A new type of camera

CONVENTIONAL CAMERAS focus light onto a recording medium to preserve an image as a field of tiny dots. The media have changed over the years from plates of silver to plates of glass to acetate films to charge-coupled devices. The dots, meanwhile, have gone from being grains of chemicals to electronic pixels. But the principle has stayed the same. And moving pictures are simply streams of such images shown in sequence.This arrangement is known as a frame camera. But there is now an alternative, the event camera. Unlike a frame camera, an event camera does not activate the dots simultaneously, using a physical or virtual shutter. Instead, a dot responds only when the nature of the incoming light changes.