Time-Lapse Photography

time-lapse photography [′tīm ¦laps fə‚täg·rə·fē]

(graphic arts)

Motion picture photography in which a single frame is exposed at regular intervals; when the film is projected at normal speed, the action appears to be speeded up.

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Time-Lapse Photography 

motion-picture photography in which the camera is stopped between the exposure of successive frames; a special type of accelerated-motion photography. Depending on the characteristics of the subject and the purposes of the filming, the intervals between frames may range from approximately 0.2 seconds to several hours or, in exceptional cases, even days. The camera is connected to a special device, such as a timer or electrical relay, that generates pulses for starting the film-transport mechanism and, when necessary, for switching any lighting equipment on and off. When the sequence of frames obtained is subsequently shown with a regular motion-picture projector having the standard frame frequency (much greater than that used during filming), the changes that occurred in the subject during filming appear to be compressed in time (speeded up), which makes them easy to observe.

Time-lapse photography is used in physics, solid-state experimental and applied mechanics (the growth of crystals and the gradual destruction of solids), chemical kinetics (the progress of chemical reactions), cytology and molecular biology (processes at the cellular and subcellular level), and microbiology (the growth and development of microorganisms). It is also used in feature films, especially in scientific feature films, where the technique is particularly effective.

A. L. KARTUZHANSKII and V. G. PELL’