Choose the right gear for high definition
Submitted by: Ian Morris
Tip 2: Choose the right TV
Making sure your new TV is HD Ready may be less of a challenge these days, but choosing the right HDTV to meet your needs can still be tricky. With LCD, plasma and rear projection to choose from, your purchase will probably come down to one of three factors: size of screen, budget and usage.
Jump to: LCD TVs | Plasma TVs | Rear-projection TVs
LCD televisions
Currently the most popular HD displays, LCD panels are usually produced in sizes between 15 and 46-inches, although 50-inch and even 65-inch models have reached the market. The problems that used to haunt LCD are becoming less dramatic with each new generation, with wide viewing angles, faster response times and better contrast. Virtually all LCD screens now also come with integrated Freeview tuners, which are essential as analogue switch-off approaches.
The technology
Electricity is passed through millions of tiny liquid crystal molecules. This instructs the crystal to let varying amounts of fluorescent light through from the back of the screen. Red, green and blue filters are then controlled individually to create thousands of different colours.
Pros
• LCD TVs do not suffer from burn-in, so you can leave the same image on-screen for as long as you want
• If the backlight on an LCD fails, it can be replaced (although it may be more economical to buy a new TV)
Cons
• LCDs typically have a lower contrast ratio than other HDTVs, meaning blacks can appear grey
• LCDs also usually feature a comparatively low response time, resulting in smearing during fast-moving action
Plasma televisions
If your main consideration is getting the biggest screen you can afford, then plasma is still the obvious choice. Picture quality is still up for debate though -- some prefer the warmer, more natural appearance of plasma, while others prefer the sharper and more lively colours of LCD.
The technology
A plasma screen uses a panel of three individual fluorescent lights for each pixel -- one red, one green and one blue. By varying the intensity of each colour, the display can produce the full range of colours.
Pros
• Plasma TVs are large and relatively cheap. The most popular size is 42 inches, which can be found for around the same price as a similarly sized LCD
• The contrast range -- meaning blacks can be very rich -- tends to be better on plasma, and have a slightly better viewing angle
Cons
• Leave the same static image on a plasma for any length of time and it will burn permanently into the screen
• Plasmas aren't made in smaller sizes -- very few 32-inch models exist
Rear-projection televisions
Aside from the improved picture quality, the main reason for upgrading to a high-definition display is that it is flatter than a CRT and therefore uses much less space. In comparison, projection TVs lose some appeal due to their greater depth than LCD or plasma, although they are still shallower than CRTs and a few can even be hung on the wall.
Projection TVs offer a much more 'cinematic' picture than flat screens, with a high-contrast image that's very similar to that of traditional CRT. They also usually offer the best 'pound per inch' conversion rate, meaning they're a more economical way of buying a huge screen. The only problem is that projector bulbs need to be replaced after around 2,000 hours, meaning you incur more costs in the long run.
The technology
Most of the projection TVs that we've reviewed have been based on the world-conquering DLP chipset from Texas Instruments. In the chipset, each pixel is a tiny mirror that moves between the 'on' and 'off' state to reflect light through the lens. A colour wheel then rotates to match the colours with the corresponding action of the mirror, at a rate quick enough to be indistinguishable to the eye -- although some people can see a 'rainbow' effect as a result of this process. This image is then fired on to one or more mirrors before being displayed on a high-contrast screen.
Pros
• Projection TVs tend to produce a natural, filmic picture quality that's more suited to movies than a flat-panel display
• In terms of screen size and cost, projection TVs are a very cheap way of getting a large-screen TV
Cons
• The bulb in the projector typically has to be replaced every 2,000 to 3,000 hours, often at a cost of £200 or more
• Rear-projection TVs are not flat, so cannot be hung on a wall (a couple of models excepted)
Submitted by: Ian Morris
Ian Morris is CNET.co.uk's resident expert on all matters relating to televisions, DVD players and PVRs. He loves high definition because, he says, "It's the future of television, offering the sharpest and smoothest picture for the ultimate home-cinema experience."
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