Here is a very simple home version of a DIY "camera obscura" ("dark chamber") - the first kind of cameras, first created over two thousand years ago (!).
What do we need:
- Two empty rolls, one of them a bit narrower than the other so that it can fit into it (we used a toilet paper roll and a paper towel roll).
- A scrap of aluminum foil.
- A scrap of waxed paper, or another partly transparent paper. We used the thin paper that separates between transparencies in their box.
- A pencil, scissors, scotch tape and a toothpick.
Check the rolls to see that one can fit into the other easily enough to move backward and forward, but not so loosely as to fall off. The rolls we chose fit perfectly, so we cut the paper towel roll to shorten it. We left it a bit longer than the other roll to easily tell them apart.
If you can't find two rolls that fit as required, simply adjust one of them: cut along it as shown in the image above (1), and tape the edges (2) so that they fit the required width.
Start with the wider roll. take the aluminum foil scrap (1), carefully wrap one end of the roll and fasten it to the roll using scotch tape (make sure that no light can come in from the sides - 2). Make a tiny hole with the toothpick in the center of the aluminum circle (3).
Now wrap the waxed paper around one end of the narrower roll. To avoid creases, put the roll on the paper and mark its contour on it (1). Now cut "sun rays" around the circle (2), put the circle in its place on the roll (3), and fold and tape each "sun ray" until they're all in place.
Insert the narrow roll (wrapped with waxed paper) into the wide roll (wrapped with aluminum foil), and get out to the sun. Hold the open end (the one that's not covered with anything) close to your eye, so that no light can penetrate between your eye and the roll (if you're wearing glasses you might want to cover the openings with your hands). Find a well-lit object, such as a tree. Adjust the focus by moving the inner roll slightly inward or outward to find the sharpest image you can get. What do you see? Note: the image looks different through the camera! here's a hint: in the first image above, you see treetops as seen through the camera. Where is the sky in this image?... :-)
P.S. This is a real camera, which means that the photos can be developed, but it takes a very long exposure - leaving the camera motionless for hours - and special equipment. We settled for experimenting, and had lots of fun... :-)