Reply to thread

Message: <blockquote data-quote="BrianS" data-source="post: 352520" data-attributes="member: 6381">The filter ring on the J-3 is not removable. On some lenses- such as the Nikkor 5cm F2, it can be unscrewed and replaced.You are left with a choice of "hacking" a step-up ring into the lens, which I've done on some lenses. OR- with as many bad-glass Jupiter-3's out there, get a fixture and transplant the glass into it. That's my preferred solution, I've done it on a number of them.You need to get the correct fixture. KMZ glass can only go into KMZ fixtures, and they are all the same. Early ZOMZ lenses, 1956~(ABOUT) 1963 have a rear fixture to hold the triplet in place, it screws into the main barrel. Lens on the left is complete, one in the middle shows the triplet removed. Later lenses have a one piece fixture, on the right. I've interchanged glass between Valdai and ZOMZ "onesies" before. [ATTACH=full]199407[/ATTACH]You will need a spanner to remove the retaining rings, and possible a suction cup to pull the middle triplet out. If you get a complete lens with just a bad front element, you can usually just replace that. Makes it easier. After transplanting glass, a fine-tune to the shim is usually required.It is best to unscrew the barrel from the focus mount and verify the type, whether or not the rear triplet is in the separate fixture. After 50+ years, someone might have been doing some swapping around. Kind of like I do.</blockquote>