Why you shouldn't buy a plasma TV

Traditionally, high-end plasma televisions have been considered to be the best the TV industry has to offer. But many LCD manufacturers are now saying that plasma is no longer worth the expense, with large panels often costing twice as much as similar-sized LCD ones.

Tommaso Monetto of Sharp says that despite plasma screens reigning as king of large sizes in the past, LCD panels are now taking over.

Plasma vs LCD

"The debate between LCD versus plasma is a long running one," he told TechRadar. "Technology improvements in image processing, higher resolution and contrast ratio have helped LCD to increasingly become the preferred technology for flat panel displays.

"Through increased picture information on screen, the LCD can now exceed the picture quality of plasmas in large screen sizes. Ultimately, LCD technology is encroaching on the territory of plasma. Developments in contrast ratio technology have also allowed LCD images to compete with plasma by providing unparalleled black levels," he said.

LCD struggles with blacks

In the past, LCD panels have been unable to reproduce the deep blacks we see in the best plasma screens. That’s because LCD panels are transmissive, so each pixel acts as a shutter to block out an ‘always on’ white backlight. Unfortunately as well as needing a continuous power input, the LCD shutter is unable to fully block the light from the lamp, and that often results in a washed out image, particularly in dark, ambient conditions.

But this looks set to change with a new range of LCD TVs set to hit the market in 2010.

Back at IFA in August, Sharp's CEO Toshiyuki Tajima revealed some new prototypes of what he said would be possible to produce at the company’s brand new 10^th generation LCD factories. The 52-inch panels were just 20mm thick, had contrast ratios of 100,000:1 (enabling very deep blacks) and genuine 180 degree viewing angles.

Tajima would not tell us exactly how these stats were achieved, but it’s a fair guess that it was through using two LCD panels on top of each other, instead of just one. That would explain how the TVs were able to filter the light out so effectively.

LCD has the edge?

So it would appear that for anyone looking to buy a new TV, LCD has the edge in a number of areas. For a start you can buy good quality LCD TVs in small sizes, unlike plasma. A good LCD is not as expensive as a good quality plasma. Improvements are being made all the time. And in the future, LCD panels promise to deliver unprecedented levels of quality – although that doesn’t help today’s purchaser.

Energy efficiency is also on the side of LCD. In general, LCD panels consume less power, although this changes depending on certain variables. Plasma panels consume a varying amount of power because when a pixel is black, it’s effectively turned off. So a black and white movie, for example, will consume a lot less power on a plasma because more pixels will be turned off.

The backlight in LCD panels, however, is always on, meaning it’s constantly using up the same number of watts. There are obvious exceptions like the one above but, in general, it’s cheaper to run an LCD TV than a plasma one.

Sharp says that by 2011, LCD TVs will have over 90 per cent of the flatscreen TV market. And when the 10G LCD factories go online in 2010, Sharp will be capable of producing not only very large panels, but also very small ones with 1080p resolutions. That is something plasma technology will never be able to achieve.