Fixcinater
Never enough smoky peat
I've got a pretty nice example of the 100mm f/3.5 lens head with the focusing adapter R-B for use on R, FL, FD cameras with a problem in the aperture blade mechanism.
I've got it mostly pulled apart and cleaned up, including the aperture blades which were stuck open by grease. During the cleaning process, I found that the retaining ring for the main large blade pivots has room to move towards the front of the lens and therefore let the rearward/smaller pivots out of their pivot points. When that happens, the aperture loses function, of course.
I don't see any way to ensure this main retaining ring stays tensioned towards the rear.
Any help out there? Not a lot of info on the web about the mechanics of this lens. Any thoughts would be appreciated!
I've got it mostly pulled apart and cleaned up, including the aperture blades which were stuck open by grease. During the cleaning process, I found that the retaining ring for the main large blade pivots has room to move towards the front of the lens and therefore let the rearward/smaller pivots out of their pivot points. When that happens, the aperture loses function, of course.
I don't see any way to ensure this main retaining ring stays tensioned towards the rear.
Any help out there? Not a lot of info on the web about the mechanics of this lens. Any thoughts would be appreciated!
John Shriver
Well-known
There's someone selling Canon RF lens parts manual copy on eBay. That might show you what goes where.