RADARspeed: Slow-Mo Speed

Turn your iPhone into a radar gun. RADARspeed measures the speed of anything you can film — a sprinter, a pitch, a car, a cyclist, an arrow — using the exact timestamp of every frame in a slow-motion video. HOW IT WORKS Speed is distance divided by time. RADARspeed reads the precise presentation time of each frame, so timing is accurate to a single frame: 4.2 ms at 240 fps. You provide the distance with a quick on-screen calibration, mark the object, and get its speed with an honest ± range. THREE WAYS TO MEASURE • Speed Trap — place two gates on landmarks a known distance apart and mark the frames where the object crosses each one. Works from any camera angle and is the most accurate method. • Side View — drag a line across anything of known length in the object's path, such as a car's wheelbase or a lane marking, then track the object. • Top-Down — place four corners on a rectangle on…