Tech question: Schneider semi-autoExakta lens - gummy aperture link...

[Luddite Frank]

I have some nice Schneider-Kreuznach lenses for the Exakta ( f:4/28, f:1.9/50, f:3,5/135) - these are mid-1950's black lenses with the semi-automatic aperture control ( stops-down as you depress the shutter plunger ).

(Photo borrowed from Captain Jack's Exakta Page)

On a couple of these, the plunger seems a bit stiff, and the aperture is sluggish to return to the open position after the shutter plunger is released.

My suspicion is that the plunger linkage to the aperture is gummy.

Has anyone else dealt with this ?

I'm tempted to try some gentle "flood-cleaning" with Ronsonol, but don't want to bugger-up the lens... 😕

 

[tunalegs]

I've only ever had the later Schneider lenses with the little lock lever on the PAD arm. I don't think you have anything to risk at all by putting a drop of naptha into the button (probably from the camera side is best). If it's anything like the later lenses then the mount and arm are simply held on by some flat head screws and it's easy to remove the whole rear of the lens and do some dusting and cleaning.