It is not a simple choice when you look at the advantages and disadvantages of the two competing technologies. Not only do plasma and LCD television sets come in similar slim-line designs, both are also capable of high quality picture performance - rendering true-to-life crystal-clear images. Digital LCD screens first became popular several years ago when they were introduced as lighter, slimmer alternatives to CRT computer monitors. The differences were dramatic. When used to form a HDTV they're even more so.

LCDs produce an image by projecting a light onto a series of 'liquid' crystals sandwiched between glass rectangles. Those crystals can pass or block light as they twist internally. Not really a fluid, the term comes from the fact that the crystals can twist easily when subjected to an electrical current. Varying the voltage changes the amount of twist, which results in more or less of the rear-projected light being blocked.

That curious bit of physics gives LCDs their great advantages and introduces some hurdles for manufactures trying to produce great pictures at affordable prices.

The rectangles making up the screen are arranged in rows of pixels ('picture elements') and are actually composed of three, colored sub-pixels set side-by-side. That close spacing and the precise control of twist allows designers to produce an image with great resolution, accurate color reproduction and astounding clarity.

Since every pixel contains the three colors needed - red, green and blue - to form any perceivable color, LCD sets can produce a very realistic color image. But doing so requires that 'behind-the-scenes' the pixels filter the white fluorescent backlight projected onto them.

That arrangement leads inherently to attractive, bright images that plasma type sets can't quite match. However, as sets age, that backlight can dim or change color, reducing their advantage.

Some sets offer the option of replacing the backlight, but that can be expensive. Current models have good lifetimes, though, and by the time it becomes a problem many will be looking to replace the set with the latest technology.

LCDs retain that bright, clear image better than most plasmas even under varying light conditions. Both types perform well in darkened rooms, but LCDs have a slight advantage under brighter conditions and more room arrangements. Inherently anti-glare, these sets look great in almost anyone's setup.

Screen Size
For several years, plasma dominated the upper reaches of size, while LCD often outperformed in the smaller (13" to 37") range. With improved technology, both types do well, with LCDs now available as large as 65". Though, of course, you pay a premium for the larger size.

Viewing Angle
During those same years, plasmas held the advantage in viewing angle. The nature of LCD panels makes them lose some contrast and the ability to project deep blacks as the viewer moves to the side. Images can look gray and 'washed-out'. Even colors can shift subtly.

Current sets have reduced that problem to a minimum so that under most viewing conditions it will be unnoticeable. For several years 130 degrees was about the best one could hope for, but 160 degrees or more is common today. That covers a field that would satisfy just about any normal setup.

Product Life
Both plasma and LCD TVs have a half-life of 30,000-60,000 hours. Half life is the time it takes the lamp/backlight intensity to fade to half its original brightness. Given that the average household watches TV for about 5 hours per day, a set would last 16 years before reaching its half life. Both plasma and LCD will be obsolete by then.

LCDs offer a wide range of uses. In the morning they may serve as a great looking computer monitor, in the afternoon as a game console and in the evening make a first-rate HDTV set. Older models struggled with motion blur (games and some films or shows require 12-15ms response times to avoid streaking), but current offerings have largely overcome that limitation.

The playing field for LCD and plasma has leveled to a significant extent the last few years. Today, except for the extreme sizes, the choice comes down primarily to price, reliability and that ever elusive 'best picture' quality. Be sure to 'test drive' any set you consider under good lighting conditions with a quality source.