If you are looking for a big screen TV, then you are probably debating between plasma, LCD and perhaps a rear projection television. Just a few years ago, plasma was the frontrunner in big screen TV, but recent advances in LCD technology have made that format the frontrunner in sales. Does this mean you should follow the pack and get an LCD TV? Does plasma still have advantages over its rivals in the big screen television department? Review our buying guide to find out the pros and cons of Plasma TV.

How Does Plasma TV Work?

Imagine millions of tiny fluorescent lights all stacked together to form a large rectangle. Now imagine each of these divided into groups of three - a red one, a blue one and a green one. Call each of these little groups a pixel. Each colour in each of these pixels responds to an electrical signal by shining more or less brightly depending on the colour it is being told to produce. By this seemingly simple process, these pixels can produce billions of different colours.

Those little "fluorescent lights" are the plasma. Plasma is actually the gas that illuminates a fluorescent light, so the analogy is accurate. We'll skip the physics of just how this gas creates illumination for now. The important thing to know is that, unlike cathode ray TVs, which create visible lines due to a scanning process, each pixel of a plasma screen has its own transistor electrode. This is why you get such a wonderfully smooth image with plasma televisions of any size.

Advantages of Plasma TVs

We've already hinted at some of the advantages of plasma TVs. Here's a recap of those plus some other ones:

High Resolution: The combination of the enormous spectrum of colours plasma can produce, the tiny size of the pixels and their unique ability to act as individual transistors creates an image that practically defines "High Resolution." Plasma sets are easily capable of displaying full HD (High Definition) signals.

Amazingly Accurate Colour: If you have ever dabbled in art, you will know that the difference between a good painting and a great painting is in the artist's deft use of colour. With its limitless pallet of colours to choose from, a plasma TV can produce breathtakingly realistic colour images with a depth of field that is almost 3-D. Also, plasma is able to display the polar opposites of black and white more effectively than any other systems. This adds to its ability to produce such a crisp picture.

No Flicker or Scan Lines: Whether you consciously notice it or not, a cathode ray television tube (CRT) flickers. After you have seen plasma, you will appreciate the difference the absence of flicker makes to your viewing experience. The same thing applies to scan lines.

Wide Screen Capability: Wide screen is defined by something called aspect ratio. This ratio of 16:9 was not pulled out of a hat: it corresponds to our natural field of vision. Plasma TVs were designed around the wide screen format so that viewers could enjoy a true home theatre experience. This is a two-edged sword, though, because normal television has a 4:3 aspect ratio and engineers have had to develop ways of adapting to it. Some have succeeded better than others (see disadvantages).

Uniformity of Brightness: For years, plasma's biggest competitor in the big screen market was the rear projection screen. Plasma gained ground over that system because its picture never has those bright "hot spots" that show up on its competitor's screens. The brightness level is uniform throughout the length and breadth of the screen.

Wide Viewing Angle: LCD TVs produce a distorted picture when viewed from an angle. In contrast, you can view a plasma picture almost from the side of the screen as well as you can from directly in front of it.

Great for Dark Room Viewing: Plasma TVs are superior to CRT and LCD in this respect, eliminating the glare the contrast between light and dark produces in those formats. The flip side of this coin is that LCD is better in bright light conditions (see disadvantages for more about this).

No Magnetic Field Interference: If you have a sound system near an LCD TV, the magnetic field generated by speakers can distort the picture unless you get speakers with magnetic shielding. Plasma TVs do not have this disadvantage, so you don't need to trade in your existing speakers if they are not shielded.

Disadvantages of Plasma TVs

If plasma televisions were perfect, they would have no competitors. However, as close to perfect as technology has come in recent years, it hasn't gotten there yet. These are some of the disadvantages of plasma TVs:

The Wide Screen aspect ratio we mentioned above makes plasma an ideal way to view wide screen motion pictures in your living room. However, when your favourite show comes on, the set has to adapt to the 4:3 aspect ratio of normal television. Engineers have accomplished this in various ways. Sometimes it is done simply by blacking out the sides of the screen to make the picture fit in its original aspect ratio. Other times it is done by presenting the whole picture, but cutting it off at the edges. Finally, engineers diddle with the algorithms of an incoming signal to try to adapt it to the 16:9 aspect ratio of plasma screens. This has had mixed results, with some resultant stretching or distortion of the image.

As mentioned above, plasma screens are much better for viewing in a dark room than either CRT or LCD sets. However the same thing that makes them superior in a dark room makes them less effective in a brightly lit room. Their colour fades somewhat and they reflect more of the light from external sources. In a room with dimmer ambient light, plasmas and LCDs perform equally well.

Plasma TVs are expensive. At the lower end of the market, expect to pay up to double the amount of an LCD TV if you want a plasma television. Things tend to even out more in the high end models. In between, at the $2000-3000 level, manufacturers and dealers are fighting the onslaught of LCD by offering some great deals. For example, a 50" (127 cm) model with plenty of features was recently offered for just under $2500. If you are looking for a great big screen, HD television and are more concerned about its price than its format, check out our "Best Deals" on both LCD and Plasma TVs. You will be surprised and delighted by the fierce price competition that is going on between the two formats.

The Final Verdict

Frankly, we don't have a final verdict to offer. In our opinion, though, if you are looking for an HD TV with a screen size over 42" (106cm), we suggest you look at both plasma and LCD before you make your own final verdict. Keep in mind your viewing preferences. Do you like watching in a darkened or a well-lit room? Do you prefer HD or are you choosing a television mostly for watching your favourite TV shows? Do you have speakers that are not magnetically shielded? As our Buying Guide explains, these are important factors to consider.

When it comes to smaller screens, we believe that LCDs probably offer better value than plasma televisions. This is especially true with screens less than 32" (81cm). There are fewer plasma TVs to choose from in these ranges and they cost more than their corresponding LCD TVs.

Finally, don't stress too much about your decision. Remember, it was only a few years ago that neither Plasma TVs nor LCD TVs existed. Whatever you choose, it will give you years of viewing pleasure.