Time-lapse photography is a technique whereby the frequency at which film frames are captured (the frame rate) is much more spread out than the frequency used to view the sequence. When played at normal speed, time appears to be moving faster and thus lapsing. For example, an image of a scene may be captured at 1 frame per second, but then played back at 30 frames per second; the result is an apparent 30 times speed increase. In a similar manner, film can also be played at a much lower rate than it was captured at, slowing down an otherwise fast action, as in slow motion or high-speed photography.
Processes that would normally appear subtle and slow to the human eye, e.g. the motion of the sun and stars in the sky or the growth of a plant, become very pronounced. Time-lapse is the extreme version of the cinematography technique of undercranking. Stop motion animation is a comparable technique; a subject that does not actually move, such as a puppet, can repeatedly be moved manually by a small distance and photographed. Then the photographs can be played back as a film at a speed that shows the subject appearing to move.