Why photos taken under discharge lamps often look blue-green?
The problem here is the fact that film and human eyes have different spectral response. Human eyes are quite sensitive to the short wave end of the red range of the visible spectrum, but not to the long wave end. Most color film responds about the same to shorter and longer red wavelengths. Most of the red light from fluorescent lamps, metal halide lamps, sodium lamps, and phosphored mercury lamps is of shorter red wavelengths. These lamps do not emit much of the longer red wavelengths. This maximizes red sensation by the eye for a given amount of actual light. Producing less-visible longer red wavelengths detracts from maximizing luminous efficacy of the lamp, so this is minimized. Therefore, lamps make a surplus of red wavelengths to which the eye is more sensitive than film is, and a shortage of the red wavelengths to which film is more sensitive than human eyes. This results in the film seeing red less than human eyes do, and this makes photos look blue-greenish. Arc and glow disch
