New member - Lens board question

[Johnp76]

Hi Everyone,

I’m John and I’m new here, this forum is a great resource so glad to be here. I have a question about lens boards. I’ve been using a Cambo monorail, but I just bought a Toyo 45a. Toyo 110mm Copal holes seem to be way bigger than the Cambo holes. Can I not use my current lenses? Thanks!

[chassis]

Welcome John! There is a lot of good information on this site, and many experienced and helpful members.

Shutter holes are pretty standard, so there should not be a difference between Cambo and Toyo, as it relates to, for example, a Copal 0 shutter hole. Can you post a photo of the Cambo and Toyo lens boards you are referring to?

The Toyo field cameras are very flexible in terms of application and lens compatibility, and they make nice images.

[Jim Noel]

Yes. you can use your current lenses. YOu just need a lens board with t e correct size hole for your shutter.

[Leigh]

Hi John, and Welcome Aboard.

Yes you can use your existing lenses.

The lensboards need to have a hole of the proper size for each lens.
The "proper size" is not necessarily obvious.

If you remove a lens/shutter from a lensboard and look at the mounting flange that fits on the back, you'll notice there's a ring around the threaded section that projects into the lensboard hole, so obviously the hole must be large enough to accommodate that.

For modern lenses, those hole sizes are standardized.
Common shutter sizes are Copal 0, 1, and 3 (there is no 2).
The correct hole diameters are:
Copal #0: 34.8mm
Copal #1: 41.8mm
Copal #3: 64.2mm

- Leigh

[Johnp76]

Thanks for responses. I’ve never had trouble with lens boards for Cambo or Sinar, all the boards have matched the lens as they should. It’s with the Toyo 110mm x 110mm that are confusing. I think I’ve read some misleading info. I bought a supposed 40mm from KEH that was referred to as a copal #0, but it measured at 43mm which ended up fitting my 210mm copal #1 lens. So I guess it wasn’t a copal #0 after all. Hopefully the toyo copal #0 is 35mm. If anyone has a Toyo 45a I would love to know for sure.

[chassis]

John, I just measured a shutter and lens board that I use with a Nikkor-SW 120/8 and Copal 0 shutter. I use a Toyo 45AII; same camera as yours, with very minor changes.

Lensboard outer dimensions are 110mm x 110mm as expected for a Toyo 45 field camera.
Hole in the lensboard for the shutter is about 34.9mm, as expected for a Copal 0. I measured with a digital caliper. I might be 0.1mm off in the measurement.

On the Nikkor lens brochure, the mounting ring centering pilot is identified as 34.6mm -0.01/-0.03 which is consistent with the hole size I measured.

Let me know if you need any other measurements.

[Leigh]

Hole in the lensboard for the shutter is about 34.9mm, as expected for a Copal 0.
I measured with a digital caliper. I might be 0.1mm off in the measurement.

On the Nikkor lens brochure, the mounting ring centering pilot is identified as 34.6mm -0.01/-0.03 which is consistent with the hole size I measured.
That's consistent with the measurements I previously posted from the Copal datasheets:

The correct hole diameters are:
Copal #0: 34.8mm
Copal #1: 41.8mm
Copal #3: 64.2mm

- Leigh

[Johnp76]

Thanks Chassis and Leigh,

Very helpful info, I’ve been reading the wrong stuff obviously. Now if I could just find a copal #0 board I’d be set. Nothing at B&H, Used photo pro, or Keh. Didn’t think they’d be so hard to find.

[chassis]

John, there is one on the bay: https://www.ebay.com/itm/Copal-0-110x110mm-Lens-Board-For-4x5-Large-Format-Camera-Toyo-Omega-K-B-Canham/232969112170?hash=item363e0a8a6a:g:VggAAOSwSCZbMnCA:rk:10:pf:0

No connection with the seller. Price is good btw.

[Dan Fromm]

Have you looked on eBay?

[Shutterbug57]

Thanks Chassis and Leigh,

Very helpful info, I’ve been reading the wrong stuff obviously. Now if I could just find a copal #0 board I’d be set. Nothing at B&H, Used photo pro, or Keh. Didn’t think they’d be so hard to find.

I think this is what you are looking for. If it is and you have not already sourced one, PM me and we can do a deal with pricing better than the Ebay deal.

186044

186045

186046

[Johnp76]

Thanks for the offer, but I need the smaller 110x110mm board. Appreciate it though!