Force Fitting

You may have previously read with in the project that I bought an old brass lens which I would consider a Petzval lens. Since it wasn’t actually designed for this camera I have been putting off testing it for fear it would be a waste of time I suppose. So finally did a few tests this morning. This camera didn’t come with a lens or a lens board so I cut out a piece of card stock with the measurements of 4″x4″ and a rough hole for the petzval and just held the lens in the card stock. Well I actually seen an image on the ground glass in the back of the camera… that’s a good sign. With a little bit of adjusting it seemed to look quite good. So I decided to go to the hardware store and find something to build a decent lens board out of. The lens board needs to be ⅛ inch thick to actually fit the camera. I was hoping to find some thin hardwood but that didn’t work out so I had the store rip a full sheet of ⅛ inch mahogany plywood to ¼ sheet panels and bought one of the quarters. A full sheet was pretty cheap but I’m low on shop space. Even at just a ¼ sheet of plywood I can probably make 40 lens boards for this camera. Hold on let me do the math so someone doesn’t catch me on that…..(24×48=1152 square inches / 4×4=16 square inches) 72 lens boards if in a perfect world where the saw kerf didn’t remove material. Not bad for $5 in material and a bit of work. I can’t even buy one on eBay for that price.

So I built one. None of my hole saws were the correct size for the threads so I started with a 2″ hole saw and widened the hole progressively with a sanding wheel in my drill press. I was hoping I would be able to friction fit the lens in to the board but I took of just a little bit too much for that work. Regardless the lens is heavy enough I don’t believe I would have much faith in the lens not dropping out and smashing on the ground. I have turned the lens board so the grain of the wood is vertical to improve the strength. So now I need to find a large nut to actually screw on to the lens so it will be secured in to the lens board…. this might be a big mission all on it’s own. It has to be about a 2 ¼ inch diameter.

Moral of the story? I think this lens was a good purchase after all. The only drawback is I have zero aperture control and no mechanical shutter. This is a super manual lens! I will keep a look out for other lens’ I may be able to mount on a custom lens board. It’s nice to have options.

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