In 1996, the Federal Communications Commission (FCC) enacted legislation convincing the nation's 1600+ television stations to change the way they broadcast their programming and to start transmitting it digitally. Digital Television (DTV) began rising in America ever since then. For now, the FCC allows the media to offer digital broadcasts in parallel with their existing analog ones, giving consumers the opportunity to watch regular TV while they make the switch to DTV.

Once the transition to digital TV is complete it is estimated that by the year 2006 85% of US households will get digital feeds, meaning that DTV will be the new standard in broadcasting replacing analog broadcasting. Sure, you'll still be able to watch your favorite shows in analog like always, but you'll need to "update" your existing TV with a device that converts digital signals into analog ones. All of which begs the question: Why not just go with the digital flow?

Projection Lenses - A key element in rear-projection television, are the type of lenses used to magnify the projected image. There are usually several lenses used. It is usual for a rear-projection television to use four or five lenses while some sets use more. The reason for this is that several successive lenses are needed to maintain the shape and brightness integrity of the image. It is very easy for a single lens to make things look good in the center of the image, but as the light and image content is spread across the screen, additional lenses are needed to maintain the overall image shape so that objects in the image look the same on the sides and corners as they do in the center of the screen.

In terms of the physical construction of the lenses themselves, all-glass lenses are the best, especially in terms of withstanding high temperatures from both internal and external factors. However, many manufacturers use a combination of glass and acrylic-based lens construction. This may not be bad, but there may be noticeable differences not only in the final image, but the overall image performance in the long term.

Mirrors - A necessary element in the design of a rear-projection television is the mirror. Since the projected image has to project on to a large surface within a relatively small space a mirror is placed in the path of the projection element, magnifying lenses, and the screen. This allows the projection elements and magnifying lenses to be placed at the bottom of the projection television cabinet. This gives the projected image a longer path to the screen itself so that a larger image can be presented as well as redirecting the path of the projected image so that it will be facing the viewer correctly.

The Screen - An important element of a rear-projection television is the actual screen upon which the image is seen by viewer. The type of screen used in projection televisions is much different than those used for front video projection or film. A rear-projection television screen is made up of two primary elements. First, there is the inner Fresnel surface, which magnifies and disperses the brightness of the image across the screen. Second, there is an outer Lenticular surface, which helps in the final shape integrity of the image, as well as contributing to contrast and the wideness of the televisions viewing angle. If you were to touch a rear-projection television screen (which you should never do under normal circumstances) you would notice that its surface is not smooth, as is a standard film or video projection screen. This is because you are actually touching the Lenticular surface etched into the screen itself.

The Box - The last key element of the rear-projection television itself is the box in which all the elements are sealed in. The size of the box is directly related to the size of the screen surface itself. Rear projection televisions can be any size, but, practically speaking, they come in sizes housing 41-inch to 76-inch screens. The size of the box that is right for you is determined by your room size and/or you actual viewing distance from the television screen.

LCD VS Plasma - At first if you were dreaming of a super size flat screen for your home entertainment center Plasma Televisions were your only option. But recently large-format LCD TVs have been competing with plasma displays in prices and sizes.

Right now, Plasma Televisions have an advantage and that’s partly because, at the moment, large LCD Televisions simply can't compete on price. It's also because plasma screens have a greater response time than most LCD TVs which makes LCD Televisions less than optimal for moving images such as video or games. The drawbacks that Plasma TV screens had in the past such as stationary images burning in and producing permanent ghosting has diminished greatly in newer products. For example, some new companies have developed technology to deal with the problem by moving stationary pixels just enough to prevent such burn-in.

But LCD Televisions do have some advantages over plasma. If you're contemplating a home entertainment setup involving a PC or other activities involving text as well as graphics, you'll get a crisper, brighter image from an LCD. LCD modules are in use for all types of products, from handhelds to monitors to TVs. As time passes larger LCD TVs will be available at lower prices, because they offer better screen quality, higher reliability (LCD TVs have none of the burn-in issues associated with plasma), and longer product life. LCD Televisions last for about 50,000 hours versus 30,000 hours for today's plasma screens. LCD TVs weigh 10 to 15 percent less than plasmas of comparable size. They often look better in daylight than plasmas, though plasmas have a brightness advantage at night.

LCD VS DLP - DLP technology is superior to LCD projection in numerous ways. Digital Light Processing technology ensures that every pixel on your projected image gets exactly the same amount of light, there is no fading around the edges of the screen, and colors look sharp. Also, DLP consists of one single chip, instead of three bulky LCD panels, resulting in smaller lighter projectors without any loss of image quality. Reduced pixilation is another benefit of DLP. LCD Televisions were always known for their visible pixel structure, often referred to as the screendoor effect because it appears as though the picture is being viewed through a screendoor. DLP will always give you the better visual image and it can produce higher contrast video with deeper black levels than you normally get on an LCD projector. DLP Televisions have Higher Contrast. The simple optical system reduces the unwanted effect of "stray" light, allowing for better contrast ratios, which means sharper, more detailed images.

There is one single issue that people point to as a weakness in DLP, it is that the use of a spinning color wheel to modulate the image has the potential to produce a unique visible artifact on the screen that folks refer to as the "rainbow effect," which is simply colors separating out in distinct red, green, and blue. Basically, at any given instant in time, the image on the screen is either red, or green, or blue, and the technology relies upon your eyes not being able to detect the rapid changes from one to the other. Unfortunately some people can.

LCD VS CRT Monitors - Free from the bulky shape and size of the CRT screen an LCD Screen is light and slim in size, compare a 15-inch deep, 30-pound CRT against a panel that's less than 7 inches deep (including the base) and weighs 12 or 13 pounds. It's easy to see the advantages of LCD monitors, they don't have CRT's focus problems, and their clarity makes it easier to view higher resolutions at smaller screen sizes. The latest LCD monitors are all digital, unlike CRTs this means that graphics cards with digital outputs don't have to convert the graphics information into analog form as they would with a typical CRT monitor. With LCD TVs you will get a high quality image with very little eyestrain due to the flat screen and the screens do not flicker unlike in the CRTs.

Brightness - Without sufficient brightness your image will look muddy and soft, even in a dark room. Check the ANSI Lumens rating. Relatively speaking, projection assemblies producing 1,000 ANSI Lumens is plenty for a rear-projection television. However, since the light is reflected onto a screen, the light intensity coming from the screen, into the viewing room itself, is more important.

Contrast Ratio - complements brightness. High contrast ratios deliver whiter whites and blacker blacks. A rear-projection television may have a great Lumens rating, but if the contrast ratio is low, your image will look washed out. A Contrast ratio of at least 1,000:1 or higher is considered excellent.

Pixel Density - is important, with regard for LCD/DLP units. 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. If a projection set's pixel count is less and it accepts HDTV input signals, the signal is scaled to fit the number of pixels on the chip which will reduce the quality of the picture that the LCD rear-projector can produce.

Color Reproduction - 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.

Viewing Angle - All projection televisions have a problem with side viewing. Although viewing angles for rear projection televisions have improved greatly in recent years, with some offering 130 degrees or more, optimum viewing is still best from the center of the screen out to a 45 degree angle, with acceptable viewing possibly out to 90 degrees. In other words, all the viewers sitting on a large couch shouldn't have a problem, but someone sitting in a chair off to the side will not get an optimum view of the screen.

Inputs - 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. Some rear-projection televisions now have VGA or similar inputs that enable it to be used with a computer for video presentations or game play.