Lamp life is commonly discussed in terms of " Half Life". This simply means the manufacture has set a limit on what they feel is the quality life of the lamp. If the lamp half life is 2000 hours, the lamp will generally last much longer although the brightness of the image may deteriorate. For example, on an LCD projector, the lamp half life is generally 2000 hours. The image brightness is normally above 85% of the original brightness up to 2000 hours. After 2000 hours you may see a drastic reduction in brightness. DLP projectors normally have less of a life and the brightness generally starts deteriorating before the half life. DLP & LCD Digital Light Processing (DLP): The commercial name for this technology from Texas Instruments (TI): The technology inside is often referred to as either "micro-mirrors", or DMD: It works this way: build a few hundred thousand tiny mirrors, and line them up in 800 rows of 600 mirrors each. Now attach a hinge to each of those 480,000 mirrors. Attach each of those 480,000 hinges to its own very tiny motor! Power each motor with electrostatic energy!

Your Application If you are giving a training presentation, you will probably need a brighter projector so the participants can read detail and take notes. A presentation using graphics and/or video will be visually less demanding and can be viewed in a darkened room. Your Screen Sufficient light reflection is provided in most screens on the market, thus making a low brightness projector look good in the right setting. The Number of People The image size increases as the number of people in the room increases. This reduces the brightness of the projector since the light is spread over a larger area. Another important thing to think about when buying a projector is the weight of the unit. If you travel quite a bit, you may want a very light weight unit. If you do not travel and want more features on the projector, you may opt for a heavier model. The Four weight classes of projector are as follows: Ultra-Mobile Ideal for the Traveling presenter. Typically weighing under 8 lbs, these machines provide a great low-weight-to-brightness ratio while maintaining the desired data resolution and video output. On the down side, some of the lightweight projectors sacrifice features such as power zoom, power focus, and remote control capabilities which can weigh the projector down.

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