Used in most low and medium priced projectors, these lamps last about 40 hours, with consistent output throughout their life. Although halogens look very white compared to a normal incandescent lamp, they are not as white as metal halide units. Cost of operation: Under $0.50 per hour. Most projectors using halogen lamps carry a spare lamp inside.
(Tungsten-halogen lamp) high pressure lamps containing halogen gases which allow the filaments to operate at higher temperatures and higher efficacies. Halogen lamps use a filament, but since it is sealed in a pressurized capsule containing halogen gas, the lamp provides brighter, whiter light with better color characteristics, longer service life and improved energy efficiency.
The mr-16 type halogen lamp is usually the preferred light source for holograms. This small bulb is common and inexpensive, but requires the standard 12 volt dc housing. An excellent alternative is the PAR 16 lamp, which operates on ordinary line voltage.
