Plasma vs. LCD: The State of the HDTV

The ongoing clash between plasma and LCD HDTVs (or rather, their owners) rivals classic tech wars such as Apple versus Microsoft and Nintendo versus Sega in its ability to destroy friendships and alienate loved ones. As with any good tech fight, however, the skirmishes that occur in review comments and home theater enthusiast forums across the Internet are typically characterized by fans exchanging glib one-liners (in this case, about black levels and refresh rates). And many of those one-liners haven't been updated since 2002.

Don't buy a new TV based on outdated information. Here's where plasma and LCD HDTVs stand today.

Blacks, Brightness, and LEDs

Panasonic's 42-inch TC-P42G25 plasma HDTV.
Traditionally, plasma displays have been able to produce higher contrast levels, meaning that their blacks are blacker and their whites are whiter than those of their LCD brethren. This point is particularly important for TV and movie enthusiasts, since you're not going to see too many dimly lit scenes watching Monday Night Football.

It shouldn't matter what you watch, though--in theory, since the human eye has more light-sensitive photoreceptors (rods) than color-sensitive photoreceptors (cones), we're drawn to displays with higher contrast ratios no matter what material we're watching.

The reason plasmas were able to achieve better blacks in the past was that they were better able to control how and where the display was lit than their LCD-based rivals, which used cold cathode fluorescent lamps (CCFL) behind the LCD layer to light the display and couldn't completely block that light out when displaying a black scene.

Enter the LED-backlit LCD, which has made a tremendous splash in the HDTV market over the past two years. LED-backlit LCD TVs have several advantages over CCFL-backlit LCDs: They're thinner, they use less power, and they generate less heat.

For movie buffs, however, the most important feature is "local dimming," which lets the TV selectively turn the LEDs on and off. When an LED-backlit LCD shows a dark scene, it can turn the lighting off in the black parts of the image while leaving the lighting on for the other parts, generating deeper blacks and better contrast.

Of course, how good your screen looks depends a lot on the room you watch it in. Plasmas typically looked best in pitch-black rooms, since the nature of plasma display technology requires a glass screen, which reflects more light than a matte LCD panel. That made plasmas perfect for home theater enthusiasts, but not so great for anyone who watches TV in a room with sunlight or in a mixed-use room where the lights have to stay on.

Sharp's LED-backlit LC-52LE820UN was very reflective in dim lighting.
Sharp's LED-backlit LC-52LE820UN was very reflective in dim lighting.
These days, however, some LED-backlit LCDs use glass panels combined with a glossy coating that makes them just as hard to see in a lit room as any plasma, and in the meantime plasma TV manufacturers have been working to improve their antireflective glass panels. As a result, we can't generalize quite so easily about the two TV technologies.

PCWorld conducts TV testing in a dimly lit room, and we found that the LED-backlit Sharp LC-52LE820UN was horribly reflective, while all three plasmas we tested at the same time (the Panasonic TC-P42G25 and TC-P46G25, plus the LG 50PK950) looked just fine.

The verdict: Plasma diehards may still insist that theirs is the superior technology, and LCD fans may hail LEDs as their savior. When it came down to blacks, viewing conditions, and contrast, though, we didn't find a significant difference between the two display types as a whole, just differences between individual models.

Plasma Burn-In

The 50-inch 50PK950 by LG.
The 50-inch 50PK950 by LG.
Early plasma sets had a problem with "burn-in," where a TV that had shown a static image (a heads-up display in a video game, for example) would continue to show a faint outline of that image after the display had changed to something else. The effect appeared because the phosphors in that part of the display would overheat and lose some luminosity, producing a shadow.

Strictly speaking, burn-in is still possible in modern plasma TVs. Today's plasmas, however, use less energy than those that first hit the market, which means it's harder to overload the phosphors and cause burn-in, especially if you're using the Home viewing mode instead of the Store mode.

Even in-store display models, which often show the same image for a while on the high-intensity Store display mode, almost never exhibit burn-in. You shouldn't have a problem playing games, but it's best to be safe and turn the TV off when you're not using it--your manufacturer's warranty generally doesn't cover burn-in issues.

The verdict: Burn-in isn't as big a deal as it used to be, but it can still crop up. Turn off your plasma set when you're not watching it, and you should be fine--or buy an LCD model to ensure that you won't get burned.

In Video: How to Fine-Tune Your HDTV

Motion Blur and Refresh Rate

"Plasma TVs are better at handling motion than LCDs are." You've probably heard that before--possibly right before you bought your last TV. But what does "handling motion" mean?

Earlier LCDs suffered from a problem called "motion blur," in which the TV would look as if it were struggling to keep up with the fast-moving scenes it was displaying. Several factors contribute to the effect (this Wikipedia article about motion blur is a pretty good resource), but the two primary issues facing LCD HDTVs have been the time it takes for a pixel to change color ("response time") and the number of times the TV refreshes the image per second ("refresh rate"). If the response time isn't quick enough, the TV can't change colors fast enough to keep up with the on-screen action.

Refresh rate, however, is a little more complicated, which is why we have a whole article devoted to sorting it out--read "LCD HDTV Motion Features: How Do They Work?" for more. Suffice it to say, current LCDs don't really have a problem with motion blur anymore, though a new class of image quirks and artifacts accompany the techniques that manufacturers have used to eliminate motion blur.

One thing that the increased refresh rate does is make pretty much everything look smoother. If you view the same panning shot side-by-side on a 240Hz LCD TV and a plasma TV, everything on the LCD TV will look as if it's gliding along, making the plasma seem choppy by comparison.

Whether that gliding effect looks better or worse than the motion on a plasma TV is really a matter of personal preference--dedicated moviegoers probably won't like it (some call it the "soap opera effect," since it doesn't look as cinematic), as it's not quite so faithful to the source material. On the other hand, casual TV watchers might prefer a 240Hz LCD.

The verdict: Motion blur isn't really an issue nowadays. The various engineering techniques used to fix motion blur in LCDs can lead to a few strange image issues, though, and if you don't like the overly smooth look of a 120Hz or 240Hz LCD set, stick to a plasma.

3D Plasma Versus 3D LCD

Whether you have an LCD or plasma HDTV, you'll still need to wear these for 3D TV.
Right now, regardless of whether you choose LCD or plasma, you need to wear active shutter 3D glasses to watch 3D TV. These glasses receive a signal from the TV set (or, in some cases, an external adapter) that tells the glasses to alternate between dimming the left lens and the right lens, while the TV itself rapidly alternates between two slightly different perspectives. This arrangement causes your eyes to see two different images--which makes the image appear 3D.

Since the glasses dim the image considerably, and since the TV has to alternate quickly between two different perspectives, you'll need a bright, fast TV. Otherwise, the image will be dark, and you'll see "ghosting" in the 3D image because your left eye and your right eye aren't seeing images that are different enough to produce a consistently 3D effect.

As you can probably guess, that plays to plasma's strengths, which is why an affordable TV like the Panasonic TC-P42GT25 looks about as good as the Sony Bravia 40HX800 despite the latter's costing nearly twice as much. To show a high-quality 3D image on an LCD, you need the higher-end features, such as LED backlighting and a 240Hz refresh rate, while a standard plasma set can handle 3D just fine.

The verdict: Both TV technologies can produce a good-looking 3D image, but plasmas don't have to work so hard for it. If you want a cheap 3D TV, plasma is the better bet. Read "How to Show Off Your 3D TV" for more tips on 3D.

Still the Same: Price, Viewing Angle, Power Consumption

LG has 50-inch 3D plasma TVs under $1000.
A few things haven't changed between plasmas and LCDs. Plasmas still require significantly more energy than most LCDs do--in our latest HDTV roundup, we found that plasma sets from LG and Panasonic used two to three times as much electricity than most of the tested LCD models did, even LCDs in larger size classes.

You'll find energy hogs on the LCD side of things, too, however--the Mitsubishi Unisen LT46265 LCD used only about 8 percent less power than the Panasonic TC-P46G25, a plasma in the same size class. If you're looking to slash your electricity bill, start by checking our reviews; we post the power-consumption test results in the PCWorld Lab Results section (just click the link that says Show Complete Lab Results, and scroll down to the 'Power Off' and 'Power On' listings.).

Plasmas are still cheaper, as well. A plasma display by a major manufacturer, such as LG, Panasonic, or Samsung, typically costs up to $1000 less than a similarly equipped LCD set of the same size (read "Cheap HDTVs for Black Friday and Beyond" for more on inexpensive TVs). And while LCD TVs' viewing angles are good enough for most living-room setups, plasmas still win out handily in that respect.

In Video: How to Buy a Flat-Screen TV

Buying a TV that meets your needs and fits your budget isn't easy--and if you aren't able to sort out the facts from the fiction, it can get much, much harder. Be sure to read our HDTV Buying Guide and our HDTV Holiday Shopping FAQ for more advice on finding the right set for you.