Make a Box Pinhole Projector to Safely Watch a Solar Eclipse
A simple and safe way to watch a solar eclipse is with a box pinhole projector. It is easy to make from a cardboard box and ordinary household items.
Next Annular Solar Eclipse: Sun, Jun 21, 2020 … See animation
Project the Sun
Never look directly at the Sun without proper eye protection. You can seriously hurt your eyes and even go blind.
Projector Using a Box
This type of pinhole projector works on the same principle as a basic pinhole projector. However, the box makes this projector much sturdier and easier to set on a surface. And it only requires a few extra items to construct.
- a long cardboard box or tube
- duct tape
- aluminum foil
- a pin or a thumbtack
- a sharp knife or paper cutter
- a sheet of white paper
What to Do:
- Cut a rectangular hole at the end of the box. You can tape 2 boxes together to make a long box. The longer the box, the larger the projected image.
- Using the scissors, cut out a piece of the aluminum foil slightly larger than the rectangular hole. Make sure the foil is completely flat and not crinkled.
- Tape the foil over the rectangular hole in the box.
- Use the pin to poke a tiny hole in the center of the foil.
- Tape the sheet of paper on the inside of the other end of the box.
- Stand with your back toward the Sun. Place the box over your head with the pinhole towards the Sun. Adjust your position until you see a small projection, a reversed image, of the eclipsed Sun on the paper inside the box.
Using a Tube?
If you are using a long tube or taping 2 tubes together, cut the end of the tubes and tape the foil with a pinhole on 1 end. On the other end, tape a piece of white paper over the end of the tube. This will act as the screen. Close to this end, cut a rectangular hole using the knife. This will be your viewing window.
With your back toward the Sun, point the end with the foil toward the Sun, angling the tube along the Sun's rays. Look into the tube through the viewing window until you see a reversed image of the eclipsed Sun on the screen.
- Never look at the Sun directly without protective eye gear. Even sunglasses cannot protect your eyes from the damage the Sun's rays can do to them.
- Always keep your back toward the Sun while looking at a pinhole projection.
- Do not look at the Sun through the pinhole.
No Good for Planet Transits
Unfortunately, for planet transits like the Mercury Transit on November 11–12, 2019, Mercury is too small and too far away to be projected in this manner. However, a projector made from binoculars or a telescope can work.