photochronograph

== English == === Etymology === From photo- +‎ chronograph. === Noun === photochronograph (plural photochronographs) (physics) An instrument for recording very short intervals of time. The record is made by the power of a magnetic field, due to an electric signaling current, to turn the plane of polarization of light. A flash, coinciding in time and duration with the signal, is thus produced and is photographed on a moving plate. (astronomy) An instrument for the photographic recording of star transits. === Anagrams === chronophotograph