Projectors are a perfect way to interact with your audience and present real time information. With outstanding images created by the latest generation projectors they also can be a superb home entertainment solution.

Choosing a projector boils down to: What you want to watch (and where), Portability (if necessary), Brightness, Contrast Ratio, Pixel Density, Color Reproduction, Inputs, Screen, and Price.

Home theater projectors are best for viewing Sports and DVD movies. If you watch mostly regular TV, an LCD/DLP projector may be an expensive option as the bulb would need to be changed after 1,000 to 2,000 hours of viewing (some projectors now have upwards of 3,000 bulb life; and this continues to improve). Also, make sure you have the proper room size for your projector.

Portability is important; not just enabling you to move or travel with your projector, but simplifies installation and setup. It also makes it easy to try different screen sizes, distances, and different rooms to see what works best. If your projector is portable you can even hang a sheet on an outside wall (or garage door)in the summertime and enjoy your own drive-in movies!

Brightness: Without sufficient brightness your image will look muddy and soft, even in a dark room. Check the ANSI Lumens rating. Relatively speaking, projectors with 1,000 ANSI Lumens or greater have sufficient brightness for home theater use. Room size and screen size/distance will affect the need for more or less lumens.

Contrast Ratio complements brightness. High contrast ratios deliver whiter whites and blacker blacks. A projector may have a great Lumens rating, but if the contrast ratio is low, you image will look washed out. Contrast ratios of at least 1,500:1 are good, but 2,000:1 or higher is considered excellent.

Pixel Density is important, especially for LCD/DLP units. As stated earlier, LCD and DLP-based video projectors have a fixed number of pixels on their display chips. If most of your viewing is HDTV, get as high a native pixel count as possible. A native pixel count of 1024x768 is sufficient for DVD. However, 720p HDTV signals require a 1280x720 pixel count to give you a one-for-one representation of a 720p signal while, as mentioned earlier, a 1080i HDTV input signal needs a native pixel count of 1920x1080 for a one-for-one representation of the 1080i signal.

If a projector's pixel count is less and it accepts HDTV input signals, the signal is scaled to fit the number of pixels on the chip. In addition, some projectors also upscale a lower resolution image to match a higher pixel count on the chip. Scaling can work both ways. Check specifications for this capability.

If the projector has a good built-in scaler, the image should look smooth, and fairly consistent, no matter what the input source is (however, other factors, such as a poor film source print, degraded VHS video, and degraded color or gray scale consistency on the source material can affect results). Scaling cannot correct for poor source material, but can make your source look as good as it can look, based on the projector's native pixel field. There are also outboard video scalers and processors than can be used, which are often preferred in high-end video projection installations, especially if the projector is being used to project a very large image.

Color Reproduction is another factor. Check for natural flesh tones and color depth. Check how colors look in the brightest and darkest areas of the image. Check the degree of color stability from input to input. Everyone has a slight difference in color perception and what looks pleasing. Look carefully.

Make sure the projector has the inputs you need, such composite and S-video for analog sources, component inputs for DVD, and DVI or HDMI inputs for HDTV. Most projectors also have VGA-type inputs for computers.

Screens come in various fabrics, sizes, and prices. You could use that old 8mm film projection screen or just put up a sheet, but to get the most out of your projector, spend money on a good screen. The type of screen that's best depends on the projector, the viewing angle, the amount of ambient light in the room, and the distance of the projector from the screen. Consult a video screen dealer.

The fastest growing type of video projector (in terms of sales) in use today is the DLP (Digital Light Processing) projector. Like LCD, the actual image is displayed on a chip, however, the chip used in a DLP projector is different. The chip in a DLP projector is referred to as a DMD (Digital Micromirror Device). In essence, every pixel on a DMD chip is a reflective mirror.

The advantages of this system make the DLP projector suitable for not only business and home theater application, but DLP technology is also in use in some movie theaters for feature film projection. Basically the films are digitally converted and stored to either to a hard drive or optical disc (similar to DVD - only in High Definition), then fed into the DLP projector and projected onto the movie screen. The high resolution DLP chips made for this application render an image that is almost as good as 35 or 70mm film, without all those film scratches!

Other advantages of the DLP projector include excellent color accuracy, no "screen door" effect(as with LCD), due to its micro-mirror construction, compactness, low power consumption, and high contrast and brightness (although typically not as bright as LCD types but much "smoother" looking).

1. Just as with LCD, each DLP chip has a finite number of pixels.
2. Although a DLP projector doesn't exhibit the "screen door" effect of many LCD units, a DLP projector can exhibit what is referred to as "the rainbow effect". Basically, the "rainbow effect" is exhibited by a brief flash of colors (like a small rainbow) when the viewer rapidly looks from side to side on the screen or looks rapidly from the screen to side of the room. Fortunately, this does not occur frequently and many people do not have sensitivity to this effect at all.
3. Just as in LCD projectors, the light source must be changed every 1,000 to 2,000 hours.

An LCD projector basically works by passing a powerful light source through a transparent LCD chip made up of individual pixels (which displays the moving video image) and projecting that image through a lens to a large screen.

What makes the LCD projector very practical is that it is compact, since the LCD chip is very small. One LCD chip is hundreds of times smaller than the three projection tubes needed in CRT projectors. Other advantages of the LCD projector is its high contrast and brightness capability, as well as lower power consumption. This combination of factors make the LCD projector very portable for multimedia use, such as business presentations (even in partially lit rooms). Also, with some modification, an LCD projector can provide an excellent option for home theater use. Probably the final "hook" is that an LCD projector is fairly inexpensive, when compared to CRT types. A basic LCD projector, suitable for portable business presentations, start at about $1,000 with units suited more for home theater starting at about $3,000, which is much less than any CRT counterpart.

1. visible on a large screen, thus giving the appearance of viewing the image through a "screen door".
2. When using a business-type LCD projector in a home theater setup, the image may appear too harsh with regards to brightness and contrast.
3. Since an LCD chip is made up of a panel of individual pixels, if one pixel burns out it displays an annoying black or white dot on the projected image. Individual pixels cannot be repaired, if one or more pixels burn out, the entire chip has to be replaced.
4. Since LCD chips have a finite number of pixels, signal inputs that have higher resolutions must be scaled to fit the pixel field count of the particular LCD chip. For example, a typical HDTV input format of 1080i needs a native display of 1920x1080 pixels for a one-to-one display of the HDTV image. However, if your LCD chip only has a pixel field of 1024x768, the original HDTV signal must be scaled to fit the 1024x768 pixel count on the LCD chip (in addition the image will also have to be letterboxed to reproduce the correct widescreen aspect ratio). This is where CRT projectors can excel over an LCD projector, since they are not limited by a fixed pixel field, they are more flexible at displaying various resolutions, due to being able to varibly scan the image onto the projection tube surface.
5. As mentioned earlier, the LCD light source (bulb)in an LCD projector must be replaced periodically, depending on the projector, about every 1,000 to 2,000 hours, at a cost of several hundred dollars. On the positive side of this, a new lamp basically gives you a new LCD projector, as your original brightness and contrast are restored, and most bulbs can be self-installed by the consumer.

Other variants of LCD video projection technology in use are: LCOS (Liquid Crystal on Silicon), D-ILA (Digital Imaging Light Amplification - developed and used by JVC), and SXRD (Silicon Crystal Reflective Display - developed and used by Sony).