How to Build a DIY Solar Eclipse Pinhole Projector 2021


An eclipse is an amazing event well worth seeing. A solar eclipse occurs when the moon passes between the earth and the sun, partially or totally blocking the sun's light. It isn't safe to view a solar eclipse with the naked eye, but you can buy eclipse glasses or, if you have a few handy items about the house, you can create an easy and inexpensive alternative called a pinhole projector.

How a Pinhole Projector Works

A pinhole projector works like a camera. Light passes through the pinhole (like the lens in a camera) to project a reverse image on the surface opposite the pinhole (like the film in a camera). Because the pinhole focuses all the light through a small opening, the image you see is small but crisp. This process may sound technical, but the projector is easy to make. Here's how.

Create Your Pinhole Projector

To make your pinhole projector, you need the following supplies:

Cereal boxA sheet of white paper Aluminum foil Scissors TapePencil or penNail, pin, or thumbtack

Using the scissors, cut two square openings at the top of the cereal box.

Place the cereal box on the white paper.

Using the pen or pencil, trace around the bottom of the cereal box on the paper.

Using the scissors, cut the shape you just traced out of the paper.

Place the cut-out paper inside the box, pushing it down so that it lies flat at the bottom of the box. If necessary, tape the paper to the inside bottom of the box.

Cut a piece of aluminum foil so that it's slightly larger than one of the squares you cut out of the cereal box. Then, place the foil over that square, and tape it down to secure it to the box.

For the sharpest image, try to keep the foil as smooth as possible.

Using the nail, pin, or thumbtack, poke a small hole in the aluminum foil. Make the hole as round and even as possible.

Use Your Projector to View the Eclipse

You have your pinhole projector. Now, you're ready to view that eclipse.

Never look directly at the sun during a solar eclipse, even if you're wearing sunglasses or looking through tinted glass. Doing so can damage your eyes or cause blindness. The only way to view a solar eclipse safely is to filter the sun's rays or project them onto a surface.

Stand with your back to the sun.

Holding your projector downward, place your eye to the open square you cut at the top of the cereal box.

Adjust the box or your position until you see the eclipsing sun projected onto the white paper at the bottom of the box.

When the eclipse begins, you'll see a shadow move across the circle. That's the moon moving across the face of the sun. The moon is smaller than the sun, so it can't completely cover it. Therefore, when the eclipse reaches its peak, you'll still see a thin circle of light, called a penumbra, around the shadow.

Always keep your back to the sun.

Wondering when the next solar eclipse will be visible where you live? Check out the National Aeronautics and Space Administration (NASA) solar eclipse website.