MEDIUM TECH: Materials: sewing needle, thin brass shim material, emery paper, measuring loupe, opaque tape, sharpie pen, cardboard. [another source of thin metal is soft drink cans, approximately 0.1 mm thick] 1) cut out a 25 mm square of brass shim and place on cardboard [1 inch] 2) gently push the sewing needle into the brass, but not all the way through 3) sand paper the "bump" on other side of the brass 4) repeat steps 2 & 3 until a very small hole is produced
5) measure the size of the hole with the measuring loupe. You can always make a hole larger, but you cannot make it smaller. 6) blacken brass around the hole and tape onto camera 7) calculate the f-stop and use the camera [f-stop = distance to the film divided by the diameter of the pinhole] NOTES: Step #4. If you go back and forth to BOTH sides, you will actually make a better pinhole. [the thinnest part of the hole will be in the center of the foil instead of off to one face] Step #6. It turns out the Rapid Selenium Toner and Polytoner from Kodak will blacken brass and copper. Just dip into the solution for a few seconds, rinse and dry. No possibility of accidentally covering the whole with dried ink. [worked out with Murray Leshner 4/27/2004] |
