Step 1: Cut a hole in the box. Use a knife, and make it 1 square inch. For a metal container, drill a hole with a large bit.
Step 2: Cut a 2-inch square out of the soda can. Poke a single hole in the center with the pin.
Step 3: Make the box light-tight, meaning light can’t enter the box from the outside or bounce around once inside. You can do this by covering the seams of the box in electrical tape. For a better camera, cover the interior of the box in black construction paper, but be sure not to cover up the pinhole. NOTE: Spray paint works well here, too. A plastic lid also needs to be opaque.
Step 4: Tape the metal piece over the hole in the box. Place a piece of electrical tape over the pinhole. This is your shutter.
Step 5: In a completely dark room, tape your photo paper to the inside of the box, light sensitive side up. (Lick your fingertip and touch the paper’s edge; the sensitive side should be a little sticky.) In a round camera, the paper will stay in place easily as it hugs the curved sides. If you have a shoebox-type camera, tape the corners of the paper so it fits securely inside the camera
Step 6: Test whether your camera is truly light-tight by taking the camera outside during the daytime with the shutter closed for a few minutes. If the photo paper isn’t pure white after you've put the paper in the chemical developer, it’s been exposed to light.
Step 7: When you’re ready to take a photo, open the shutter and wait. Breslin suggests conducting some exposure tests: “Try a one-minute exposure. If the paper negative is overexposed (too much black), try 30 seconds. If it is underexposed (too much white paper where there should be stuff to see) then try two minutes. Always half or double the time that didn't work last time, and take notes.”
- Work outdoors—bright, sunny days are optimal for taking pinhole photos. Always position the sun behind the camera.
- Don't try to hold your camera during the long exposure. Put it on a flat surface, but weigh it down with something heavy so the wind doesn’t take it away.
- If you think the lid might not be light-tight, place the camera upside down.