Stiff focusing and the rangefinder wedge!

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POSTI-Tuomo

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Just wondering, why is it that some FSU LTM lenses will focus very smoothly with my Zorki 1 and some are horribly stiff. All lenses are cleaned and not distorted at all. Could it be that the rangefinder wedge does not sit completely flat against the lens cam, causing unwanted friction and therefore hampering movement.

An example. My Ind-22 won't focus easily when mounted on a Zorki 1 body, whereas my Jupiters will. But when I mount the same I-22 on my Zorki 4s, they behave just nicely...

Any ways to correct this problem? Would careful twisting of the wedge yield desired results? Or is it just too risky? I understand the RF arm/wedge can be broken quite easily, not to mention ruining the calibration (tedious, yet easy to fix).

It is a matter of aesthetics, mostly. I just like the look of a Zorki 1 / I-22 combo. Maybe I'll discover its optical qualities as well if I get to use it enough.
 
I noticed similar thing. One I-26m will get stiff arond 1.5m on FED-2, but is smooth thoughout the range on other cameras... I don't think it could be the RF wedge... I was thinking it might be a distorted lens mount... the paper shims under the lens mount aren't flat - they are stepped (1 shim, 2 shims...) and when the mount is tightened too much it could easily bend...
 
I have noticed

I have noticed

the same thing. I have a Ind 61 that was stiff on my Fed 5 but freed up nicely on the Fed 2. I normally use my J12 on the Fed 2 but decided to try it rather than disassemble the lens. Glad now that I did.

Thanks😀
 
I've had this issue on a couple of mine. Try loosening the lens mount screws then retightening them a bit at a time in an X-pattern. I think the mounts can distort easily, being aluminium. Re-tightening in this way makes sure they're kept flat. The other thing is not to overtighten the mount screws, they don't need to be too tight. This has resolved the issues I've had anyway...
 
It's good to check things every now and then. Three of four mount screws in my Fed 2b, were loose. I loosened the 4th one a bit, then re-tightened in the 'x' pattern wolves3012 mentions above. Focusing with a J8 is silky smooth, and focusing with an I-61, about 80% as good. mike
 
POSTI-Tuomo said:
Just wondering, why is it that some FSU LTM lenses will focus very smoothly with my Zorki 1 and some are horribly stiff. All lenses are cleaned and not distorted at all. Could it be that the rangefinder wedge does not sit completely flat against the lens cam, causing unwanted friction and therefore hampering movement.

An example. My Ind-22 won't focus easily when mounted on a Zorki 1 body, whereas my Jupiters will. But when I mount the same I-22 on my Zorki 4s, they behave just nicely...

Would careful twisting of the wedge yield desired results? Or is it just too risky? I understand the RF arm/wedge can be broken quite easily, not to mention ruining the calibration (tedious, yet easy to fix).
Click to expand...
Not so much bear flat, as bear properly. It could be right on the edge.
What you are saying points very much to the RF follower arm. I had the same problem with a FED-1 using its own lens. It wasn't "horribly stiff" but certainly not kosher while others were OK, and the FED-50 was fine in the Zorki-6. It can be no surprise that the follower arm gets bent out of wack over the years, and I guess a measure with a cheap vernier will show differences between your lenses. There doesn't have to be much difference to cause a problem. As yours is so stiff, it is likely that, even with lenses that are OK, the follower only just makes contact. Even so, the restorative bend is minimal, just 1mm or so.

It is easy to fix but I believe you should take the top assembly out of the body, in order to get the best access. The Oleson website shows how. You will soon be hearing horror stories with words like "calibration" and/or "collimation" in them. You can safely ignore them.

You might find these links helpful

http://www.rangefinderforum.com/forums/showthread.php?t=39964
http://www.rangefinderforum.com/foru...ead.php?t=9779
 
ZorkiKat said:
What makes you believe that these can be ignored?
Click to expand...

Heh, I, as for one, couldn't ignore "calibration". Managed to mess with the focusing ring while taking a lens off my Zorki... of course it went off the 1 meter mark. I hate calibrating the RF. 😀
 
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