Plasma TV vs. LCD

Reviewer: Phil Connor
 

Copyright © 2007 PlasmaTVBuyingGuide.com. All Rights Reserved.

This is a complicated topic: when choosing between LCD and plasma TVs, you're actually selecting between two competing technologies, both of which achieve similar features (i.e., bright, crystal-clear images, super color saturated pictures) and come in similar packages (i.e., 3.5 to 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 LCDs are now being made in larger sizes and at competing prices with plasma TVs.

Despite all these similarities, these technologies differ in how they process and display incoming video/computer signals.

Plasma flat screen 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 color sequence from the light. Each pixel cell is essentially an individual microscopic florescent 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 monitors reproduce colors through a process of subtraction: They block out particular color 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 colors-or gradations of them.

 

PICTURE QUALITY

As the above advantages show, plasma technology has the better picture quality in normal to low room lighting conditions and are better in 4 out of 5 picture quality categories. Plasma technology will almost without exception triumph during night time viewing. LCD televisions are great for sunroom/breakfast room type environments. Also, LCD monitors are generally better for public display such as airport signage and retail store signage due to the bright room light environment. See full article on plasma vs. LCD picture quality.

ADVANTAGE: Plasma

 

FUNCTIONAL CONSIDERATIONS

COMPUTER USE

LCD monitors display static images from computer or VGA sources extremely well, with full color detail, no flicker, and no screen burn-in. Moreover, the number of pixels per square inch on an LCD display is typically higher than other display technologies, so LCD monitors are especially good at displaying large amounts of data - like you would find on an Excel spreadsheet for example - with exceptional clarity and precision. For the same reasons, LCDs will also be a slightly better template for video gaming.

Plasma technology has increased anti burn in tactics as well as computer and static signal handling. There are still issues with each depending very much on the model and manufacturer. For example, most EDTV plasma televisions do not handle a computer input well and product a very jaggy image when viewing static images from same. Users may want to consider an commercial version plasma display if their application calls for a lot of computer use.

ADVANTAGE: LCD

Pats Opinion: I have had no issue with pc on my Plasma. Wow runs fine.

 

FAST-MOVING VIDEO PLAYBACK

Plasma displays get the nod here because of their excellent performance with fast-moving images and high contrast levels. There are still some 2^nd tier manufacturers whose plasma product displays some phosphor lag, a dragging from brights to darks.

While the "response time" of LCD TVs has markedly improved in the last couple of years, they still suffer from a slight "trailer" effect, where the individual pixels are just slightly out of step with the image on the screen. During fast moving sports scenes, the most discerning eyes can detect this slight motion response lag.

ADVANTAGE: Plasma

 

VIEWING ANGLES

Plasma manufacturers have made much of their 160° viewing angles, which is about as good as horizontal and vertical viewing angles get. This owes to the fact that each pixel produces its own light, rather than light being spread across the screen from one central source. Hence, each pixel is more readily visible because its brightness is consistent with every other pixel on the screen. One consistent area of superiority of plasma viewing angles is demonstrated when viewing dark material content, especially DVDs. A Plasma display holds the black levels from off axis, while LCD TVs lose black level intensity more as the angle off axis increases. This usually occurs after around 90 degrees.

LCD TV manufacturers have done much to improve their displays' viewing angles. The substrate material on newer-generation LCD models by Sharp and Sony has helped to expand those units' viewing angles, though they still have some ground to cover before catching plasma. Expect the best LCD HDTVs to have between 120 and 130 degree viewing angles.

ADVANTAGE: Plasma

 

 

ALTITUDE USAGE

There is a reason LCD panels are the preferred visual display units for use on airplanes: LCDs aren't affected by increases or decreases in air pressure. Their performance is consistent regardless of the altitude at which they're utilized.

This is not the case for a plasma TV. The display element in plasma TVs is actually a glass substrate envelope with rare natural gases compressed therein. So, at high altitudes (6,500 feet and above), an air-pressure differential emerges, which causes plasma displays to emit a buzzing sound due to the lower air pressure. This noise can sound rather like the humming of an old neon sign. NEC has been effective in producing several plasma models that are rated to 9,500 feet.

ADVANTAGE: LCD, at 6500 feet and higher.

Pats Opinion: Plasmas have made great strides in this area. There are certain models

that are rated above 6500 feet. Mine operates fine and doesnt buzz at all.

 

LONGEVITY

LCD manufacturers claim that their displays last, on average, 50,000 to 65,000 hours. In fact, an LCD TV will last as long as its backlight does - and those bulbs can sometimes be replaced! Since this is nothing more than light passing through a prismatic substrate, there is essentially nothing to wear out in an LCD monitor. However, one nasty little known fact about LCD technology is that as the backlight ages it can change colors slightly (think of florescent office lighting). When this occurs the white balance of the entire LCD will be thrown for a loop and the user will need to re-calibrate, or worse, try to replace the backlighting or ditch the unit altogether. Some of the early purchasers of larger LCD screens will be learning this tidbit in a couple of years. One thing that I’ve found in this industry, it is not easy to find out whether the backlighting on LCDs can be replaced. Manufacturers are either hesitant to discuss the topic, or they just don’t know.

Plasma, on the other hand, utilizes slight electric currents to excite a combination of noble gases (i.e., argon, neon, xenon), which glow red, blue, and/or green. This is an essentially active phenomenon, so the phosphoric elements in plasma displays fade over time. Many manufacturers state a new half life of 60,000 hours. While I am skeptical of this spec, I do believe strides have been made to nearly even the playing field with LCD. At half life, the phosphors in a plasma screen will glow half as brightly as they did when the set was new. There is no way to replace these gases; the display simply continues to grow dimmer with use.

ADVANTAGE: Even depending upon manufacturer quality.

 

SCREEN BURN IN

LCD technology is not prone to screen "burn-in" or "ghosting" (premature aging of pixel cells) due to the nature of the technologies "twisting crystals."

With plasma displays, static images will begin to "burn-in," or permanently etch the color being displayed into the glass display element. The time it takes for this to occur depends greatly on the anti burn-in technology of the manufacturer. Recent improvements by plasma manufacturers have certainly extended the time it takes to burn in a plasma pixel cell. In the past I was concerned to place a DVD on pause 15 minutes. Now, many of the enhancements such as better green phosphor material, and motion adaptive anti burn-in technology are greatly reducing the risk of burn in. It’s gotten so much better that I don’t even worry about it anymore. In a new model plasma from any top tier manufacturer I would put "ghosting" estimates at an hour or more now (Ghosting can be "washed" out by displaying static gray material). Permanent burn-in I would put at more than 10 hours.

ADVANTAGE: LCD, but not as much of a concern as a year ago.

Pats opinion: Burning is no longer an issue in plasmas. It was in early models but is no longer. I have left mine on pause or even had my pc screen on it with no burn.

 

OTHER CONSIDERATIONS

PRODUCTION SIZE & COST

All television measurements are stated in inches as a diagonal measurement of the display screen from corner to corner.

Both LCD and Plasma televisions are becoming more readily available in larger sizes though plasma still leads the size battle by a great margin. Pioneer and LG produce 61” plasma sizes while Panasonic has a readily available 65” model. Though it is not being imported into the U.S. yet, Samsung has produced a gigantic plasma television of 100 inches. Though such mammoth monitors are expensive, they exhibit none of the "kinks" one might expect with such large displays. In other words, even the largest plasma displays are reliable. Large plasma displays will consume power – try 675 watts for a 65“ display compared to around 330 watts for a 42” plasma although some plasma manufacturers have reduced power intake and made the product more efficient.

The substrate material for LCD TVs has proved difficult to produce in large sizes without pixel defects owing to faulty transistors. Sharp produces one of the largest available LCD displays at 45 inches, while Samsung has a 46” LCD. Sony and NEC currently produce units measuring 40" diagonally. This will change very soon. These manufacturers will have very large LCD screens here this year if production goes as planned.

ADVANTAGE: Plasma by a slim margin. Even though production costs and retail prices have come down for both technologies, plasma still has the edge as far as production cost and capacity go.

 

POWER CONSUMPTION

Not a very important issue but worth noting. Because LCDs use florescent backlighting to produce images, they require substantially less power to operate than plasma TVs do. LCD displays consume about half the power that plasma displays consume. The reason: Plasmas use a lot of electricity to light each and every pixel you see on a screen - even the dark ones. Though plasma manufacturers have improved voltage consumption requirements a plasma TV will consume around a third more power for the same size display.

Advantage: LCD

 

PRICE AND RESOLUTION

LCD displays will have a higher resolution per same size comparison than plasma. The lowest resolution of a 40 inch LCD will be 1366 X 768 – easily full HD resolution in 1080i or 720p. A 42 inch HD plasma has a resolution of 1024 X 768. While this is not truly an HDTV resolution, it’s close enough so that it’s difficult to detect the difference. A 50 inch plasma TV will have an HD resolution of 1366 X 768 and now many also have 1920 X 1080, while a 45 inch LCD displays 1920 X 1080 (1080P) resolution.

Those extra pixels and the production process of LCDs cost more money to produce. Expect to pay a third as much more for a similar size LCD than a plasma TV.

ADVANTAGE: It’s a toss up.

 

CONTRAST / BLACK LEVELS

Plasma technology has certainly achieved quite high contrast ratios, a measure of the blackest black compared to the whitest white. Many plasma display manufacturers boast a contrast ratio of 3000:1 these days though our tests have not proven these numbers out. Panasonic has long been the leader in plasma black levels and we measure contrast of a 42" HD Panasonic plasma at about ANSI 1450:1 - still impressive. Plasma displays achieve such impressive black levels by using internal algorithms to block the power to particular pixels in order to render a pixel "dark" or black. While this can limit a plasma television's gray scaling, it does produce exceptionally black blacks - depending on the manufactured plasma display element (i.e. glass). A plasma TV uses the most power when it is producing full white. As a result, some 2nd tier manufactured brands of plasma TVs have an audible buzz or whining sound when displaying white or very light images.

LCD (liquid crystal diode) displays, by contrast, utilize electric charges to twist and untwist liquid crystals, which causes them to block light and, hence, emit blacks. The higher the voltage passing through the liquid crystals in a given pixel, the more fully those crystals untwist and effectively block light - all of which makes these pixels darker. As opposed to plasma, LCD TVs use the most power when displaying a very dark or black image. This is a difficult process, and despite recent improvements in LCD black levels, only the best LCD televisions (like those produced by Sharp and Sony) have managed to topple the 1000:1 contrast ratio barrier. Recent improvements have brought LCD displays up to the level of plasma. The one continual drawback here for LCD is off axis viewing, when black levels consistently drop.

ADVANTAGE: Closer than a year ago, but still Plasma. LCD TV manufacturers have made great improvements in black levels and in many cases have managed to match the contrast ratio of plasma displays. However, Plasma displays still maintain a clear advantage in this category due to fading blacks when viewing LCDs from off axis. For scenes with a lot of dark and light images shown simultaneously - as with content originating from DVDs, video games, and NTSC TV signals - plasmas still consistently outperform LCD TVs.

Based on the above.
If you count things up...Plasma Wins.

Plasma Vs. LCD
<!-- -->By Shane Buettner   •   May, 2007

They're both sexy slim, and can hang on the wall. But in spite of the similar physical profiles these two technologies are very different, and each has its strengths and weaknesses and they're not necessarily the ones the sales guy at the Big Box Store will tell you about.

Hey Man, Where Are your Priorities?
In general, plasma TVs have deeper, richer blacks and better contrast ratio. Because plasma screens are highly reflective glass, plasmas perform best in rooms with some degree of light control, which certainly doesn't describe the showroom floor you're likely to be trying to evaluate them in. This set of strengths (and weaknesses) is why plasmas are a better choice for those whose viewing priorities are watching movies in a darkened room.

On the other hand, as bright as plasmas can be, LCDs are typically much brighter. In addition, they don't go dimmer as more and more of the screen area lights up, as plasmas certainly do due to power supply limitations. In addition, screen materials are used that are much flatter in texture and lower in reflectivity. This makes an LCD show better contrast in a brightly lit environment. Not only does this make LCDs look better vs. plasma on a showroom floor, it also makes LCD a better choice for someone who will be using his/her flat panel in a brightly lit room and/or watches more casual TV or sports more often.

So remember, the LCDs are going to show better contrast and snap in a brightly lit showroom environment. Although LCDs are getting better, don't get fooled into thinking that high contrast image will carry over when you get home and drop the lights for movie night. Similarly, if you see a plasma in a darkened, high-end demo room don't think the picture will be so punchy if you're watching in a bright room during daylight hours.

Myth Busting: Longevity, Motion Blur and Hot Gas About Plasma
There are two common pieces of FUD (fear, uncertainty and doubt) that proponents of plasma and LCD throw at one another. LCD's mudslinging is primarily geared to indicate that you'll be lucky if the life span of your plasma will allow you to get the set out of the store. Plasma's people will do their best to convince you that if you try to watch sports or any other "fast moving" program material that you'll be seeing so many trails you'll swear you're having an acid flashback. Neither is true.

In the case of plasma's longevity, newer panels are typically rated at 60,000 hours to half half brightness. That's almost seven years- if you have your TV on around the clock- until your plasma's light output drops to half of what it is the day it comes home with you. In other words, if these products get even close to their rated life spans we're not at all convinced that this is a solid reason to buy one technology over the other.

Motion blur in LCDs, if addressed at all in sales lit, is summed up as “response time.” This is only partly true. Early LCDs suffered badly from this phenomenon. Objects in motion showed so much blur they'd practically leave psychedelic trails across the screen. Plasma manufacturers are making a point in demonstrations of showing that LCD still has some vestigial blur, while plasma doesn't. While that's true to the letter, this isn't necessarily a deal breaker. The latest LCDs, despite faster and faster response times, are not devoid of motion blur as plasma is, but often they're fast enough for most people not to be bothered by it. You can read more about this here.

One other myth we haven't heard in a while is the classic about plasmas needing gas "recharges" periodically. They don't. So don't buy an extended warranty to cover gas recharges because there's no such thing!

Burn, Baby, Burn?
This one is in LCD's favor and there's no denying it. Plasmas are prone to "image retention," or screen burn if static images are left on-screen too long. But so were the CRTs we all lived with for decades. Many plasmas are now shipping with technological tools to defeat this once it occurs, or reduce the chance of it happening. The best defense is to avoid burn entirely. This might not be easy if you're a heavy gamer, or even an addicted CNN watcher- the stock market ticker tape at the bottom of the screen has burn-in potential, even now that it's more translucent. If this is you, you know who you are and whether you need an LCD to service your habits. But if you're an average Joe who's capable of being just a little careful, don't worry about it. Also, keep in mind that after the first 100 hours or so, it gets a lot harder for any plasma to burn in.

Where Are You Going To Sit?
Our focus here at Home Theater is on dedicated hobbyists who will be sitting in an ideal position, dead center with their TV. But for those of you just shopping for a TV, this might be a more casual affair entirely. While LCDs are getting better, they are still more sensitive to horizontal viewing angle than plasmas are. As you walk to the side you'll notice the LCD's contrast compress, and the colors go out of whack.

If you've got your coach planted far off to the side of where your flat panel's going to be, look harder at plasma.

Price Vs. Pixels
While this is changing practically as I write these words, LCD was earlier to 1080p than plasma and far cheaper at that hallowed pixel count. Although its value is questionable at lower screen sizes, at 46" or above consider 1080p a valuable upgrade worth paying extra for.

Posted By Heckle on 07 Feb 2009 08:49 PM

Copyright © 2007 PlasmaTVBuyingGuide.com. All Rights Reserved.

From an unbiased site too, right?

Hey it showed LCD winning some. Besides thats why i posted a second article.