ASDA & George Information and Services
Customer aiding information
|How do I buy the TV set-up that’s right for me?|
|Flat screen TVs are much cheaper than they once were and have all but replaced the traditional television. They're also slimmer, slicker and compatible with both Digital TV, High Definition and, in increasing number, 3D Television.
While the television industry is working hard to standardise TV viewing, there are still a wide range of options to consider when choosing your home entertainment set-up, and with big events such as the World Cup looming, there is no better time to get clued up and this guide is here to help.
|Types of TV Screen|
|With the number of types of TV now available, how do you know which one is right for you? Let’s take a look at the features and advantages that each type offers.|
Plasma TVs are older than LCD TVs and are made from hundreds of tiny cells of gas that can change colour to make the images on the screen. They're generally heavier than LCD TVs, and ten years ago were probably the only choice for screens larger than 32 inches. Due to these larger screen sizes they have traditionally been more expensive than LCD TVs, however this hasn't been the only reason for the extra cost. Plasma TVs are seen as desirable because they offer wider viewing angles than LCD TVs (which generally must be viewed from a more central viewing position). Meanwhile, LCD TVs must be backlit continually to be seen which means they can never display true black, so Batman's costume will never look as black as it should be. Plasma TVs can achieve a 'truer' black colour.
Advantages • Larger screens • Truer Colours • Wider Viewing Angles
The screens used in LCD TVs are those typically used in computer monitors. Their pixels are tiny liquid crystal pouches that change colour. They are backlit by a sheet of light and electrical signals allow different levels of light to come through. They are significantly lighter than Plasma TVs and are therefore easier to mount, store and move. There is some debate over whether their picture quality can match those of a Plasma TV, although tests suggest that there is little practical difference and that the picture quality is far more dependent on the technology inside the box than the display screen. Other consumer tests carried out by x have shown that there are power differences between LCD and Plasma TVs - with LCD TVs proving far more efficient over short periods of time.
Advantages • Cheaper • More efficient • Lightweight
The most recent and exciting development in television is 3D TV. Most TV manufacturers are developing TV Screens capable of the 3D experience you’ve probably already seen in cinemas – and the big-hitters like Samsung, Panasonic, Sony and LG hope that 50% of all their TVs will come with 3D technology by 2012.
There’s a lot to be excited about: all the major broadcasters are launching 3D TV Channels (Sky’s 3D Service began broadcasting in April 2010), while many 3D TVs are capable of converting your favourite 2D broadcasts and recordings into 3D images (although these will not be quite as realistic as made-for-3D TV programmes). If you haven’t yet seen a HD football match on a 3D screen… well, we pity you.
How does 3D TV work?
We’re born with two eyes – meaning our vision is made up of two images at slightly different perspectives, and this difference is interpreted by the brain as depth. Traditional telly shows us one flat image and the difference is lost, but 3D TVs cleverly show two images, a different one for each eye, using either a filtering or a shuttering method.
Watch the TV image on the right hand side, it shows how glasses are used to filter two simultaneous images into different eyes.
In cinemas, a filtering method is used – two images are projected simultaneously and those ‘attractive’ plastic glasses filter the correct image to each eye. 3D TVs use a slightly more advanced process. Rather than showing us two images at the same time, they change (or ‘refresh’) between what the right eye and the left eye should see. In this case, the 3D glasses use liquid-crystal shutters in the left and right lens that flicker in time with your 3D Set. Of course, all of this happens too quickly to notice – but the advantages include better colour and an improved image quality with none of the trace or ghost image you might be able to see at the cinema. The disadvantage is that the glasses are slightly more expensive – but still a fraction of the TV’s overall cost.
Advantages • Works without glasses (but basically it doesn't yet exist!)
LED TV screens are not a new type of TV screen but a type of LCD screen that's backlit differently either to improve picture quality (this is called RGB Dynamic LED TV) or to make the television super slim (Edge-LED TV). They’re generally more expensive and seen as more desirable, not least because they come with lots of extra features common in modern TVs such as web compatibility and full HD.
Edge LED TVs use a method of backlighting that cater for extremely thin screens. The screen is lit from the side by a bank of LED lights, and the light is spread across the screen to produce a superb uniform colour range. This means that you don't need the bulky flourescent backlight found in 'traditional' LCD screens, which in turn means super slim TVs!
RGB Dynamic LED TV
Normal LCD TVs are backlit by a single panel of light that’s always on. This means that dark scenes don’t look properly dark and subtle detail is hard to see. You might not be able to tell the difference between a very dark brown and black, for example. To solve this problem, RGB Dynamic LED TV screens are lit by hundreds of individual lights called LEDs or Light Emitting Diodes which can be turned off in patches to make truly dark colours where needed on the screen.
The example on the right shows how nearly black (left) and true black (right) versions of the same image can affect the quality and presentation of the picture. It is easier to see subtle detail with true black. The backlight on Dynanic LED TVs, like the one shown in the graphic on the right, can be dimmed locally to produce a better quality of black.
|A few things to look for:
As well as choosing between the types of screen available, most customers will think about a few key features before choosing a TV: screen size, resolution, contrast ratio and refresh rate. All of this information can be found in the product description and features of each TV on Asda Direct, and will help you find the TV that suits both your performance requirements and your budget.
|Screen Size...||Resolution...||Contrast Ratio...|
|Measured from corner to corner. HD looks spectacular on a large screen.||Standard Definition, 720 or 1080 HD, see the next page for details.||TVs with high contrast ratios show a richer, more colourful picture.|
|Refresh rate ...|
|The refresh rate is measured in hertz (Hz) and is used to indicate how many times a second the image on your TV is scanned and recreated. This is important for creating a smooth-looking picture during action scenes on a large screen. 50 Hz (the image is refreshed fifty times a second) is clear enough, but some modern screens offer 100Hz and upwards, which makes action seem incredibly smooth and lifelike.|