Sales staff often use screen resolution and contrast ratio figures to impress customers. However, LCD and plasma TVs all use digital processing software to put a picture on the screen. Unless it’s spot on, this process, known as ‘up-scaling’ and ‘de-interlacing’, can lead to unpleasant side effects. Instead of being wowed by the ‘higher the better’ numbers orthodoxy, use your own DVDs, with some of the scenes suggested below, and try these simple approaches to get a better idea of the LCD or plasma TV's real picture quality.
LCD and plasma TV reviews: How to buy LCD and plasma TVs
Tips for buying the best LCD or plasma TV
Sales staff often use screen resolution and contrast ratio figures to impress customers. However, LCD and plasma TVs all use digital processing software to put a picture on the screen.
Unless it’s spot on, this process, known as ‘up-scaling’ and ‘de-interlacing’, can lead to unpleasant side effects.
Instead of being wowed by the ‘higher the better’ numbers orthodoxy, use your own DVDs, with some of the scenes suggested below, and try these simple approaches to get a better idea of the LCD or plasma TV's real picture quality.
Picture quality on LCD and plasma TVs
Check the source of the picture you're watching in the TV showroom – LCD and plasma TVs in stores often screen HD pictures. While this demonstrates how good HD can be, it's certainly not representative of the picture quality you'll get via a standard broadcast signal or DVD.
Something plugged into the HDMI socket at the rear of the LCD or plasma TV is a dead giveaway that you're being shown high-definition images.
Common problems with LCD and plasma TVs
Edges
Watch out for over-enhanced edges on images, such as buildings or text. High-resolution LCD and plasma TVs sometimes over-sharpen pictures, leading to jagged lines.
Reflections
Keep an eye out for screen reflectivity. LCD TVs tend to reflect the least – plasma TVs aren't quite as good.
CRT TV screens are made of glass and tend to reflect more light than both LCD and plasma televisions
Colour banding
When watching something like a sunset on your LCD or plasma TV, instead of different shades of colour subtly blending into one another, colours appear in distinct bands.
Smearing
A ghost-like effect, often visible on moving images. You’re unlikely to spot this on LCD and plasma TV displays showing simple colourful images – cartoons, say – so watch a football match instead.
Picture judder
Like smearing, this is more easily spotted on real life fast-moving action and panning shots. Images fail to move smoothly across the screen, instead making slight stuttering and juddering movements.
Black levels
LCD TV pictures often look a bit washed out. Check out a movie with very dark sequences, like The Matrix, and see how much detail you can pick out.
Colour-fade
The colour on some LCD and plasma TVs starts to fade when not viewed head on. LCD TVs are particularly susceptible from acute angles (see illustration, right).
Extras
Budget for the extras – most of the LCD and plasma TVs in the Which? test can be wall-mounted, but none come supplied with the necessary brackets.
Universal wall-mounting kits can cost around £40 to £200 but your new LCD or plasma TV's guarantee may only cover brackets bought directly from the TV manufacturer.
It's worth getting the TV profesionally mounted, otherwise your warranty may be invalidated.
You won't get dramatic improvements in picture quality by splashing out on expensive cables.
Avoid the cheapest – and pay about £10 for a decent Scart (to connect to standard-definition equipment, such as DVD players) and £20 for a high-definition HDMI cable (to connect to a HD box).