Incandescent Lighting
Incandescent Lights are the original artificial kind of electric lights that were invented by Thomas Edison. The most common type is a bulb of glass that holds a vacuum. A tungsten filament is heated by passing an electric current through it. The filament heats to about 2550 degrees Celsius (roughly 4600 degrees Fahrenheit) and it emits light to shed its heat. The presence of an atmosphere would cause too much heat loss by conduction and an atmosphere containing an oxidizer such as oxygen would cause the filament to burn up very quickly. Though incandenscent lighting has been used continuously since its introduction, it is quickly being replaced by more efficient technologies.There are three reasons why incandescent is not a good choice for studio lighting. First, because lights of this type are not very efficient, much of the power applied to them is given off as heat. Secondly, the light emitted by tungsten is red-shifted, much of it being invisible infra-read. This means that color is deficient at the blue-end of the visible spectrum. Halogen lamps give off more blue but they are notorious for the heat they give off and they have to operate at high voltages. Their bulbs are easily destroyed if they are mishandled as even finger prints left on their surfaces can collect enough heat to cause the bulb to shatter during operation. Finally, the intensity of an incandescent emitter is slow to change. This means that lighting controls are very sluggish. All of these drawbacks combine to make incandescent lighting a poor choice for today's high-tech video studio.