fed 4, perfect condition and love them. Finally, got a Leica M3, with ruined Summicron 50 and Elmar 90. No problem, got a Jupiter 8 and 39mm to M mount adapter. Works fine, but the RF seams to be off by cca 5 cm on 1m (fully open f2) Otherwise OK. Can this be fixed? Or is it less trouble to be ignored?
THX in advance

 

[xayraa33]

welcome, does the J-8 focus ok at 1M at f2 on the Fed and Zorki?
if it does, then the lens might have to be shimmed to work well on a Leica.
the Sonnar focus shift can also play a part in causing this, but this more pronounced on the f1.5 lens .

 

[oftheherd]

I'll bump this up for someone else to see who can give you a better answer. I have read enough that I am sure the answer is yes. What I can't tell you is what it might cost, nor who might be the better to send it too, or if it would be worth a DIY.

EDIT: Well, see there, someone else has already jumped in with better advice.

 

[moretto]

That was quick!! Thank You. And yes, the lense focuses fine on both Zorki and Fed. I tested it with good old measuring tape. When I turn the lens ring on 1m, the focus is on 1m perfectly. But when i focus to 1m through RF, the actual focus is on 105-106 cm.
And as I'm from Croatia, English is not my first language, so now I'm going to find out what "shimmed" means. Now where's that dictionary...

 

[xayraa33]

here is a site by a member of the RFF regarding shimming a Jupiter 3, this can apply to the almost similar Jupiter 8, to get the idea.

http://www.pentax-manuals.com/repairs/j3service.pdf

 

[moretto]

Now, that's a project! Thank You xayraa33! Most useful!