I write about using pinhole cameras with my students in my book Why Don’t Things Fall Up? and include instructions for making one in the book. I also included instructions in Mr Shaha’s Recipes for Wonder. This (rather rough and ready) video shows how to make one. See below for written instructions:
You will need:
1 Pringles or similar crisp tube (wiped out and made clean)
Duct tape or aluminium (tin) foil
Scissors or a bread knife
12 cm by 12 cm piece of greaseproof paper (preferably white, not brown), or tracing paper
Drawing pin or safety pin
Magnifying lens or pair of spectacles (optional)
1. Use the drawing pin to make a hole in the middle of the unopened end of the crisp tube.
2. Use the ruler and pen to draw a line around the tube which is 5 cm from unopened end of the tube.
3. Use the scissors or bread knife to carefully cut the tube along this line so that you are left with two tubes, one short, one longer.
4. Hold the square of greaseproof or tracing paper over the open end of the small tube and put the plastic lid over it so that it clamps the paper in place, completely covering the hole.
5. Fold down the edges of the paper sticking out from under the lid, and use the sellotape to stick these edges onto the tube so that the paper is taut under the lid.
6. Remove the lid.
7. Use the sellotape to rejoin the two tubes where you cut them, so that the paper screen is now inside the crisp tube.
8. Wind duct tape around the whole length of the tube. If you don’t have duct tape, you can wrap a sheet of tin foil around the whole tube and use sellotape to secure it firmly in place. This is so that no light can get in through the sides the tube.
9. Look through the open end of the tube while pointing the end with the pinhole out of a window.
Cupping your hands around the tube when it’s held against your eye will help keep out stray light, and you are more likely to see something interesting if it is bright outside and you are in an unlit room.
If you have a magnifying glass or other type of lens, try putting that in front of the pinhole to see how it might change the image you see.