View Full Version : Compur 1 needs a spacer?

Marco Annaratone
3-May-2008, 07:15
Hi everybody!

I just bought a used 180mm Symmar-S in Compur 1 to mount on a 6x17 Fotoman. I made sure that it came with a retaining ring because I thought it was pretty much all there was to it, instead it seems that it needs a spacer, i.e., the one typically used in Copal 3 lenses between the front lens / shutter and the lensboard. In fact, a screw of the Compur 1 aperture mechanism in the back makes contact with the board and when I tighten the retaining ring it becomes pretty much impossible to change the aperture because this screw is pressed against the board and blocks the aperture mechanism. Hence, my conclusion that it needs a spacer.

The problem would show up on a standard GF lensboard as well, so I am wondering if owners of Compur 1 mounted lenses have a way to get around it, or they know who sells this spacer. I looked at SK Grimes site but could not find such a spacer for Compur 1's.


Peter K
3-May-2008, 07:41
You can use any ring, also a piece of hard cardboard will work fine.

Glenn Thoreson
3-May-2008, 16:23
Drill a hole for that screw to sit in, or better yet, just remove it as most do.

Jon Wilson
3-May-2008, 17:00
A rubber plumbing ring which you can get at hardware store.

Marco Annaratone
4-May-2008, 02:39
Thank you all, I should have probably posted a picture before ...

... anyway, the nasty screw that creates problems is the one in the pix that the arrow points to. The circled one can be removed or a hole can be drilled to accommodate it, but the nasty one moves while changing aperture - so no hole - and I guess can't be removed either.


I think I will put together some improvised spacer. Not that I'm "Mr. I-know-all-there-is-to-know-about-GF" but I found it odd that I never heard of this problem before. Hence my suspicion that there is something out of the ordinary (or faulty) with my shutter. Again, the problem is not with the dark screw in the circle, I did hear of people taking _that_ away, but with the one pointed by the arrow.


4-May-2008, 02:49
You need a decent washer, perhaps even the Schneider one. Try an automotive mechanic, I used to have shim type washers that would almost certainly fit in my toolbox.

You're right not to remove the screws, the locator screw that is sometimes removed is close to the thread for the retaing ring, usually it's faster to just use a V file to allow this to locate, it stops the lens revolving as it's fitted.


Rick Moore
4-May-2008, 07:36
I have a late 70's Compur 1 with exactly the same construction. I solved the problem by mounting the shutter on a flange, rather than using the jam nut. The flange provides the relief necessary.

Glenn Thoreson
4-May-2008, 18:51
Yep, I see what you mean. You do need a washer to space it out a little. I thought you just had a problem with an anti rotation locating screw. I just cut that kind of spacer out of card stock.

5-May-2008, 02:11
The screw that is causing the interference shouldn't be doing so. Your shutter appears to have had an incorrect replacement installed. From your photo it looks like the slot is buggered-up, adding to my suspicion of prior, incompetent service. I've seen this happen before. The correct screw has a very flat head, to provide the necessary clearance. If Schneider USA can't provide a replacement, you ought to be able to find one from a supplier of metric hardware. Or you can do what I have done in the past and cannibalize one from an old, broken lens from a 35mm camera (Canon breech lock lenses have lots of small screws inside them). Just be careful not to shift that aperture linkage around. That screw you need to replace controls the relationship between the aperture lever and the internal linkage for the blades. Also, the factory part is kind of soft, so don't over-tighten or you'll strip the threads on the screw (likely what happened in the past, leading to the screw replacement).

Marco Annaratone
6-May-2008, 12:04
Thank you all, thank you mrossano!

The kind of help you get in this forum is really invaluable, always.