How to make a pinhole viewer for eclipse 2017

So, you’re excited to make an event out of watching the solar eclipse, maybe with family and friends. But, of course, you want to view it as safely as possible. Unfortunately, the one rule of enjoying an eclipse is often the first rule that gets thrown aside.

“During an eclipse, people want to look at the sun, and that is obviously dangerous,” Dr. Lawrence “Doc” Pilgrim said. “You don’t look directly at the sun. What you look at is the sun’s image.”

Pilgrim said there are more than a few ways to safely watch an eclipse. You don’t have to buy a telescope, but you can. Your options range from a primitive box to a more costly, high-tech solution.

On the low-tech end, he suggested making a pinhole camera from a simple box. A person can simply cut a slot from one side of a box and then line the slot with tinfoil, which you then poke a hole through.

“The hole acts like a lens that allows sunlight to shine through the box onto the inside of the box,” he said.

Don’t forget to tape a piece of paper to the inside of the box where the light falls, and maybe cut another hole to look through.

“It’s just a primitive device that allows you to project an image of the sun so you can see it against a relatively dark background,” Pilgrim said. “That’s why you have it in a box.”

To achieve an even better result, Pilgrim said, a telescope can be used in much the same way as a pinhole camera.

“Depending on how big the telescope is, it will gather hundreds of times more light and you project an image with the telescope the same way, only it’s bigger and brighter, that’s all,” he said.

The trick, Pilgrim said, is to aim the larger end of the telescope at the sun. Then place your back to the sun and use the shadow to guide where it should point.

He advises never looking through the telescope, but rather at the image projected on a background.

And never look directly at the eclipse, except during totality. If there’s even a tiny bit of sun exposed, the light could damage your eyes. If you have access to a welder’s helmet, Pilgrim says that will work too.

Whether it’s with a pinhole viewer, a welder’s helmet, a telescope or those cool eclipse shades, think safety first for your eclipse watching.

The eclipse begins Aug. 21 at 11:40 a.m. with totality lasting for two minutes and 38 seconds.