Hydrargyrum Medium-Arc Iodide, frequently called just HMI is a mercury-halide discharge short arc lamp with a color temperature of approximately 5600K. The name is derived from Hydrargyrum, an archaic term for mercury while Iodide indicates that iodine is the halogen used to form the active compound.
History
In the late 1960s German television producers sought out lamp developer Osram to create a less expensive replacement for incandescent lights for the film industry. Osram developed and began producing HMI bulbs at their request.
Today's use
Multi-kilowatt HMI lights are used in the film industry because of their optical spectrum, as well as their efficiency. The light they emit is close to that of noontime sunlight.
Using proper insulation techniques these lights can be used for underwater lighting.
Efficiency
HMI bulbs are commonly two to four times as efficient in generating light than are their tungsten equivalents.
See also
References
