For a few minutes on August 21, everyone in North America will be united in a solitary, awe-inspiring event: A total eclipse of the sun. Americans of all ages are expected to join by the millions to watch the sky grow dark in midday and then slowly brighten again.
People in the U.S. will be able to see at least part of the eclipse. Portions of 14 states are in the path of totality, the brief phase of the eclipse when the moon is totally blocking the sun.
The last time anyone saw a total solar eclipse in the United States was on February 26, 1979. It has been even longer — 99 years — since a total solar eclipse crossed the country from the Pacific to the Atlantic. But it’s happening again and one thing about this eclipse will be very different than those in years past: smartphones!
In addition to professional photographers, millions of ordinary people are expected to use smartphones and digital cameras to photograph this eclipse.
To get some tips on photographing eclipses, CNN spoke with Fred Espenak, a retired NASA astrophysicist and photographer.
Q: Is it really worth trying to take a picture of the eclipse with a smartphone?
A: During the partial phases, the cellphone won’t do you any good unless you can put it up to somebody’s telescope that has a solar filter on the telescope. But if you go under a shade tree, all the little patches of sunlight will be crescent shaped and that can easily be photographed with a cellphone. Anything with a bunch of little holes will project crescent images on the ground.
Q: Is it worth trying to take photos from areas where you will only see a partial eclipse?
A: Sure. If you can only take one look, then try to time it for the period when the eclipse is at a maximum so you’ll see the largest fraction of the sun covered by the moon.
On his website, Espenak gives detailed tips for using a DSLR camera to photograph the eclipse. He cautions you’ll need a special solar filter and some patience — eclipses take awhile.
NASA has a cheat sheet on taking images of the eclipse with your smartphone. You do need to do some homework or you’ll end up with a fuzzy red blob.
— Buy a solar filter or use your eclipse glasses (NOT regular sunglasses) as a solar filter to cover your smartphone lens during the early part of the eclipse.
— Take the filter off during totality.
— Use a tripod to keep your camera stable.
— If you want to take pictures of the stuff going on around you during the eclipse, use a low…