This pair of intensified cameras measure the total radiative output of the SRC during entry in the 400 - 900 nm band.
The INT instrument consists of four cameras, two on both sides of the aircraft, consist of a 50 mm f2.8 Nikon lens, an XX1332 image intensifier with large 48 mm photocathode, and a Sony handycam camcorder (recording of video output on Hi-8 tape in NTSC format - 640 x 480 pixels). The lens can be equipped with a low-dispersion grating to generate 1st and higher order spectra, each containing a fraction of the light. This facilitates the measurement of luminosity when the zero order image saturates.