dexdog
Veteran
I have had a 1951 Jupiter 3 (with ears) for a while that I finally got around to shimming. The serial number is 5103647. The existing shims were too thick at about 0.5mm and the lens back-focused significantly, about 42 inches on the one-meter wide open test. I experimented with thinner shims and found that 0.35mm was pretty good. The problem is that when I screw the lens back together, the aperture ring is stuck tight. I can turn the apeture ring easily if I unscrew the optical block a little bit, perhaps 15 degrees or so. The lens elements are nice and clear and the lens is a great performer. I do not know why the apeture is binding, and would like to get advice about how to treat the issue. Thanks!
As might be expected, part of the fixture for optical block is brass. The scratches visible on the variable stand-off ring were there when I got the lens. I have not seen any CZJ serial numbers on the thing, the highest number J-3 that I have personally seen CZJ numbers on is 5103453. I bought this one on the chance that it had CZJ numbers, but no such luck
As might be expected, part of the fixture for optical block is brass. The scratches visible on the variable stand-off ring were there when I got the lens. I have not seen any CZJ serial numbers on the thing, the highest number J-3 that I have personally seen CZJ numbers on is 5103453. I bought this one on the chance that it had CZJ numbers, but no such luck
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