How to safely watch and photograph the total solar eclipse

On April 8, the moon will pass directly between Earth and the sun, creating a total solar eclipse across much of the United States, Mexico, and Canada.

Although total solar eclipses occur somewhere in the world every 18 months or so, this one is unusual because tens of millions of people in North America will likely witness it, from Mazatlan in Mexico to Newfoundland in Canada.

It's a huge communal experience," says Meg Thacher, a senior lab instructor in the astronomy department at Smith College in Massachusetts. A total solar eclipse is the Super Bowl of astronomy." Here's how to safely watch-and photograph-the natural phenomenon.

Fail to prepare, prepare to fail

It pays to have a plan of action for the day.

Before you decide on a spot to watch the eclipse, whether it's in your own backyard, in a national park, or at a viewing party, it's worth checking the weather forecast to see how likely clouds are to spoil the show. Currently the majority of the eclipse's path of totality-areas where onlookers will see a full eclipse, as opposed to a partial one-is forecast to have some degree of cloud cover.

However, even if visibility turns out to be poor, you still have options. NASA and the National Science Foundation are broadcasting livestreams, and many eclipse viewing parties will broadcast unobstructed views as part of their festivities. The American Astronomical Society has a state-by-state list to help you find your nearest event.

Safety first

You need proper eye protection to look at the eclipse, because the sun's light can cause long-term damage to your vision. Be sure to purchase either specially made eclipse glasses or handheld solar viewers. Glasses might be the best option if you plan to take photos, as they'll keep your hands free. Eclipse glasses are thousands of times darker than regular sunglasses and contain a polymer designed to filter out harmful light.

You should also make sure any cameras, binoculars, or telescopes through which you plan to look at the sun have been fitted with a solar filter. You don't need to double up and wear eclipse glasses if you already have a solar filter, though.

Once the moon fully obscures the sun, it's safe to remove your eye protection for the duration of the totality, which is projected to last around four minutes during this eclipse.

A proper camera is your best bet ...

Photographing an eclipse is pretty simple, says Randall Benton, a professional photographer who has been capturing them since 1979. Although cameras have changed vastly since then, the fundamentals remain the same. (If you plan to use your phone to take photos, skip to the next section.)

He recommends fixing a DSLR or mirrorless camera (equipped with a solar filter to protect both your eyes and the camera itself) to a tripod. A short exposure, which is designed to capture movement, is more likely to capture the details of the sun's corona-the plasma surrounding it. A longer exposure, which keeps certain elements of pictures in focus while blurring others, is likely to stretch the corona further out. The exposure you choose will depend on the kind of shot you'd like to capture.

Before the eclipse begins, take the time to focus the camera exactly where you want the sun and moon to appear in your shot, and turn off any autofocus function. While some mounts come with an automated tracking feature that will follow the eclipse's progression, others will require you to move your camera yourself, so make sure you're familiar with the mount you've got to prevent the eclipse from drifting out of your frame.

Then, when there's just a sliver of sun left and it's a few seconds away from disappearing, take the filter off the camera lens," Benton says. At the very last moment, there's a phenomenon called the diamond ring effect, when the last speck of visible sunlight resembles a ring-that's a great dramatic photo. Once the sunlight reappears, it's time to put the filter back on."

... but smartphones work too

Despite the rapid advances in smartphone cameras over the past decade or so, they can't really rival DSLR or mirrorless cameras when it comes to capturing an eclipse.

Their short lenses means the sun will appear very small, which doesn't tend to produce great photographs. That said, you can still capture the best photo possible by cutting out the plastic lens from a pair of spare eclipse glasses, taping it over your phone's camera lens (or lenses), and securing the device in a tripod (or propping it up against a cup).

Don't try to hold the phone, and use your phone's shutter delay to decrease vibrations, says Gordon Telepun, an amateur enthusiast who has been photographing eclipses since 2001 and has advised NASA on how to capture them. During totality, take the [eclipse glasses] filter off and take wide-angle shots of the corona in the sky and the landscape," he says. Automatic mode will work fine."

Something smartphones are great at capturing is video of the moment the moon glides over the sun, says Benton: That transition from daylight to nighttime is dramatic, and smartphones can handle that pretty well."

Don't be afraid to get creative

During the eclipse, there are plenty of other things to photograph besides the sun and moon. Foliage will create a natural version of a pinhole viewer, casting thousands of crescent images of the sun dancing around in the shade as the light streams through the trees.

Another natural phenomena is shadow bands-flickering gray ripples that appear on light-colored surfaces like sheets or the sides of houses within a few minutes of totality. It's almost like a stroboscopic effect," Benton says, referring to the visual effect that makes objects appear as though they are moving more slowly than they actually are. Videos of that could be interesting."

Take pictures of the faces of the people around you, too," he adds. Twenty years from now, your photo of the eclipse is going to be pretty much the same as anyone else's. These other pictures are going to be a little more powerful in reminding you what your day was like."

Take a moment to look around

Finally, when you're looking up at the moon covering the sun during totality, let yourself enjoy the moment free from your technology. The next eclipse the US can expect to experience on this scale is in August 2044-so try hard to stay present.

During totality, if you're really concentrating on getting your photo, at some point let go of everything. Turn around-take a look with your eyes," says Benton. Whatever you're seeing in the viewfinder or on the screen, it isn't the same thing as seeing it with your own eyes. And it will change your life."