Among flat-panel displays, consumers have three primary options in plasma, LCD and LED-based LCDs. Although the three sets might have superficial similarities, there are core differences in how the image is illuminated, energy efficiency, black levels, color rendition and how the set handles on-screen motion. Understanding these differences before you hit the showroom floor helps you wade through the sea of seemingly identical TV choices.
1Plasma: Plasma televisions traditionally offer measurably deeper blacks and more accurate color than their LCD cousins. This is achieved through use of phosphor, the element used for decades in tube televisions. Even light output is achieved through illumination of the phosphor directly from electric current, as opposed to some form of backlighting as in LCD technology. Viewers sitting off center find uniform black levels and color, making any seat an acceptable one. Plasma televisions routinely offer refresh rates in the 600 Hertz range, making motion smooth and judder-free. Although plasma sets are not quite as energy efficient as LCDs, that parameter has improved from the technology's inception late in the last century. Despite all of these positives, plasma remains price competitive, often coming in lower than comparable LCD technologies.
2Traditional LCD: Cold cathode florescent, or CCFL, technology comprises the majority of lower-end and smaller LCD televisions. A proven technology, CCFL LCDs offer bright, crisp images. Upper-end CCFL LCDs offer high refresh rates up to 480 Hertz, removing stuttering on credits and streaks on fast-moving objects. However, screen uniformity varies significantly, with users reporting "clouds" or splotchy portions of the screen where the light leaks through. Although all LCDs potentially suffer from this to one degree or another, CCFL models are particularly egregious, with two examples of the same model exhibiting different levels of uniformity. Despite these issues, CCFL LCD sets are long-lasting, cost-effective and energy efficient, spanning nearly all screen sizes to fit any scenario.
3LED LCD: The winner in energy efficiency, LED-based sets use light emitting diodes for illumination rather than florescent lamps. Deployed across the entire surface of the screen on high-end models, these LEDs offer significantly deeper blacks than CCFL versions. This is accomplished by turning off select LEDs to remove light, thus generating black. Many LED televisions, however, place the LED light sources around the perimeter of the screen, known as edge-lighting. Light is then dispersed across the screen via light guides. The advantage to the latter version over CCFL is mainly energy efficiency and thinner chassis measuring 1 inch or less. Among all flat panels, LED LCDs are positioned at the high end among LCD displays and are therefore normally the priciest. For critical viewers, LED sets can offer performance competing with better plasmas.
4Room Considerations: The best television technologies are for naught if they're placed in the wrong environments. Key to this decision are relative brightness and screen reflectivity. Although there are exceptions, plasma televisions normally have glossier screens and lower light output. As a result, it's generally recommended to avoid use of these sets in rooms with large amounts of natural or artificial light. LCD televisions of both types usually employ a matte-finish screen, although there are some exceptions among higher-end sets. In these cases, the screen -- as with plasma -- uses a glare coating to diffuse light across the surface, rather than directly back at the viewer. LCDs and especially LED variants offer much higher light output as well, making them ideal in nearly any environment, since you can always decrease light output.