The iPhone 5s introduces a new Slo-Mo camera mode, in which you can create videos that seamlessly slide from normal video to super-smooth slow-motion action and back again. That smooth motion happens because in Slo-Mo mode, the iPhone 5s is shooting video at 120 frames per second (instead of the usual 30), so when it’s running at a quarter-speed, it’s still running at the same frame rate as regular video. There’s no stutter of repeated video frames that you’d see in a fake slow-motion effect.
