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 are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Suntan and sunburn are familiar effects of over-exposure of the skin to UV, along with higher risk of skin cancer. Living things on dry land would be severely damaged by ultraviolet radiation from the Sun if most of it were not filtered out by the Earth's atmosphere. More-energetic, shorter-wavelength "extreme" UV below 121 nm ionizes air so strongly that it is absorbed before it reaches the ground. Ultraviolet is also responsible for the formation of bone-strengthening vitamin D in most