View Full Version : Copal shutter service in the UK?

30-Jul-2012, 08:23
I purchased two Rodenstock Lenses with Copal 1 shutters from a seller in the USA on this forum, I have tried contacting him about the shutters, unfortunatlly he is not getting back to me.
The lenses are as new but had been sitting unused for a few years, does this effect the accuracy of them?
I've done some test sheets and everything seems to be about two stops+ underexposed, I'm exposing in the 1/4 -1 second exposure times.
Is it just a case they needed a good service? Is this quite cheap (I hope) and can anybody recommend someone good in the UK if this is the case.

30-Jul-2012, 09:31
You can test teh slow speeds accurately with a microphone and a program like Audacity or Sound Forge. Shutters run slow not fast which would give over exposure, have you allowed for bellows factor/extension.

B on W in Bristol are excellent for shutter servicing, they've done a few of mine.


30-Jul-2012, 10:23
Hi Ian,
No bellows extension as I was focused about twenty feet away with a 210 & 90mm. When would that come into effect with those two lenses?
Yes I'm getting a shorter exposure, do they get faster or slower if left for some time?

I tested my light meter against two others and processed b&w and colour, cannot think what else it could be? no reciprocity at this speed? Just consistant underexposure of negs!
If both lenses are underexposing it seems a rare thing to happen on both the same, the 90mm is just slightly less underexposing than the 210mm.

30-Jul-2012, 10:32
For shutter speeds in the 1/4 to 1 second range, you can get a fair idea of their accuracy by comparing them to another shutter of known good accuracy. Fire the known good shutter, then fire the shutter under test. If they seem about the same duration, there should be no way the test shutter would cause two stops of underexposure. To get two stops, the good shutter would be firing at 1/2 second and the test shutter would be firing at 1/8 second. It should be easy to detect that much difference by just watching and listening to the two shutters.

30-Jul-2012, 10:58
Yes that is what I'm finding so confusing! These are the only two lenses I have and both fire for the same duration against my stopwatch.
Maybe I should get my meter tested, however that tested ok against my other meter?

This is the first time I have been photographically stumped like this. Fuji have also take the tests sheets from my London lab to test.

30-Jul-2012, 13:54
I'd check how you're metering. 2 stops under-exposure is rather odd. I've not had a shutter run fast unless totally shot, which I doubt is the case here.