Fixing/shimming Jupiter 8 lens

[Redseele]

Hello everyone,

As everyone who has a Jupiter 8 and a Leica camera (I use it with my M9), I also have problems focusing. I know why (different standards) and how to solve it (shimming it). But where I do I get proper shims for doing this? and, how thick and size should they be?

Thank you, thank you!

 

[dexdog]

a good place to starrt would be doing a site search for posts by rff member sonnar brian. brian is an expert at fixing these type of lenses. in general, shims are made of a lot of different materials such as paper, card stock, thin sheet metal or whatever else you have the ability to cut. i know that brian has provided the formula for computing the thickness of the shims in some recnt posts. maybe brian will check i soon.

 

[Ko.Fe.]

Just cut them from paper with nails sissorrs. Use lens block as template for inner diameter.
It takes time to practice.
One was enough most of the times. I used paper from old fashion square white piles for notes.

 

[Redseele]

Thank you for your suggestions. I didn't know that I could just use paper for this. I will do it that way and hopefully I'll be able to take better photos with the Jupiter 8 🙂

 

[Sonnar Brian]

Typically increasing the shim by ~0.1mm will bring the focus into close agreement on a Leica. "But" it can vary by a large amount, depending on the individual lens. I've had lenses that required 0.5mm and more to correct the focus. Best to measure how far the focus is off at minimum focus, used wide-open. Most J-8 and J-3 lenses back-focus by 1" at 36". If that is the case- the 0.1mm shim should solve the problem.