How to make a pinhole camera with everyday items for safe solar eclipse viewing

TORONTO – If you haven’t been able to secure solar eclipse glasses ahead of the biggest celestial event in years, do not fret.

There are other ways to safely observe the eclipse on Monday, albeit in an indirect way.

Millions of people across a swath of North America, including parts of Eastern and Atlantic Canada, will experience a few minutes of darkness in the middle of the day as the moon passes in front of the sun.

One of the simple ways to observe the phenomenon is with a pinhole camera – more accurately described as a projector – that can be created with items most of us already have at home.

If you’re really pressed for time, even a single sheet of paper and a push pin will do the trick, says Elaina Hyde, director of the Allan I. Carswell Observatory at Toronto’s York University.

“A pinhole camera (is) one of the oldest camera techniques,” she said.

A basic pinhole projector can be made by pushing a pin through a piece of paper or cardboard to create a tiny hole. When you take that paper outside and cast a shadow with it on the ground, the bit of light that passes through the hole projects “a little tiny image of the sun” and allows safe tracking of the eclipse, Hyde said.

“And this will work with nearly anything that you have in your house. You can use a sturdy construction board. You can use paper.”

Another option, she said, is to use a common kitchen utensil.

“If you have a pasta strainer that has circular holes in it, you can take it outside and cast the pasta strainer shadow on the ground,” Hyde said. “As you look at the shadow of a pasta strainer, all of those holes … are actually going be little tiny images of the sun.”

If you’re willing to put in a little bit more effort – and want to engage kids in a fun activity – you can create a pinhole camera out of a cereal box, shoe box or other cardboard box easily held to the eye.

For this project, you will need a piece of white paper, scissors, aluminum foil, a pin and some tape.

According to instructions from NASA and the Canadian Space Agency, cover one of the inner sides of the box with white paper, cut to size – this is what will display a projection of the eclipse.

Cut two square or rectangular holes on the opposite side of the box, one on the left and one on the right. The holes should be at least 10 centimetres apart – one is to view the interior, and the other will be modified to project the eclipse onto the paper inside.

Next, cover one of the holes with aluminum foil, taped into place, and then poke a tiny hole in the foil with a pin. Ensure the box is tightly sealed.

Turning your back to the sun during the eclipse, look through the uncovered hole in the box and position yourself so that light enters the pinhole and the shape of the sun is projected onto the white paper inside the box as the eclipse progresses.

Hyde stressed the importance of never looking at the sun directly during the eclipse without proper eye protection, which must have an ISO-rated solar filter.

“Do not try to use welders’ goggles. Do not use regular sunglasses. Do not stack pairs of regular sunglasses,” she said.

“Anything you’re thinking of doing DIY (to watch the eclipse), it needs to be indirect. There is no way to DIY safely a pair of safe solar glasses.”

This report by The Canadian Press was first published April 5, 2024.