Bolex SOM Berthiot Cinor lubricating
Posted 24 September 2011 - 02:05 PM
It seems that everything is in very good condition, but the adjustment ring distance of the lenses are very difficult to turn.
I guess it is the original grease which has dried.
How can we fix this?
Posted 24 September 2011 - 09:43 PM
It's a job for a lens tech - without a collimator or a familiarity with lens mechanics it's very easy to lose the carefully callibrated back focus setting, among other potential problems.
You can have a go yourself, of course, if you're up for a challenge. Just measure and mark everything as you dismantle it (especially the point where threaded rings begin to screw together - there are typically many thread starts but only one will give the correct collimation). But even with great care, chances are the focus scale won't be reliable afterwards, especially on the wider lenses. You'd also need to source some decent and appropriate lens grease, have the right tools, and avoid damaging any sealed-in set screws or exposed element surfaces.... have I dissuaded you yet?
Edited by Dom Jaeger, 24 September 2011 - 09:43 PM.