This camera made out of cardboard will appromixate how a camera works and teach you about a real camera's inner workings.
In one end of a cardboard box, cut a hole about 1 1/2 inches in diameter.
Now remove the cover and paint the inside of the box black.
Next, cover the hole with a smooth piece of tinfoil, pasting it very carefully on the inside or outside of the box as shown.
Now, very carefully, stick an ordinary pin through the tinfoil, making sure that the hole is clean and round, just the size of the thickness of the pin.
Now take a piece of cardboard the size of the other end of the box and cut out a large square so that the remaining board is a picture frame.
Next, paste tracing paper over this opening and you have the other end of the camera.
Now turn the pinhole toward some bright light or a brightly sunlit window and over the piece of tracing paper which you just pasted on the frame, up and down inside the box until a light image appears on the paper.
Mark this point on the inside of the box and cut off the remainder of the box, fastening the tracing paper 'end' that you made at this point. You now have a pinhole camera.