This standard establishes the requirements for light sources suitable for use for sensitometric exposure of photographic materials, both black and white and colour. The spectral characteristics of the exposure radiant energy correspond closely to the spectral energy distribution of an average wolfram illumination modified by the spectral transmission of a typical photographic lens (see Table III), excluding infrared rays.
UNI 7238-1973 history
1973UNI 7238-1973 photo. Light source for photosensitive exposure. Simulation of spectral distribution of tungsten illumination