Live Photos - Training Wheels for Action Photographers
Anticipation.
Back in the wee small days of digital photography, I was obsessed with a new camera by Olympus, I think, that let you capture images BEFORE you took the picture. It was my first inkling that digital cameras were not just cameras without film. They could do really cool stuff.
Shooting sports, among other things, is all about anticipation. You have to get yourself in the right spot and trip the shutter at the right time. But what this camera did was continuously capture images as you were framing your shot and then saved 3-5 frames before the one you took. If you were just a little slow to press the shutter, chances were that you would still have 'that' shot in the early images. Yeah, it was a little bit of a cheat, but it was also just a 2mb image in a camera priced at about $2000. It didn't threaten professional sports photographers.
Today, we have that same feature on all our iPhones in the form of Live Photo. This is a little different riff than how Live Photos offers motion eye-candy in the form of loops, bounces and animated GIF's. This is about the same pre-exposure images the can get the smile, the jumping cat, or the bolt of lightning that you weren't quite fast enough to catch.
With Live Photos on, the camera is recording continuously. When you frame your shot, before you decide to trip the shutter, your iPhone is already saving snaps of what it sees. At shutter release, what's saved is the exposure you made and the 1.5 seconds before and after, giving you about a 3 second window from which to choose your favorite frame. One handy way to use it is with little kids, group photos where someone insists on making a goofy face or blinks, and with busy background action so you can choose a frame that's most matches your intent.
When you take a picture with Live Photo turned on, just open the picture in Edit Mode and you'll see the frame selector under the shot. Then choose the best frame to save. You can turn Live Photo off (tap the yellow circles) to lock the picture frame and avoid exporting the 3 second video along with your picture when you share.
You probably don't want to leave Live Photos on all the time because those short videos do take up space and time to edit, but it's a handy option to have when you need some training wheels and are developing your sense of photographer timing.