Copal 3 lens board question

**robertraymer** · 8-Apr-2020, 10:11

So I have been looking for a Cambo lens board for a copal 3 lens, and cant seem to find one. I do however find a number of combo boards drills with 62mm holes. What shutter would need a 62mm hole? A Copal 3 should be 65 and a copal 2 should be roughly 42mm correct?

Also, how difficullt would it be to file out a 62mm metal board the extra 3mm to fit the copal 3 lens. I have done it with wood boards, but never with metal boards. If I cant find a copal 3 board Im tempted to try filing down a 62mm board, but don't want to ruin it.

**Corran** · 8-Apr-2020, 11:43

Are you sure? No 62mm holes indicated here: https://www.largeformatphotography.i...ole_sizes.html

3mm is too much to try to file out, unless you have a lot of time.

Also, what about this?
https://www.ebay.com/itm/Cambo-copal...d/254556867496

**BrianShaw** · 8-Apr-2020, 13:47

A few years ago I had similar problem. Camera repair shop machines the opening to correct size and mounted the lens. I paid about $35... one of the better investments I’ve ever made.

**DMS206** · 8-Apr-2020, 14:32

62mm would work correctly with a thin metal lens board such as cambo. 65mm would work better with a thick wooden board where the retaining nut would go through the board, being held on by the flange. I just measured one,
Dave

**Bob Salomon** · 8-Apr-2020, 14:33

Originally Posted by BrianShaw

A few years ago I had similar problem. Camera repair shop machines the opening to correct size and mounted the lens. I paid about $35... one of the better investments I’ve ever made.

+1

**Greg** · 8-Apr-2020, 17:14

Hand filing 3mm to make the hole larger... in the past have done it many times. A good vice, a half rounded coarse file, and music in the background are all you need. I cover the front of the board with white masking tape and mark the opening I'm after with a thin Sharpie. When I was a student at RIT didn't have a vice and it was a pain to do even with wooden boards.

**robertraymer** · 8-Apr-2020, 17:48

Thanks all.

I ended up finding a seller on eBay that had one, and who may even be able to drill out a hole for a barrel lens I like to use in the future. The one linked in the first reply was not the correct board.

Still, I am confused as to the sizing. I know that a Copal 3 is 65mm and still do not know what a 62mm hole would be for, but it seems like it is being suggested that you need a 65mm hole in a wood board but not a metal board? How is that so?

**DMS206** · 8-Apr-2020, 18:19

Originally Posted by robertraymer

Thanks all.

I ended up finding a seller on eBay that had one, and who may even be able to drill out a hole for a barrel lens I like to use in the future. The one linked in the first reply was not the correct board.

Still, I am confused as to the sizing. I know that a Copal 3 is 65mm and still do not know what a 62mm hole would be for, but it seems like it is being suggested that you need a 65mm hole in a wood board but not a metal board? How is that so?

**DMS206** · 8-Apr-2020, 18:29

The thread diameter on the shutter is 61.8mm. On mine the retaining ring is 65mm outside dimension, with a step to a larger diameter, and it is 9.5mm thick, which is thicker than your lens board, so if you had a 65mm hole, it would not tighten, and could spin freely.