FinePix IS Pro filters are required to photograph in IR or UV wavelengths. Infrared filters are readily available at low cost from many sources, but ultraviolet filters – and suitable lenses – can be expensive. Photography in infrared and ultraviolet poses its own special challenges regarding exposure and – above all – focusing a SLR camera. By definition, these forms of light are invisible to the human eye. The IS Pro includes a Live View mode that relays what the sensor sees as live video to the LCD screen (and, optionally, via USB to a computer running appropriate software). Some lenses have separate
Photoelectric effect with an induction coil between zinc or cadmium terminals, the light from which is very rich in ultra-violet rays. Sunlight is not rich in ultra-violet rays, as these have been absorbed by the atmosphere, and it does not produce nearly so large an effect as the arc-light. Many substances besides metals discharge negative electricity under the action of ultraviolet light: lists of these substances will be found in papers by G. C. Schmidt and O. Knoblauch. In 1839, Alexandre Edmond Becquerel discovered the photovoltaic effect while studying the effect of light on electrolytic cells. Though not equivalent to the photoelectric