How to buy a high-definition LCD TV

LCD technology has been around for decades, but only recently has it come to the forefront of home entertainment through flat-panel televisions.

Despite talk of a battle between LCD and plasma for high-def viewing supremacy, LCD has the most popular segment of the market all to itself, with the 26-inch and 32-inch screen size too small for plasma to credibly challenge in.

But competition is still fierce, and there are a huge range of models to choose from. Fortunately this is good news for you, as more competition means better prices.

1. The case for LCD

Although most of the truly big flat-screen TVs are plasmas, LCD is constantly pushing those boundaries, and there are now several 52-inch LCDs on the market.

As the more established technology, LCD televisions tend to be cheaper than plasmas of the same screen size, and the technology itself is more conducive to supporting 1080p, or Full HD, images.

Brightness and colour depth tend to be more vibrant than plasma, but LCD has traditionally suffered from less impressive contrast ratios and difficulties in dealing with moving images.

2. 1080p or not 1080p?

A television labelled 'HD Ready' is capable of receiving and displaying a high definition signal, either from another piece of equipment like a DVD or Blu-ray player, or from a digital broadcaster. The resolution must be at least 720p - meaning 720 vertical lines of resolution and 1,280 horizontal lines through a method called 'progressive scan'.

Sets capable of 720p can also handle an alternative type of broadcast delivering 1,080 horizontal lines and 1,920 verticle, but through a lower-quality 'interlaced' method. This is called 1080i. In practice, the two offer similar levels of picture quality.

1080p is similar to 1080i in that it delivers the same 1920x1080 signal, but through progressive scan. This equates to a significant jump in quality, and is typically labelled 'Full HD'. In practice, however, you're unlikely to notice the difference on anything less than a 50-inch screen, and at present all HD programming is broadcast at 720p anyway.

3. Start your engines

With competition among LCD manufacturers so high, each company makes a big deal of any picture processing technologies on board, giving them exotic names that are in stark contrast to the drab monikers of the TVs themselves.

It's not unheard of for such internal wizardry to actually make a picture look worse instead of better, so check for some product reviews before committing to buy a television. Just because the technology sounds clever doesn't mean it is.

Picture processing is a constantly advancing science, and what may seem an attractive deal may be so well priced simply because it contains an older version of a company's picture processing engine. That shouldn't necessarily put you off, but make sure you know what you're buying.

4. The right connections

Your TV does not exist in isolation, and will typically be hooked up to a Sky box or similar, as well as some kind of disc spinner and possibly an AV amp or speakers. The quality of signal your television displays can only be as good as the cable carrying it, so connectivity is a vital consideration before buying.

HDMI is the ideal connection for HD signals, and most class-leading sets feature three HDMIs these days. Component video, RGB Scart or S-video are the next best, while Scart and composite video should be seen only as a functional way of connecting older devices to the screen.

5. Recommendations

There are typically about three times as many LCDs on the market as plasmas, and competition is extremely fierce, particularly in the key 26-inch and 32-inch markets.