Sticky "Studio Shutter" repair

[Emile J Schwarz]

I bought a lens with a sticky "studio shutter". Has any one ever tried cleaning one of these? Or have a link on how to clean one?

[Ernest Purdum]

I haven't tried to clean one, but I partially opened two of them. When you take the front cell off, two rings come loose, the one which has the apertures marked and one below which actually controls the diaphragm. At this point you will see screws (five, on the ones I looked at) which hold on the plate which actually exposes the mechanism. One of these may never be opened again, because two of the (brass, apparently) screws had had the heads ruined. Make sure your screwdriver fits very well before trying to loosen these screws. At this point I gave up, not wanting to similarly damage the good one.

If there is no oil on the leaves (which always causes stickiness. The likely problem is the movable ring to which one pivot of each blade is attached, and the surface on which the ring rubs. These generaly respond well to ordinary cleaning methods including use of very fine abrasives if there is corrosion build-up. A very small amount of a dry lubricant such as molybdenum disulphide might help. If the actual lubricating substance is in a liquid suspension, let it dry thoroughly before reassembly.



I probably don't need to tell you that the very thin blades are fragile.

[David A. Goldfarb]

I've repaired one, and it was simple enough that I could figure out how it worked just by looking at it.

When you disassemble the diaphragm, note that one leaf is a double leaf, and the adjacent leaf slips between the two halves.

Mine has an air release, and the piston was bent out of position causing some sticking, and it just had to be bent back, and that solved most of the trouble I was having.