What is the principle of working of a pin hole camera

Pinhole camera works on the principle that “Light travels in straight lines"Light from the objects enters the camera through the pinhole. It goes to the screen where it forms an inverted and small image. The image has the same colour as the object. If the pinhole is small, the image will be sharp and clear. If the pinhole is large, many images will be formed on the screen instead of a sharp image and final image will be burred. construction:-Step 1 You will need a box, photo paper, thin piece of metal like a can or brass shim, tape, xacto knife, needle, and sand paper. Step 2 The pinhole is like the lens of the camera. Poke a tiny hole in the brass shim with a needle and sand it smooth. Trim the shim so there is a little space around the hole. step 3You can use a shoe box, oat meal box or whatever. The box must be light proof. When the lid is on and the shutter is closed the inside is completely dark. The only light comes through the pinhole. Make sure there are no holes or openings in the box. Seal it and paint it flat black. Cut a small square opening in the box for the pinhole to go in. step 4 Tape the pinhole behind the square opening. I use electrical tape. Center the pinhole in the square. Then make the shutter which is just a flap that covers the pinhole from the outside. It can be made from some more tape. step 5This must be done in complete darkness. You can make a darkroom in a bathroom or closet and use it for developing and changing paper. Tape a piece of photo paper to the inside of the box across from the hole. Put lid on and make sure the shutter is closed. Now you can go out in the light.