Plasma vs LCD Technology
16 January 2009
This is a much debated topic (and a fun one). When choosing between Plasma and LCD TVs, you're actually selecting between two competing technologies, both of which achieve similar features (i.e. Bright crystal-clear images, super colour-filled pictures) and come in similar packages (i.e. 3.5 inch depth flat screen casing). To complicate the decision-making process further, price and size are two previous considerations that are rapidly becoming non-issues as LCD TVs are now being made in larger sizes and at competing prices with Plasma.
Despite their similarities, the two technologies are very different in the way they deliver the image to the viewer.
Plasma technology consists of hundreds of thousands of individual pixel cells, which allow electric pulses (stemming from electrodes) to excite rare natural gases (usually xenon and neon) causing them to glow and produce light. This light illuminates the proper balance of red, green, or blue phosphors contained in each cell to display the proper colour sequence from the light. Each pixel cell is essentially an individual microscopic fluorescent light bulb, receiving instruction from software contained on the rear electrostatic silicon board. Look very closely at a Plasma TV and you can actually see the individual pixel cell coloration of red, green, and blue bars. You can also see the black ribs which separate each.
Whether spread across a flat-panel screen or placed in the heart of a projector, all LCD displays come from the same technological background. A matrix of thin-film transistors (TFTs) supplies voltage to liquid-crystal-filled cells sandwiched between two sheets of glass. When hit with an electrical charge, the crystals untwist to an exact degree to filter white light generated by a lamp behind the screen (for flat-panel TVs) or one projecting through a small LCD chip (for projection TVs). LCD TVs reproduce colours through a process of subtraction: They block out particular colour wavelengths from the spectrum of white light until they're left with just the right color. And, it's the intensity of light permitted to pass through this liquid-crystal matrix that enables LCD televisions to display images chock-full of colours, or gradations of them.
The great marketing machines of Philips, Sony, Samsung and Panasonic have combined with major electronics retailers to work everybody into a flat-panel frenzy (even people who say they don't watch TV!). The only problem, of course, is that there happen to be two kinds of flat panels, and both have their pluses and minuses. With that in mind, I've put together a quick rundown of what you should know before going the Plasma or LCD route, along with a few pointers.
1. Price-to-size ratio
While neither LCD nor Plasma TVs are a budget bargain, on a price-per-square-inch basis, Plasmas currently have a slight edge. Look at it this way: Technically, a 42-inch Plasma gives you approximately 30 percent extra screen real estate as a 37-inch LCD panel, but they both go for about R 12.000. Prices have almost halved in the last twelve months, but larger versions (50 inches or more) won't cost the same as their Plasma equivalents for quite a while.
Today, 26 inches are about the smallest the mainstream manufacturers sell. Plasmas aren't available in that size; 32 inches is their lower limit, but they really start at 42-inch. Just remember that a 20-inch screen is pretty small, and you'll have to sit rather close to it. It may be fine for viewing the news and sitcoms in bed, but it's obviously less than ideal for enjoying movies. And a 17-inch model should be reserved for use as a kitchen television or a computer monitor in a home office; while you work, you can watch TV in a little picture-in-picture box in a corner of the display.
Bottom line: 32-inch LCD’s offer the greatest value among bedroom sets, and your best bet for the living room is a 40-inch or larger LCD or Plasma.
2. Performance
A general rule of thumb is that plasmas deliver better home theatre performance than LCDs. The difference is due mostly to the fact that backlighting-based LCD TVs typically can't display black as well as Plasmas; it ends up closer to dark grey. That shortcoming decreases the amount of detail you can see in the shadows and ultimately leaves the picture looking (as videophiles would say) less three-dimensional.
The picture quality of both LCD and Plasma panels is improving each year, but it can vary significantly from manufacturer to manufacturer, so check our lists of top products. We're nitpicky about performance in our reviews (it's our job) and you should seriously consider our evaluations, if you plan on using your set for home theatre viewing. But if you're buying a smaller LCD (26 inches or less) for the kitchen or the bedroom, don't agonise too much over performance.
3. Lifespan
The number of viewing hours a television provides before dimming to half brightness, used to be one of the biggest advantages LCD had over Plasma. Though the numbers vary among the different brands, they now generally last up to around 60,000 hours regardless of the technology.
4. Burning issues
One of Plasma’s technology known issues is something called burn-in. It happens when your television shows a still image or an icon for so long that its "ghost" remains on the screen. For example, if a stock ticker or a news crawl continuously runs along the bottom of your display, that strip may be burned into your set. The same applies to watching an excessive amount of standard TV (4:3) on a widescreen (16:9) model; the vertical bars to either side of the picture could become permanent. Manufacturers have taken steps to prevent burn-in, building in screensavers and other technologies. And you can virtually eliminate the danger by not leaving still images on the screen and reducing your contrast setting below 50 percent for the first 100 hours of usage.
To their credit, LCDs don't suffer from burn-in, nor do they have troubles at high altitudes where the air pressure differential causes plasmas to emit an irritating buzzing sound. So, if you live in mountainous regions, we don't recommend that you get a Plasma, though some manufacturers are selling special sets they claim are immune to the problem.
5. Viewing HDTV
Most Plasmas and LCDs can display a high-def signal. However, you'll need a model with a resolution of at least 1,280 x 720-pixel to enjoy the full effects of HD. Most 50-inch plasmas and nearly all 32-inch and larger LCDs offer this resolution. Several new 42-inch Plasmas now do, but when you're watching HD feeds on a lower-resolution television of that size or smaller, you'll have to sit much closer to notice much of a difference between HD and what you're seeing. Take Pioneer's PDP-427XG, even though the set provides a XGA resolution (1,024 x 768), HDTV looks really good on it.
6. Computers and video games
Most Plasma and LCD TVs can double as computer monitors; some even offer a DVI or D-Sub port for optimal video quality. They'll also hook up to a game console without any problems. So which technology is better for these purposes? From a performance standpoint, it's hard to pick a winner, but because of plasma's burn-in risk, LCD is the safer choice for computer work and gaming.
Conclusion:
The best way to decide on which is better, is to view Plasma and LCD panels next to each other playing the same source (and we have noticed that in terms of things that would irritate us the LCD has terrible viewing angles) colours start to look washed out if you are not 100% head on to the screen which makes LCD into a 1 person screen - whilst Plasma, even if it has an anti-glare screen will still show reflections especially in bright light (so the glass panels of Plasma need to be in darkness ,sun blocked room, to operate) hence with LCDs problem there is no way to sort it out (whereas with Plasmas’ shortcomings, you can just add a curtain to your windows) and then there is the price (on the average a 47" 1366x 768 LCD would be around R25k whilst a 50" Plasma which is marginally larger at the same resolution is around R17k) so Plasma is around an average of 25% cheaper and this is exponential the bigger the size gets.
Stefan Mayer
Operations Manager
Teljoy Audio Visual