LCD vs plasma TVs

Differences between LCD and plasma TVs

LCD TVs

Liquid crystal display (LCD) screens come to life when light from behind the screen is shone through the screen's matrix of tiny coloured liquid crystal cells. Signals control each cell, letting varying amounts of colour through, and a picture is built up.

Plasma TVs

A plasma TV display is an array of tiny gas cells sandwiched between two sheets of glass. Each cell acts like a mini fluorescent tube, emitting ultraviolet light which then strikes red, green and blue spots on the screen. These spots glow to build a picture. 

Collectively the two technologies are often called flat-panel TVs.

Screen size

LCD TV now offers the widest-array of screen-sizes but for many years huge 37-, 42- and even 50-inch plasma TVs were the only choice for fans of big-screen TV. Technology restricted LCD TVs to small portable sets and the 32-inch market.

Today, it's a different story. Massive manufacturer investment in research and production has led to LCD TV screens becoming increasingly bigger. Many manufacturers have abandoned plasma altogether (such as Sony, Sharp, Toshiba) and LCD screens are now common in the 40-inch plus category.

VERDICT: LCD TV

Picture quality 

The million dollar question, which flat-panel technology actually looks better on the screen? There are a couple of general observations to be made; many LCD TVs don't do blacks well, so darker pictures can look washed out and plasma TVs typically have wider viewing angles.

But in reality the issue is less to do with the hardware and far more to do with the digital processing software inside the TV. Both LCD and plasma TVs have to upscale and de-interlace TV pictures, and instead of scanning them directly onto the screen like a CRT they store pictures and place them onto the screen a frame at a time.

The quality of the digital processing software used to hide the side effects of all this, not the technology per se, will more often than not dictate the quality of the picture.

Having said that, LCD TVs have the definite edge over plasmas in the rigorous Which? testing regime and find most favour with our exacting viewing panel. However, if you take screen-size into account this is hardly surprising.

A 26 to 32-inch screen is the optimal size for watching standard-definition material. Bigger screens tend to make digital processing side-effects more obvious. Conversely, bigger screens are more suited to high-definition. A 42-inch screen is more capable of showing-off the extra detail and sharpness of a HD picture, than a 26-inch set for instance. 

Considering most of us watch standard-definition TV, LCD is more often than not the technology of choice. In larger screen sizes Sony and Toshiba LCDs vie with Panasonic and Pioneer plasmas for top spot

See detailed brand overviews for the lowdown on all the leading TV manufacturers. 

VERDICT: LCD TV shades it

Power consumption

Based on our test results a 42-inch plasma TV typically uses 277 watts when switched on, compared to an 180 watt average for the 40-46-inch LCD TV category. That's 50% less energy than plasmas.

However, some manufacturers point out that the power use of a plasma TV is directly dependent on picture brightness, whereas an LCD TV picture requires a constant source of illumination. The theory goes that a plasma TV should use less power over time.

But in reality plasma TVs require significantly more power to achieve the same brightness level as an LCD TV, putting something of a 42-inch wide-screen hole in the theory. See 'Use less electricity' for some energy saving tips. 

VERDICT: LCD TV wins hands down

Versatility

Both LCD and plasma TVs can be wall-mounted. However, wall-mounting kits usually cost extra and cost more the bigger the TV. Plasmas weigh a lot more than LCDs (even those of comparable screen-size), so setting them up or moving around could prove problematical. 

VERDICT: LCD TV

Cost of LCD and plasma TVs

Prices have plummeted for LCD and plasma TVs in general and cost is now much less of an issue than it was. LCDs tend to be cheaper purely because of a smaller average screen size. 

However, 42-inch plasma TVs for under £1,000 are now easy to come by. Prices for comparable screen sizes are now pretty similar. 

VERDICT: draw