Ultraviolet range

The ultraviolet range of the electromagnetic spectrum extends between the wavelength range from 10-400 nm. Especially distinguishable ranges are medium ultraviolet UVA (280-315 nm) and high wavelength ultraviolet UVB (315-400 nm), which are the ranges that can be applied to the study of works of art. There are many sources of ultraviolet radiation, including the sun, but when photographing works of art special artificial lighting sources are used (similar to the known black-lights) and  the process takes place in the darkroom.