Since the introduction of photography as a reconnaissance tool for the military, there has been a desire to collect photographic images on an around-the-clock basis. A large technology has been developed since World War II to provide the necessary illuminants to produce night photography. Night photography was successfully produced by a large variety of flash bombs, cartridges and illumination flares. These pieces of ordinance emitted the vast quantities of light required to expose film in aerial cameras. They also, however, emitted vast quantities of noise and tended to illuminate the reconnaissance aircraft more efficiently than they illuminated the ground.
Charles W. Haney,
"Low Light Level Photography", Proc. SPIE 0042, Image Intensifiers: Technology, Performance, Requirements, and Applications, (1 March 1974); doi: 10.1117/12.953874; https://doi.org/10.1117/12.953874