DIY Recessed Lens Board: waterjet, powdercoating, and of course, lasers

I recently decided I needed a wider wide-angle lens to take in the vastness of some of the vistas out here in the west. So I found a little 65mm lens from my peeps at Midwest Photo, for a price I could rationalize.

“Little” turns out to be apt: the lens requires a mounting hole of only about 26mm, which is smaller than any lens board that I have…or that I could find to purchase. There aren’t too many people, in the grand scheme of things, that still use large format cameras. Of those, only a small fraction use my particular brand and model of camera, and of those, apparently, nobody uses a dinky lens like this one.

Not that I was going to buy one anyhow, of course. Not with TechShop’s tools at my disposal!

I think most of the official lens boards that I have are cast aluminum. I don’t yet know how to do that. Another option would be to mill what I needed out of a solid block of aluminum. I don’t know how to do that, yet, either.

What I do know how to do is use the waterjet, and I’m going to jump on any excuse to cut through metal with high-pressure water.

My original plan was…dumb, and involved trying to TIG weld thin aluminum sheet. It did not go well. Knowing how to TIG weld aluminum is a completely different thing than being able to actually weld aluminum. There are photos…that will not be published.

The gulf between knowing how to weld and being able to weld well is vast.

Plan B was to cut rings out of thick aluminum plate, then bolt them together. This worked out much better.

In the end I could probably get by with one thicker ring, but I wasn’t sure how much recess I would need, and how it would all fit into the camera, so I made multiple rings so that the whole assembly would be modular and flexible.

After I got all the aluminum cut, I tested out a new “Black Wrinkle” powdercoat, which looks pretty sweet, then of course I put that in the laser and etched my name and website into it.

After bolting it all together I tested for light leaks. I was pretty sure that the aluminum plate, powdercoated with a product called “Black Wrinkle”, was not going to be light tight, and it wasn’t. Since the overlap on each piece is about half an inch, and I’m dealing with collodion with an ISO rating of something like ISO 0.2, I’m not too worried, but since I can, I lasered a few foam gaskets to go between the aluminum layers.

Here it is again, mounted on the camera: