Saturday, October 2, 2010

Plasma vs. LCD vs. Plasma vs. LCD vs. LED

The biggest television technology revolution since color, flat-panel TVs are replacing tubes as the direct-view televisions of choice. You can hang flat sets on the wall, on the ceiling or above the mantle in place of a trophy buck. The three major players in the flat screen game are plasma, LCD and LED, so we'll go over each type separately.

1. Plasma
LG PQ60-series plasma TV
With promotional prices starting at S$899, a coveted plasma TV is within reach of most shoppers. But now that you can get a 42-inch LCD for just S$200 more, plasmas have to depend on factors other than price to remain competitive against their LCD nemeses.

Picture quality varies greatly between different brands, so be sure to read reviews before you plonk down your cash. Most plasmas can produce near CRT-quality blacks, with excellent color and viewing angles. That said, some similarly sized LCDs and LEDs also have higher resolutions, delivering more details and smooth game graphics.

Burn-in: This occurs when an image--such as a network logo or letterbox bars--gets etched permanently onto the screen because it sits in one place too long. In our experience, this issue has been greatly exaggerated. The burn-in risk is greatest during the first 100 or so hours of use, during which time you should keep contrast low (less than 50 percent) and avoid showing static images for hours at a time. Many plasmas also have burn-in-reduction features such as screensavers and pixel orbiting, or functions to treat burn-in once it occurs, such as causing the screen to go all white.

Plasma lifespan: Most plasma makers today rate their latest models as having a lifespan of up to 100,000 hours before the display fades to half brightness. On average, that works out to more than 17 years before the set reaches half-brightness.

Best black levels; very good home theater image quality in best examples; wide viewing angle.
Slight potential for burn-in; reflective screen; lower native resolution than similarly sized LCDs and LEDs for entry-level models.
More 50-inch and larger full-HD models to come, cementing plasma's place as a favorite among videopiles and enthusiasts.

2. LCD
LG LH50-series LCD TV
Flat LCDs are extremely popular in screen sizes below 47 inches, thanks to their widespread availability and vast selection. Larger LCDs--as big as 70 inches--remain more expensive than plasma, but in the critical 40- to 42-inch size range, LCD prices have dropped precipitously to as low as S$1,099 during sales.

The LCD picture quality has historically suffered from poor black levels, but the latest versions are much improved. That's because LCDs cannot achieve true black since there's always some light leaking through the pixels. In this respect, color saturation is also affected as well.

Viewing angle: This is another LCD weakness compared to plasma. Some brightness and color shift can be visible when we watch from an angle that's far from the sweet spot right in front of the TV (to either side, above and below). Higher-end models based on In-Plane Switching (IPS) technology and derivatives such as Super-IPS and Alpha-IPS are known to perform dramatically better in this department.

Motion reproduction: LCD spec sheets often talk about response time, but in our experience, almost all newer LCDs have adequate response time to deal with fast motion. To further boost image fluidity, many vendors have also introduced 100Hz and 200Hz engines. Some of them are implemented using frame interpolation and/or backlight-scanning processing.

Higher resolution than comparable-sized plasmas; no danger of burn-in; available in a wide range of sizes.
Relatively expensive for 60-inch and larger panels; black level quality generally not as good as plasma due to backlighting; relatively narrower viewing angle.
Flat-panel LCD will continue to be the most popular HDTV technology, thanks to falling prices and strong manufacturer support.

3. LED
LG SL90-series LED TV
LED TVs are a subset of LCD panels. Rather than use conventional cold cathode florescent lamps (CCFL) to illuminate the LCD pixels, they employ tiny light-emitting diodes. There're two predominant types used by the vendors based on conventional rear (back) and the latest edge lighting with street prices starting at S$2,199.

Backlit LED TVs also support the local dimming function which independently illuminates different clusters of pixels. This produces plasma-like blacks in scenes with concurrent dark and bright details as opposed to global dimming used in edgelit models. That said, the latter employs fewer diodes, which allow for slimmer TVs and higher power savings.

Energy efficiency: An LED TV consumes the least power among all HDTVs with a substantial energy savings of up to 40 percent compared with a conventional lamp-based LCD model. The other major benefits of using light-emitting diodes include an extended panel lifespan, low heat emission and better eco-friendliness. The latter is due to the mercury-free design of these energy-efficient bulbs.

Ultraslim design: Another advantage of edge lighting is that it frees up space behind the screen, which significally reduces bezel depth, giving rise to a family of ultraslim panels measuring as thin as 29.1mm in width. Putting aside the "wow" factor, these lightweight displays are much easier to install. Some can even be suspended on a special steel wire wall-mounting kit, just like a photo frame.

Plasma-like blacks on top of most of LCD's advantages; high energy efficiency; ultraslim design.
The priciest among all HDTVs; limited screen sizes from 40-inch and above; relatively narrower viewing angle.
LED TVs will gradually replace their LCD counterparts, though the former is probably going to cost a premium in the following years.

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