Reduce, Reuse, Recycle.
One out of three isn’t bad.
Cardboard is a very versatile material, and its seems to be everywhere, just waiting to be reused. This activity is going to turn 4″x4″x18″ carboard containers into pinhole camera. Here is what you’ll need:
- Wax paper
- Aluminum foil
- Cardboard Pieces
- Tape (something opaque, like duct tape is best)
Cut the Cardboard
This project begins with cutting the cardboard. For the St. Petersburg College Earth Day celebration, the pieces are pre-cut. There is a 7″ piece and a 2″ inch piece.
Make the Screen
Take the 2″ piece and open it up as a square again. Cover one end of it with wax paper. This is a good material because it is translucent, but not transparent. Use tape to seal up the ends.
Flip it over and cover the end with aluminum foil. Use tape to seal up the ends. Opaque tape works best because you want to be sure that the only light coming through this is coming through the pinhole that we’ll make later.
Make the Viewer
You will need a place to put your eye. We need the 7″ piece of cardboard for this one. This cardboard had little flaps to be sealed like a box. If we cut triangles out of both sides and fold them inward we can make a viewer big enough for your eye.
Fold the flaps inward until their edges touch. This will make a pyramid-like viewer.
Attach the Screen
Now the 2″ section needs to be attached to the 7″ section. Using opaque tape or wrapping aluminum foil around the area will keep stray light from coming in.
Make a Pinhole
In the center of the aluminum foil end, poke a hole with a pinhead. Try to make it as smooth as possible. Try to keep it small. A small hole works better than a large one. Only one hole is needed.
Take the cardboard camera outside and point it towards something. You will need a lot of light for this to work. You will see an obvious image, that is upside down.
The science behind the pinhole camera is rooted in physics and optics. This is a very primitive yet effective way to capture light and produce images. Our device isn’t really a camera, because nothing is being used to capture the light or record an image. We have simply built the light collection device.
The image that you see is inverted and reversed. When you look through the viewer, the top of your image is at the bottom of what you are actually seeing. The left of your image is at the right of what you are actually seeing. This is a result of the way light is entering the box through the pinhole. Since light travels in straight lines, light from the top of an object goes through the pinhole to the bottom of the screen. Light from bottom goes to the top.