Thursday, April 20, 2006
Mounting a homebrew pinhole in a SLR body cap
I've recently been selling pinholes on Ebay, and a few people have asked about mounting them into a SLR body cap. In some ways, this is the easiest way to get into pinhole shooting. Homebrew cameras designed for roll film (120, 35mm) are finicky to get right in terms of light-tightness, film advance/counting, loading mechanism, shutter design, etc. I should know - I was up late last night working on my first homebrew camera, based on the matchbox design, but made of sheet metal (stay tuned for an upcoming post). With a 35mm SLR all you need is a pinhole and a body cap to modify.
Basically all that is needed is to drill a hole through the center of the plastic cap and tape the pinhole into the inside of the cap, centered on the hole. I like to do a slightly more careful job: drill a small hole through the center of the cap from the inside, and then use a large drill bit to chamfer the hole from the outside. If you're a woodworker a countersink bit is excellent for this. This produces a cone shaped hole in the cap that prevents vignetting at wide angles. Click on the photo above for a visual guide.
Then simply tape the pinhole over the cap hole with black tape. Use either electrical tape, or better still black cloth hockey tape (how can you tell I'm Canadian?), which is non reflective. Viola, you are ready to go create your pinhole masterpiece.
If you need a pinhole, search for "custom pinhole" on Ebay and look for my auctions (my Ebay handle is "gabriel531"). I can make you an excellent pinhole that is the best size for your focal length.
Posted by Dennis Venema at 9:51 AM