Understand that your phone isn't going to do much
To get pictures during the eclipse, most people will reflexively whip out their smartphone like it’s selfie time at the pool party. But Gilman says even the best Instagrammers in the world won’t be able to get good images with their phones.
“The typical lens on a phone is about 28mm,” he says. “And you’re going to need a longer lens to photograph this thing. Typically the camera (on a phone) is at a fixed length, and when you zoom in you’re just cropping pixels, not really zooming in. Your picture is just going to be a teeny blob off in the middle of nowhere and not properly developed.”
Basically, since the moon is 238,000ish miles from the Earth and the sun is almost 93 million miles beyond that, using your fingers to zoom in reeeeeeally far is a great way to take the sort of shot where you have to explain to someone, pointing to a distorted blob: “See that right there? That’s the moon.”