One of the more interesting advancements in iPhone photography in the last few years has been Live Photos. If you haven’t played around with them before, the sensor actually captures a few seconds of video on either side of the photo. Up until recently, the fun party trick was to hold your finger down on the photo and you could see the tiny video. While enjoyable, you couldn’t do anything else with Live Photos.
Back then the photo was a single hi-resolution JPG with a video sidecar file. But with the new High Efficiency Image Format (HEIF/HEIC) things are getting a lot more interesting.