photochronograph: Meaning and Definition of

pho•to•chron•o•graph

1. a device formerly used for taking a series of instantaneous photographs of a rapidly moving object.
2. a picture taken by such a device.
3. a chronograph in which the tracing or record is made by a pencil of light on a sensitized surface.
4. an instrument for measuring small intervals of time by the photographic trace of a pencil of light.