Jupiter 3 on a Bessa R2

IF the J-3 is properly regulated to focus at 28.8mm when set to infinity, the combination should work quite well.

I have a J-3 in pristine condition that focuses on ground glass when set to infinity but the cam takes the rangefinder just past infinity. I'm not quite certain how to adjust the lens but I suspect it will require shaving a few thousands of an inch from the cam to make it coincide exactly when set to infinity.

Walker
 
Walter, before you do that, know that the lens moves in the barrel, from what I hear. There's a set screw and the whole thing twists in or out for good infinity focus.

What I've heard about any and all bright Soviet Made Standard Lenses is that they may well not focus correctly at all distances, but may be "good enough" to be of no consequence, as the J-3 is really a longer lens than the Leica 50mm standard (52mm?) so there is a cam rate difference that the Soviets designed into their cameras. It's supposed to be pretty subtle, but Dante Stella goes to some length to describe it on his site.

I've personally never tried it. I have a hard enough time getting my NON FSU stuff focusing right!
 
The J3 is a 52.3mm lens. The Leica standard is 51.6mm. If the RF indicates 36" the lens will actually be in focus at 37". The RF cam would need to be pushed in slightly, right? Pushed in, longer distance to infinity (and beyond, as Buzz would say).

The DOF at F1.5 is "almost" enough to cover this. Try it and find out. The J9 that I sold to Oscar was already calibrated to make up the distance. Try the individual lens to see.
 
On some of the Soviet 50mm LTM lenses all of the glass is in a single optical "block" or unit. The unit screws in from the front and is locked in place with one or more set screws. You can make adjustments by rotating this block and re-tightening the set-screw(s). I recently "discovered" this on an Industar 26M. There are 3 setscrews on the same ring as the f-stop numbers. Back them out part-way and the entire optical block rotates out.

-Paul
 
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