Ultra-fast cinematography - Electronic cameras

In order to break down the movements of objects too fast to be captured by the eye, optical cinematography has since its origins [1] taken advantage of the three dimensions contained in each image (two dimensions of space and one of intensity). The "time base" provided by the regular succession of images makes it possible to locate the evolution of an object at different moments in time, and to measure its speed, or even its acceleration; if it deforms, the speed of deformation can be measured. Transposed to an industrial or laboratory environment, this technique can also be used for timing and event synchronization measurements. When combined with spectral information, the light intensity dimension can also provide access to the temperature evolution of observed objects.

In the 1950s, analysis times ranging from the millisecond to the microsecond range became accessible for the most sophisticated specific equipment of the time. Many industrial applications correspond to this time range.

In the 1960s, these optical cameras gradually reached their ultimate resolution limits. They then gave way to electronic cameras, which were temporally more resolving, implementing double photon-electron and then electron-photon conversion in an electron tube known as an "image converter". The increased speed brought about by electronic manipulation of the intermediate image gives access to the microsecond (10 ^-6 s) to picosecond (10 ^-12 s) range for standard cameras, opening up a particularly vast field of applications at laboratory level.

The most powerful cameras currently achieve a time resolution of around a few hundred femtoseconds (1 femtosecond = 10 ^-15 s) in so-called "slit scan" mode, which is still two to three orders of magnitude above the shortest light pulses currently produced.