Experiment 6

A Pinhole Camera

Materials: Large coffee can with plastic lid (the semiclear type). Large dark cloth.

BASIC CAMERA. It’s amazing how simple a camera can be, as you’re about to find out. To make one, punch a hole about the size of a penny in the bottom of the coffee can. Do it in the center. Then cover this hole with a disc of thin cardboard, taping it down around the edges. Now pierce a hole in the disc with a pin, put the plastic lid on top of the can . . . and there’s your camera, ready to go.

SCREEN AND LIGHT SHIELD. The plastic lid is our viewing screen. However for you to be able to see the projected image of what you aim at, the screen has to be shielded from light. For this pur- pose, drape the dark cloth over your head and the camera, the way some photographers do.

A TOPSY-TURVY WORLD. Aim the camera at something bright about 10’ away. Hold the screen a foot or so from the eye. Note that what you see on the screen will be upside down. This is because light travels in straight lines. The light from the top of the object travels through the pinhole and lands on the bottom of the screen. Similarly, light from the bottom of the object strikes the top of the screen.