Brightness is measured in lumens. The lumens can range anywhere from 300 lumens to 3300 lumens, with 3300 being the brightest. Lumen Range Comments 300 - 500 lumens These will usually be the least expensive projectors. Also, the low light output may require your presentations to be made in a dark or dimly lit room. 500 - 1000 lumens Projectors in this range are geared toward normal business conference room and classroom use. You may have to reduce lighting a little, but a totally dark or dimly lit room is not necessary. 1000 - 1500 lumens Aimed at large conference rooms and classrooms, these machines project a bright image even with lights on. 1500 - lumens and up These projectors are used for nightclubs, concert halls, auditoriums, churches and other large venues. With this information in mind, there are some things to consider when choosing your brightness. the Light in the Room No matter the brightness of your projector is, a dark room will always provide the best image. However, many situations require some light for note taking and communication. If a room''s lighting cannot be controlled, a bright projector will be needed.

Picking the right resolution Here are some basic guidelines for choosing the right resolution: Pick a resolution that is adequate for your presentation. If you use mostly type presentations, you can save money by going with a lower (SVGA) resolution. If you are, however, presenting information with a lot of numeric data, you may want an XGA resolution. And for highly detailed and technical presentations, such as engineering drawings, you may need the higher resolution SXGA projector. Get a projector that matches the native resolution of your computer. If you have a computer with SVGA resolution, then an SVGA projector will give the sharpest and cleanest image. Most of the projectors today can project input signals other than their native resolution, however, there may be a loss of sharpness and detail in the process. If you have a high resolution computer and a matching resolution projector is out of your price range, choose a projector that is one step down in resolution. Projectors convert a different input format to its native output format through a process called "scaling". Some projector are very good at scaling, thus making the fuzziness in the image very minor. The quality of scaling varies among different projectors.

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!

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