How to choose between plasma, LCD or LED

The days are getting shorter, the NHL hockey season is well underway, and the last of the leaves are falling from the trees which means Canadians are spending more times indoors and more time in front of their televisions.

If your first-generation high-definition television (HDTV) or aging tube television has a given up the ghost then you may be thinking about shopping for a new flat-panel television for the living room or family room this holiday season.

In the HDTV marketplace today, there are three types of flat-panel technologies to choose from: LCD, LED, and plasma.

For the budget-conscious consumer who is looking for the biggest screen for the buck, I recommend an LCD television. Thanks to its low cost, decent picture quality, and long life (typically 60,000 to 100,000 hours), LCD is far and away the best-selling flat-panel technology.

However, the more discerning high definition (HD) television buyer – who's willing to spend a little extra for superior video quality – should consider buying a plasma television.

Plasma vs. LCD

To understand why plasma technology is superior to LCD, we first need to have a rudimentary understanding of how each technology displays video images on a screen.

Plasma displays are described as a self-illuminated technology because images are created by lighting up individual pixels on the screen. A plasma display consists of millions of phosphor-coated glass cells or pixel containing plasma. Each pixel has three cells (one for red, green and blue respectively) therefore a 1080p plasma display panel has over 2.7 million pixels (1920 x 1080) and 8 million cells on its surface. To produce an image, electric current flows through the screen, causing certain bubbles to emit ultraviolet rays which trigger the phosphor coating to produce red, green or blue.

LCD, or Liquid Crystal Displays, are described as a transmissive technology because rather than self-illuminating each pixel, images are created by passing fluorescent light through a series of polarizing filters in order to generate various colours. LCD's weakness is that it can't always shut out all of the fluorescent backlight which leads to a less than perfect video image.

The different way images are produced leads to four primary reasons why video experts prefer plasma over LCD:

1. Superior colour reproduction – because plasma images are self-illuminated rather than created by white light being imperfectly passed through a series of polarizing filters, plasma delivers a wider colour gamut and more dynamic colours.
2. Superior black levels – The richness of an image simply cannot be conveyed if the colours are washed out because of poor black levels. With poor black levels, shadow areas look gray and washed out, making the picture look flat and unrealistic. Plasma can achieve superior black levels by turning off unnecessary pixels where LCD gets blacker by applying a filter which blocks most but not all of the light. LCD inabilities to fully block the light means that even the best LCD panels can only reproduce a dark gray as opposed to black.
3. Better viewing angles – With LCD televisions, as you move off-centre, contrast levels fall. At a 45-degree angle, contrast ratios for an LCD televisions drop 80%. To witness this phenomenon, simply stand in front of an LCD television and slowly move to the side of the room. As you move away from the centre the image will appear more washed out, This is because more light is spilling through the side of the filters. With plasma, the contrast ratio is constant regardless of the viewing angles so the picture looks great no matter where you are sitting in the room.
4. Improved clarity – Plasma trumps LCD in picture clarity for two reasons: First, as we just covered, the improved viewing angles of plasma mean no washed out images. The second reason for greater clarity is plasma's faster response times. Slow response times mean that fast action onscreen can lead to a trail or shadow effect as something moves quickly across the screen. A hockey puck, for instance, will have a momentary trail when it is shot. Plasma's faster response times mean the absence of trails or shadow effect.

LED: The Superior LCD

Over the last several years, LCD manufacturers have gone to great lengths to improve the quality of their sets with the biggest improvement being the introduction of LED (Light-emitting diode) backlighting.

The primary benefit for consumers of using LED illumination for backlighting an LCD panel is to improve black levels. The superior black levels that LED lighting provides give the viewer a sense of greater depth in the image along with more vibrant colours.

Additional benefits from LED backlighting are reduced power consumption, longer bulb life and much thinner LCD panels. Most new LED driven panels are less than one inch thick.

LED vs. Plasma

In side by side comparisons conducted in a home-theatre-type environment, the superiority of Plasma or LED technology over LCD technology is readily apparent to even the most casual observer.

Personally, I still prefer a top notch Plasma over a top-of-the-line LED panel for two reasons: Panel Speed and image consistency. While the refresh speeds on LED panels have virtually eliminated motion artifacts over the years, I can still see ghosting on 3D images on LED panels that are not visible on top-quality plasma panels. In addition, because plasma can literally turn 8 million pixels or zones off and on versus just 8 or 16 zones for LED, I find the brightness levels and contrast more consistent with plasma. These differences, however, are extremely subtle and probably won't even register with the bulk of viewers.

For many consumers, even those that can quickly spot the superiority of plasma over LCD, the difference in image quality between LED and plasma will be virtually indistinguishable therefore the decision to pick between LED and plasma will probably be more a function of price and secondary features such as 3D, Internet connectivity and design.

Hugh's Favourites

There are many good excellent televisions to choose from this Christmas. For top-notch picture quality, my personal favourites are the Panasonic VT Series of plasma televisions and the Samsung 8 Series of LED television.

In the popular 55-inch size, the Panasonic TC-P55VT30 plasma television currently sells for about $2,600 while the Samsung UN55D8000 sells for about $2,800.