Yes they are not common and are also quite expensive so when I saw one in excellent condition well below the normal asking price. I wrung my hands, told myself I was silly and not to do it, wept a little, turned my sporran upside down and shook a few bawbees (small denomination coins) out of it, mortgaged the cat and bought it before some other enterprising collector got to it before I did.
Tom, unfortunately I know the itch when one sees a hard-to-find lens. A few times I came across one, had no money to spare, and I convinced myself I did not need it, somebody else bought and I felt really bad for a long time like a kid deprived of promised candy.
The front optical block screws off in normal Komura style but the focusing element does not part in the middle "Sonnar-style" like many other Komura telephotos do. So this is one that I will have to cover new territory with. The Uni-adapter ends are supposedly exchangeable but removing the FD mount is not necessarily giving me access to the helicoid. I think I am going to have to find and remove the focus limit pin first (before I can even see the helicoid drives). As this is a short lens I am likely looking at least at a double nested helicoid - so it is best left to a long lazy day when I am not in a rush.
I envy you the understanding of the inner workings of lenses. I am so ignorant. But perhaps this stops me from buying more lenses - particularly ones I would need to work on a lot.
Best
Jarek
Jarek,
I now might have pulled apart and mostly repaired 30+ lenses (maybe quite a lot more as i have not been counting). It is a good mental vibration when success has been achieved and the lens may only have needed a good clean. But I have had some spectacular failures and have been tearing my hair out in frustration on quite a few occasions - even it I have glued the hair back on later when it suddenly “worked”.
I am no expert and every new-type lens is a bit of an aventure but I am gradually getting more experienced on figuring out the “way into” a lens which is usually the hardest part of the exercise. I usually spend a reasonable amount of time simply inspecting a lens and trying to work out the disassembly procedure before I even contemplate touching a tool or trying to unscrew anything.
Practice seems to be improving my chances and making me quicker but it can be a very frustrating exercise. Some lenses of course seem to be made in a way to discourage “amateur repair technicians”. Good tools, patience, mechanical sympathy and a tray to work within are essential.
The biggest issues are breaking or losing screws and slippage on, obstinate threaded, seemingly unremovable lock rings.
I have a “naughty box” of lenses that I need to try and fix when I get around to it - an inevitable by-product of buying second hand lenses.
I can be quoted: “If you buy enough old lenses then sooner of later you will have to become a lens mechanic”.
