Beginner's Guide to Buying an HDTV: Plasma or LCD?

If you're in the market for a new flat screen HDTV, there are basically two types of technology to choose between - LCD or plasma. Both are capable of supporting high-definition images and each has its own strengths and weaknesses – but which is best for you?

Plasma panels were the first flat screens to arrive in the mainstream at the turn of century. Simply speaking, the underlying technology relies on chemical compounds called phosphors. Each pixel is constructed from three phosphors displaying Red, Green and Blue (RGB) primary colours. When struck with an electron beam these phosphors emit light that can be controlled by the beam's intensity to create images on screen.

In recent years LCD has dominated the HDTV market primarily because they are less expensive to manufacture – with some big name brands like Toshiba and Sony ceasing plasma production altogether. Unlike plasmas, LCDs don't actually emit any light themselves. Instead, they use millions of crystals suspended in liquid between two transparent panels. A bright fluorescent backlight is then passed through the crystals, which are instructed to allow it or prevent it from passing to create an image while colours are controlled by a filter.

It used to be that LCD was reserved for small screen sizes while plasma was used for screens larger than 37in. But, LCD has grown in size and stature and models can be found in practically any size right up to 100in and above – offering more flexibility, especially if you want a smaller screen for a second room. LCDs generally weigh less as they don't use the same gas filled chambers and heavy glass panels as plasmas, which might influence wall-mounting options.

Although LCD dimensions have grown, prices have fallen and they are generally less expensive than plasma screens. The average price of a 42in LCD is around £1200 while a same sized plasma costs around £1700. The latest models from both technologies claim to offer around 60,000hrs of watching, which translates to 20 years worth if you watch four hours every day, so you don't have to worry about life span. But, if you're concerned about the environment, plasmas typically consume slightly more energy than LCDs as they don't need to power thousands of electrons to stimulate phosphors.

Without much separating the two technologies in terms of design, features and price, it's subtle differences in performance that really distinguish them. It's difficult to say if one technology is necessarily better than the other as they feature different picture characteristics, which means it comes down to personal preference.

LCDs are renowned for higher resolutions (with more Full HD 1080 models available) and a brighter picture courtesy of the backlighting technology, which means they also perform better in bright rooms. While bright images expose more detail and make colours appear instantly engaging they bleach black levels, which dilutes depth-defining contrast while colours can seem superficial. Although recent models have been improved, even when an LCD pixel is switched off light emitted from the backlight escapes leaving blacks a dark shade of grey steals solid definition from the picture.

As plasma pixels can be controlled to emit no light at all they produce deeper black levels, which creates better contrast and grey scale subtleties, which reveal more detail in dark picture areas and create more cohesive gradations during shadowy scenes. Plasmas also produce more natural and accurate colours with a wider range of subtleties across the spectrum. Some people prefer more realistic images while others favour the exaggerated but vibrant colours that LCDs offer – it usually depends on what type of films you watch.

Plasmas are generally thought to cope with movement more naturally too, especially with difficult slow camera pans or scrolling text – although recent improvements in LCD technology using advanced response times means that the difference is less pronounced than it used to be.

It's really a case of what you prefer but recent European research has found that 73% of consumers using a large screen display preferred the image quality of plasma to LCD. Now that you've got all the facts, try visiting a retailer where you can see both types of screens and decide

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