If I was going to micro drill stainless steel to make a pinhole, what thickness should I use, and where could I source it? So far locally I have found .010 in 430, but I think it is still a little thick. Recomendations?
If I was going to micro drill stainless steel to make a pinhole, what thickness should I use, and where could I source it? So far locally I have found .010 in 430, but I think it is still a little thick. Recomendations?
This is probably well-known in the world of pinhole experts, but then again, maybe not; I found it in a 1930s Kodak book: use a blunt point such as a carpet needle or rounded center punch to make a dimple, supporting the stock on a piece of wood and tapping the needle gently. Then use a sanding block to gently thin the opposite side of the dimple until a hole is created that is round and of the proper diameter. Having tried it, I can say that it works just fine with brass shim stock, and also with aluminum from a soft drink can.
One advantage over a drilled hole is that the edges of the opening are knife-edged, which is theoretically better than a short cylinder. Also, there will be no burrs, as often occur unless the stock is sandwiched tightly between heavier material before drilling.
To clarify what I'm doing, I know I could buy them, or laser drilled brass, etc., but my intention is to fabricate every part of this camera that I can reasonably make by myself. The camera will be an 8x10.
I've been tempted to try self-adhesive aluminum foil tape, but maybe remove the adhesive from a section first. I think the adhesive is thicker than the aluminum itself.
I don't do well with pin poke type pinholes, though, and it would be hard to work on the aperture edges with the adhesive near it.
Aren't pie "tins" the "classic" pinhole material? That and aluminum foil wrap.
I'm sure there are a lot of people that favor beverage cans filled with beer... you have to empty them before making the holes!
Aren't pie "tins" the "classic" pinhole material?[ /QUOTE]
Aluminum pie tins are what I have used. For blacking I use a sheet of black paper with a 1/16" hole backing up the pinhole.
The dimple and sand works the best because, as mentioned by Greybeard, it leaves a knife edge. I use a sharpening stone ['Moonstone, Case'] to sand the back. I glue the dimpled square of pie tin to the table and run the stone over it so it is as parallel to the aluminum as I can make it.
I put the pinhole in the enlarger for examination - make sure it is round, there are no burrs - and also to measure the size. Size is the hard part to control with the dimpling technique.
As there is little control of size I make several of several different sizes and then figure the optimum 'focal length' for each size.
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