Copal shutter diameters

[Paul Coppin]

Since the discussion on cliches left me with nothing to shoot with conventional lenses, I'm converting all of my large format cameras to pinhole ( besides, it appears the lenses are worth more on ____ then ever) ;) :).

For copal 0 and 1 shutters, is there a standard filter/ring that will screw into the front of the shutter? I measure the diameter at 29-30mm but don't know about the thread. Anybody actually know?

[Jim Rice]

http://www.skgrimes.com/products/index.htm

[Michael S. Briggs]

There are tables at http://www.skgrimes.com/products/index.htm and http://www.rtsphoto.com/html/copal2.html: 29.0 x O.5 mm for Copal 0 and 40 x O.75 mm for Copal 1.

I think I've seen the product you describe listed for sale, maybe on eBay.

But wouldn't it be easier to mount a pinhole to a lensboard? I think you will find that your exposures will be so long that you won't need a shutter.

[Paul Coppin]

I forgot about Grimes' site, thanks for the reminder. Zeroimage sells a screw adaptor for copal shutters, but at $169, a bit pricey.


But wouldn't it be easier to mount a pinhole to a lensboard? I think you will find that your exposures will be so long that you won't need a shutter.

Yes, that's not at all difficult (and I have done that already). Some of the exposures are measured in a few seconds, so I thought use of shutters I already have would reduce shake at faster speeds. We'll see what I wind up with!

[Donald Qualls]

Paul, I've mounted a pinhole in one of my dial-set #1 Compur shutters at a total cost of about eight cents (pro-rating the fractions of this and that used, and not counting my time). I unscrewed the glass, cut a circle of black posterboard sized to just slip past the threads (it bottoms on the taper just ahead of the shutter), punched a hole in the center to accommodate the pinhole, then made a collar from a strip of the same posterboard that, when taped to the base, fits snugly in the threads. Tape on the pinhole, and the unit slips readily in and out of the shutter's front threads (easily replaced by the glass when I want that back), at virtually no cost (probably the most expensive piece was the several inches of black masking tape for assembly). One could even make several with different size holes. They also weigh effectively nothing, unlike yet more glass...

Of course, I made my own pinhole for it, too; I bought $2 worth of .001" brass shim stock almost two years ago, and at the rate I'm using it, might possibly have to buy another such piece sometime before I die (but then again, I might not).

[Paul Coppin]

Paul, I've mounted a pinhole in one of my dial-set #1 Compur shutters at a total cost of about eight cents (pro-rating the fractions of this and that used, and not counting my time). I unscrewed the glass, cut a circle of black posterboard sized to just slip past the threads (it bottoms on the taper just ahead of the shutter), punched a hole in the center to accommodate the pinhole, then made a collar from a strip of the same posterboard that, when taped to the base, fits snugly in the threads. Tape on the pinhole, and the unit slips readily in and out of the shutter's front threads (easily replaced by the glass when I want that back), at virtually no cost (probably the most expensive piece was the several inches of black masking tape for assembly). One could even make several with different size holes. They also weigh effectively nothing, unlike yet more glass...

Of course, I made my own pinhole for it, too; I bought $2 worth of .001" brass shim stock almost two years ago, and at the rate I'm using it, might possibly have to buy another such piece sometime before I die (but then again, I might not).


I was thinking something similar after I pulled the lenses out one of my copal 0s. I am making my own pinholes in some shim weight 6061 aluminum, so I haven't entirely swung to "Pinholes R US" :) That sounds like a plan - easy to do and easy to get rid of when i decide to go back to shooting cliches LOL!. :) :)