Plasma was the first flat-TV technology that could reproduce good quality images at home theater-sized screens of 42" and up (LCD took several years to catch up). It has been on the market since the late 1990s and has undergone many improvements along the way, not to mention major price reductions. The first plasma TVs for the home didn't have enough pixels reproduce HD signals and cost over $10,000. Today, you can get a full HD (1080p) plasma set for a tiny fraction of that price.
In terms of pure picture quality, many experts feel that plasma is the reigning champion of TV technologies. It offers deep, dark blacks, and these are the vital cornerstones of picture detail. Because of the way plasma TVs produce images, they're capable of smoother motion on fast-moving images than competing LCD and many LED TVs. If you watch a lot of sports and action movies this is a real advantage. Plasma TVs also have a wider "stable" viewing angle (no change in image) than other technologies, so if you, your family or your friends will typically sit "off-axis" (at an angle) to the TV, plasma is a good choice.
Because plasma TVs are less economical to manufacture, most manufacturers have moved to other technologies, mostly LCD. Consequently, you won't find as many brand choices with plasma. Plasma TVs also have a technological drawback; if you leave a stationary image (like a TV station ID or a video game score) on-screen for too long a time, there's a tendency for temporary "burn-in" – you can see an after-image even after it's no longer part of the programming. To be sure, this is no longer the problem that it was in plasma's early days, but if you routinely watch hours of continuous programming with static logos or scores or stock reports running at the bottom of the screen, take this into consideration when you buy. Also know that plasma is not manufactured in small screen sizes – you won't see any sets under 42 inches.
Though it took a while for LCD to catch up to plasma in terms of market acceptance and pricing, this is now the most common TV technology and available in a mind-boggling range of brands, sizes and model choices. Because of this broad range, picture quality can vary greatly, sometimes even between different models from the same brand.
In general, LCD TVs live better in brightly lit rooms than non LCD technologies. Because of the way they produce light and pictures, LCD TVs are designed to block outside light, meaning that their screens are often non-reflective and light output from the screen is often perceptibly higher than with other technologies. LCD TVs also produce less heat than plasma TVs and typically consume less electricity. Except in extreme cases, LCD TVs are not affected by possible screen "burn-in" and are a good choice when stationary images are a big part of your viewing needs. Finally, LCD will give you the biggest selection of prices and screen sizes.
More than other TV technologies, LCD TVs vary greatly in picture quality. This is a natural effect of the huge number of models available, but also because LCD is economical to manufacture and many makers strive to hit lowest possible price points, particularly on entry-level models. LCD's main technological challenge is fast-moving images; on some sets you can see a trail of pixels or a "blocky" look on fast motion. Manufacturers try to remedy this with various "motion" enhancements, sometimes successfully, sometimes less so. Conventional LCD TVs also don't reproduce the color black as well as other technologies, which results in less detail and contrast than you can get elsewhere. Finally, the picture on many LCD TVs is visibly different when you watch from too far of an angle.
A recent newcomer to the TV landscape, LED TVs are actually LCD TVs with a different light-producing method. Every LCD-based display needs to have its pixels "lit up" in order to produce images. On conventional LCD sets, a fluorescent lamp at the rear of the set is used, but on LED sets, smaller and more efficient LED lights replace this. There are two kinds of LED TVs. One of them is called LED "edge lighting" – instead of a big lamp behind the pixels, smaller LED lamps around the edge of the screen are used. This is the less expensive LED method. In the more elaborate (and expensive) "local dimming" LED method, several rows of LED lamps are placed at the rear of the screen and allow nearby "local" pixels to be fully on or off, depending on the momentary needs of the program you're watching. This results in better contrast.
Because LED lighting is brighter and more efficient than fluorescent lighting, the picture on an LED TV "pops" more than on a conventional LCD set, with better contrast and detail, often approaching the picture quality of better plasma sets. This is especially true of local dimming LED sets, which are also called "full LED" models. LED sets that use the less costly "edge" lighting technology can be made tremendously thin – often less than an inch thick. While nice on a cosmetic level, this achievement has no effect on picture quality. Both LED TV types are more energy efficient than either plasma or conventional LCD TV, which means lower electricity bills and a greener household.
Because it is a new technology, LED TVs are more costly than LCD TVs, though this will certainly change very quickly due to price pressures and lots of new models from the major manufacturers. Also as a result of its newness to the market, there are fewer choices in LED TV; you won't find as many brands or screen sizes to choose from. Also, since LED is essentially an LCD technology, viewing angle is an issue; picture quality can vary if you sit at too much of an angle to the TV.
While most of the market has shifted to flat-screen TVs, one manufacturer, Mitsubishi, continues to offer large "rear-screen projection" TVs based on the Digital Light Processing (DLP) engine developed by Texas Instruments in the early 1990s. This is the same technology used for digital projection in movie theaters, and employs a chip with millions of tiny mirrors that reflect light (and pictures) to the screen based on the real-time needs of the program material. While these TVs are not flat, they are not as deep as old-school analog TVs, and come in an impressive range of big-screen sizes.
DLP is a mature technology that is capable of outstanding picture quality. It performs well in bright or dark rooms and has good off-angle viewing characteristics. In addition to picture quality, DLP's big advantage is bang for the buck – you can get a large size DLP screen for less money than a flat screen model of comparable size, and in the case of the largest screens (60 inches and over), for a lot less money. DLP TVs are also available in 3D models.
There are two primary drawbacks to DLP. The main one is that only one manufacturer still offers this technology – Mitsubishi. If the lack of brand choices doesn't bother you (Mitsubishi is a well-established manufacturer) this obviously isn't an issue. The second drawback is size; DLP TVs are not flat. You'll need a lot more shelf space (or floor space) for a DLP TV, but if you've got the room for it and don't mind that your TV isn't flat, this isn't a problem. There are no small DLP TVs; they are only offered in large screen sizes of 65 inches and up. # # #