Almost all business and home theater projectors rely on lamps that use mercury. We’ll call them UHP lamps, but they are mercury vapor lamps. They are basically a cousin of the mercury vapor lamps used in street lights. When you read about the lamps in projectors, though, you’ll see them called UHP (ultra high pressure), or any of a half dozen plus acronyms. Trying to tell them apart by the different names, is mostly a waste of time. UHP, UHM, NSH, UHE, etc, are the same thing, in almost all cases. Shown to the right – a Sanyo projector lamp, in its custom holder.
There is a second type of lamp in use, on very high end, and extremely bright projectors, and these work differently. They are xenon lamps. Overall, they have a better color range than the UHP type lamps, and use xenon, not mercury.
These xenon lamps tend to be significantly more expensive, and have a shorter life than most UHP lamps. They tend to start at over $1000, and typically have a lamp life of 500 to 1500 hours compared to UHP lamps good for 1500 to 5000 hours.