The description of a film's photographic response to radiation of various wavelengths. Silver halides, the fundamental photosensitive elements of all photographic emulsions, are sensitive to high-energy radiations. However, they are sensitive only to the ultraviolet, violet, and blue in the visible and near-visible spectrum. Sensitizing dyes are commonly used to extend the sensitivity of an emulsion to the green, red, and near-infrared portions of the spectrum.
(of a photoreceptor) The sensitivity of a photoreceptor at each wavelength in the visible spectrum. For a given wavelength, this is equal to the ratio of the photoreceptor response at that wavelength to its response at the most sensitive wavelength. Different photoreceptor types have different spectral sensitivities.
The relative sensitivity of a particular emulsion to specific bands of the spectrum within the films sensitivity range. Sometimes confused with Color Sensitivity.