Ultraviolet photography Silicon (from which DSLR sensors are made) can respond to wavelengths between 1100-190 nm. Photography based on visible fluorescence induced by UV radiation uses the same ultraviolet illumination as in reflected UV photography. However, the glass barrier filter used on the lens must now absorb or block all ultraviolet and infrared light and must permit only the "visible" radiation to pass. Visible fluorescence is produced in a suitable subject when the shorter, higher energy ultraviolet wavelengths are absorbed, lose some energy and are emitted as longer, lower energy visible wavelengths. UV induced visible fluorescence photography must take place in a
Ultraviolet communication in butterflies some species this distinction is not seen at all times, and UV patterns may vary visually depending on the position of reflecting light. This can be seen in the common brimstone, where males will exhibit male or female patterns of iridescence with different positions, distances, and angles of light - this is known as the "gynandromorphic" effect. The ultraviolet communication system employed by butterflies is also used an indicator of male sex to other rival males in the butterfly, "Colias eurytheme". In this species, only males are able to reflect ultraviolet light off the dorsal side of their wings, while