Lens board too thin

[Winger]

Hi all. I bought a 300mm lens which I originally intended to use with my Chamonix, but then decided to use it on a 5x7. I bought a lens board that fits the camera fine and fits the Copal 3 shutter BUT isn't thick enough. There's too much play and the retaining ring is about 2mm from the board. Everything is screwed as tightly as I can get it. Is there a usual way to solve this? Are there shims that are easily available on the web? What do I search for? Could I use a cut up piece of a yoga mat instead?

Sorry for all the newb-type questions, but everything I know about LF I learned by doing or from here.

[Dan Fromm]

I've used paper shims between shutter and board.

[jim_jm]

If you can find metal, plastic or rubber washers with a large enough inside diameter (~65mm), or you could cut your own shims out of cardboard or thin hobby wood. Probably not necessary to destroy a yoga mat - might be too spongy and it's bad karma...

[reddesert]

What kind of lens board / how thick? Are you sure there is no anti-rotation pin sticking out of the back of the shutter? A Copal shutter will often fit on a fairly thin lens board, but sometimes there is a little pin on the back that prevents rotation by fitting into a hole in the board. If your board doesn't have a matching hole, then the shutter doesn't fit square to the board and can't be screwed down. If this is the issue, you can usually remove the pin with a small screwdriver, or drill a matching hole in the board.

[Andrew Plume]

Cardboard or paper as both suggested seem to be the cheapest and most convenient way to go and I'm sure that the front board retaining screws will oblige

rgds

Andrew

[Tin Can]

Is it Copal 3?

Did you use the spacer ring?

https://www.largeformatphotography.i...l=1#post126954

[Mark Stahlke]

Copal 3 shutters were fitted with two different spacer rings - a thin one and a thick one. Chances are you have the thin spacer ring and need the thick one. You can either acquire the proper spacer or DIY some shims as others have suggested.

[Tin Can]

Chinese Copal 3 spacers are available for now on eBay

Copal 3 shutters were fitted with two different spacer rings - a thin one and a thick one. Chances are you have the thin spacer ring and need the thick one. You can either acquire the proper spacer or DIY some shims as others have suggested.

[Winger]

I'll try to take some pics to show, but I don't think there is a spacer ring (so that's probably part of it). While there is an anti-rotation pin, that isn't what's blocking the board. If the board had a hole for the pin and it was in it, then there'd be even more space between the back of the board and the retaining ring. Though the pin doesn't really stick up very much.

It is a Copal 3, of course. The camera is a B&J 5x7 and I got the lens board on eBay (maybe it isn't exactly right?). The board is 5mm thick at the hole for the lens.

It will take some pretty thick paper to make up the space, which is why I thought of the yoga mat (we have one that's already been cut to protect some areas in an old car). Is mat board ok? I have plenty of that around.

[Tracy Storer]

"+1" on "you're missing the spacer ring".