One Tech Tip: Using your smartphone to capture the August total solar eclipse over Europe

Millions of people will get to experience — and film or photograph — a rare total solar eclipse set to sweep over parts of Europe next week.

The event is expected to boost tourism to Spain as eclipse enthusiasts flock to a swath of the country's north that will be in the path of total darkness on Aug. 12. Parts of Greenland, western Iceland and a corner of Portugal are also in the shadow's path.

Eclipse chasers may also join eclipse cruises in the north Atlantic. Much of the rest of the northern hemisphere will see a partial eclipse.

Interest surged for 2024 's total eclipse over North America, with many people using their smartphones to document it. This year's event is expected to be no different.

But an eclipse poses unique challenges for photos, such as drastic changes in lighting. Here are pointers on how smartphone shooters can get the best shot.

Location is key. If you're travelling to view the eclipse, you’ll want to be as close as possible to the path of totality.

The European Space Agency has posted a map of Spain on its website showing how many minutes of totality there will be for different parts of the country.

For more detail, eclipse expert Xavier Jubier’s website overlays the eclipse’s path on Google Maps, which allows zooming down to the street level.

Be aware that for most places in Europe the eclipse won’t happen until close to sunset, and the sun and moon will get closer to the horizon as it continues. So try to find a high point with clear views of the western horizon.

Weather conditions can change so consult forecast and cloud coverage apps like Astrospheric ahead of time to find locations with clearer skies.

The American Astronomical Society has a list of recommended iOS and Android apps, which can do helpful things like play an audio countdown to the moment of totality, and simulate how the eclipse will look from your position so you can set up a shot in advance.

A digital SLR camera is your best bet for dramatic close-up photos of the moon passing in front of the sun.

But you can still take a good photo with a smartphone.

Be aware that iPhones and Android devices aren't really designed for photographing objects in the sky. Their lenses are great for wide-angle shots but not so good for capturing close-up detail from faraway.

But newer phones have sophisticated sensors, multiple lenses and image stabilization software that give you a better chance. Many also have exposure controls, so you can darken or lighten the image amid tricky eclipse lighting.

“The main challenge with using smartphone cameras for astronomical photography is that they tend to overexpose bright objects” such as the moon or the inner solar corona, the American Astronomical Society says in its online guide to photographing eclipses. At the same time, smartphones have trouble focusing on dim objects, which is “almost everything else in the sky,” the group says.

“Zooming in to make the subject bigger often helps.”

Just don’t use flash. It won't be effective and can spoil the moment for anyone around you whose eyes have adapted to darkness.

And don't just focus on the sky. Look at the scene around you. As the moon passes in front of the sun, the landscape will be “bathed in eerie lighting and shadows," NASA says in photo tips it posted for the 2024 eclipse.

“As light filters through the overlapping leaves of trees, it creates natural pinholes that project miniature eclipse replicas on the ground,” NASA says. “Anywhere you can point your camera can yield exceptional imagery, so be sure to compose some wide-angle photos that can capture your eclipse experience.”

If you're photographing the sun during the partial phases of the eclipse, the lens must be protected by a special-purpose solar filter, said Antonio Garcia Fernandez of Volunteer Astronomy Observers of Spain, a group of astronomers and professors that set up a website, Eclipse Seguro , to share safety information ahead of this year's eclipse.

The group recommends the Solar Snap filter, the only one designed for smartphones that's certified to the international ISO 12312-2 standard for solar filters.

Or just use a pair of eclipse glasses, which are more widely available, over the lens.

“This makeshift method is a great low-cost DIY alternative and was widely and successfully practiced by millions of observers during the recent 2023 and 2024 solar eclipses in the Americas,” Garcia Fernandez said.

Don't forget to also wear a pair of eclipse glasses if you're looking at the sun while lining up a shot.

Watch out for fake glasses. Eclipse Seguro and the American Astronomical Society list models that they've vetted for compliance with the ISO standard.

“Online marketplaces are currently flooded with uncertified or counterfeit glasses” with fake ISO labels, which can cause permanent blind spots in seconds, Garcia Fernandez said.

Use a tripod for steady shots or if you plan to shoot for an extended time. To keep your gear from overheating as you wait for the big moment, grab a white towel to cover it up.

To prevent jostling your device when hitting the shutter, use a smartwatch shutter button app or set a timer to take the photo.

It’s tempting to make a TikTok or Instagram-friendly eclipse video. Perhaps you want a selfie video, narrating into the camera while the cosmic ballet between sun and moon plays out over your shoulder.

While you might think your vision isn’t at risk because you’re not looking at the sun, your phone’s screen could reflect harmful ultraviolet light, eye experts have warned .

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