Ultraviolet photography sensor will pick up reflected infrared radiation as well as ultraviolet, which may obscure the details that would be resolved by ultraviolet alone. Most types of glass will allow longwave UV to pass, but absorb all the other UV wavelengths, usually from about 350 nm and below. For UV photography it is necessary to use specially developed lenses having elements made from fused quartz or quartz and fluorite. Lenses based purely on quartz show a distinct focus shift between visible and UV light, whereas the fluorite/quartz lenses can be fully corrected between visible and ultraviolet light without focus shift. Examples
Photovoltaic effect Photovoltaic effect The photovoltaic effect is the creation of voltage and electric current in a material upon exposure to light and is a physical and chemical phenomenon. The photovoltaic effect is closely related to the photoelectric effect. In either case, light is absorbed, causing excitation of an electron or other charge carrier to a higher-energy state. The main distinction is that the term "photoelectric effect" is now usually used when the electron is ejected out of the material (usually into a vacuum) and "photovoltaic effect" used when the excited charge carrier is still contained within the material. In either case,