In 1997, I bought a set of eleven pin holes ranging in diameter from 0.099 to 0.701 mm from Pinhole Resource, Star Route 15 Box 1355, San Lorenzo NM 88041. They are drilled in thin monel sheets. I don't know if they're still in business. I mounted the smallest one on a Canon body Cap with a 1/4" hole drilled in its center and taped the 0.099 pinhole on the outside. I haven't done much with it and can't locate any photos I may have taken. I'll try again in a few days. BTW, Canon SLR bodies have a small circle with a horizontal line through it. This marks the location of the film (or sensor) plane and is 50 mm from the lens mounting flange. You need this information to determine the optimum hole diameter. The distance from the flange to the surface of the body cap is 6.4 mm, so mounting the pinhole there gives a focal length of 56.4 mm. On Karl's chart this yields an f-stop of about 525 for a 0.1 mm pinhole, close to the green wave length line. David's suggestion (below) is a good one if you're going to make your own pin hole. There was a lot of discussion of this topic on the list in Spring 1997. Roger On 7 Feb 2011, at 11:35 AM, David Dyer-Bennet wrote: > > On Mon, February 7, 2011 09:07, mark@xxxxxxxxxxxxxxxxxxxx wrote: >> Well I have a drill press and tools so what I was planning to do is drill >> the hole directly into the body cap, but don't know if I can find a bit >> that small after hearing the discussions. Taking it into the body cap >> would give a good clean hole that wouldn't tear up every time you threw it >> into a bag like aluminum foil would. Anything paper, ect would be >> destroyed the first time you tossed it in the camera bag. I was hoping >> for something durable enough that it could bounce around, be abused by >> banging into other stuff in a camera bag, and still be totally functional. > > The classic method is to indent a brass shim with a needle, and then sand > off the dent on the back, making a very small hole (less than needle > diameter) with relatively smooth edges (using 1000-grit paper or some > such). > > -- > David Dyer-Bennet, dd-b@xxxxxxxx; http://dd-b.net/ > Snapshots: http://dd-b.net/dd-b/SnapshotAlbum/data/ > Photos: http://dd-b.net/photography/gallery/ > Dragaera: http://dragaera.info >
