LCD or Plasma

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.

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.

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.

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.

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.

Plasma

LCD

Size and weight

Generally larger than LCDs, with screens up to 71 inches. Plasma TVs are usually around 10% heavier than LCD screens (meaning great care should be taken when mounting on a wall)

Usually no larger than 46 inches, though larger TVs are in development. LCDs are often slightly thinner than plasma TVs.

Quality of Picture

Usually plasma screens have better contrast. Both have excellent quality and sharpness.

LCD usually has a slightly clearer picture in smaller models and a higher resolution.

"Image Burn"

Nowhere near as much of a problem now as a few years ago, there is still a slight concern that images left still for a long time could be etched into the screen.

This is not a problem with LCD screens.

Viewing angle

Plasma tends to have slightly better viewing angles than LCD.

Some models have a restricted viewing angle, but many allow up to 160-degree

Brightness and glare

In a fully dark room, plasma TVs have better contrast and brightness than LCD screens.

LCD TVs generally reflect less light and glare, so fare better in normal light conditions

Lifespan

Usually, plasma screens last for up to 60,000 hours before they dim by half (Panasonic last until 100,000 hours)..

LCD TVs usually last 60,000 hours or more before they dim by a half.

Energy usage

Plasma uses slightly more power than LCD screens. Panasonic have reduced the consumption of their screens by 30%.

LCD TVs often use less power than plasma screens. They can consume 60% less power than a CRT television