Here’s a really cool DIY on how to make a pinhole camera with your digital SLR camera.
Do you have a digital SLR camera, some black construction paper, aluminum foil, a rubber band, and tape? Great, let’s make a digital pinhole camera!
The pinhole camera is the simplest type of camera. It has no lens, only a teeny-tiny hole of an iris. This pinhole ensures that the light which reaches any position on the exposure surface originated from a single direction; as the hole diameter approaches zero, the possible light source for a point on the exposure surface becomes an increasingly narrow cone, approaching a straight line.