Originally posted by Lowell Goudge Actually the lubricant is probably from the focusing helix and zoom cams. If it is sprayed on the elements then someone has attempted to clean the aperture mechanism with com Essex air to get the oil off the blades,
Oil on the blades is what makes them stick, they should be bone dry to work properly
This would require full disassembly and cleaning to fix
I figured that is where the lubricant came from for most of it. It is the kiron stove pipe version that has a reputation for the helical grease migrating everywhere. Sticky aperture from lubricant is a common problem with them but I got lucky on that part. The front of the aperture is dry. The rear has some shiny spots like a little lube got on it but not enough to make it malfunction. The blades still open and close and snap back fine. I could see compressed air having been part of the problem the way lube is everywhere but if it has been dissembled they did a very careful job. There is not a single mark indicating it has been disassembled. I don't see how it got in the rear two sealed areas though unless it was dissembled or it got in there when the lens was first made and then spread. You would think that if someone fully disassembled it with such care they would clean the lens but who knows.
I'm hoping that after cleaning the rear two areas (already done) and the front areas (not done yet) it will be good enough to be usable and I won't have to tear into the helix. I have torn lenses all the way down before and know it could use a full tear down' clean and lube, but I would really like to salvage it and am hesitant to take any unnecessary risks.