View Full Version : Copal 0 shutter - implication of bad slow speeds

28-Dec-2006, 12:40
I am thinking about a lens in a copal 0 that I can get a pretty good deal on (but not a fabulous, no-brainer deal). I've seen it in person and the problem is that the low speeds (1 and 1/2 it seems) are very sticky. The rest of the speeds sound fine.

My question is: do these shutters have different mechanisms for different speed regimes? Ie, does a sticky 1 and 1/2 have implications for the other speeds or not? If not, I can handle the missing 1 and 1/2 second as they aren't speeds I use that often (and there are ways to compensate). If it's the same mechanism, I'll just forget all about this lens.

28-Dec-2006, 12:57
As was explained to me, the slower speeds are controlled by a governor mechanism which is distict from the faster speeds - but I have zilch qualification to opine.

David A. Goldfarb
28-Dec-2006, 13:48
I haven't tried to repair a Copal shutter so take this with a grain of salt, but on many shutters, there is a retarding mechanism that controls the slow speeds. On the Compur and Ilex shutters I've looked at, this mechanism tends to gum up over time, and just needs to be flushed out with a solvent and lightly oiled. It's a very simple problem to fix. I've gotten many good deals on lenses in "non-working" Synchro-Compur or Ilex shutters with exactly this problem, and have restored them to working condition.

28-Dec-2006, 13:52
It sounds like the mechanism is still intact, because you can hear it kind of clicking away slowly and it does fire and restart. I wouldn't be surprised if what you're describing is exactly the problem, David. I'll go back and take a look at it and see if it seems worth it.

Ernest Purdum
28-Dec-2006, 19:18
If the price is really a good one, getting a CLA doesn't add a lot of cost and puts your shutter ready for many years of good service.

Carol Miller at Flutot's Camera Repair (she's on the web) is a good source of this kind of work.

Alan Davenport
28-Dec-2006, 19:31
I'll cast another vote for the DIY CLA. A $3 can of Ronsonal is enough to degum quite a few sticky shutters. Large format cameras are low tech stuff. While probably fewer than one photographer in a million has the KSA to make their own lenses, and a greater but still small number could build a shutter from nothing, maintenance of the mechanics is pretty basic. It isn't necessary to disassemble the shutter beyond removing the cover plates so you can see the insides. After you flush the gunk out and get things dried out again (I recommend the "canned air" products for this purpose, but never for anything near an actual lens) then just use a toothpick to transfer micro-drops of oil to the bearing ends of the shafts in the gear trains and other moving parts in the shutter.