FAQs
The Which? guide to getting the best from LCD and plasma TVs. Find out about LCD and plasma TV power use, HDTV and more.
The Which? guide to getting the best from LCD and plasma TVs. Find out about LCD and plasma TV power use, HDTV and more.
LCD and plasma are too new for us to have information about their long-term reliability. Their durability is also a bit of an unknown quantity.
On average plasma TVs use more than twice the power of 32-inch LCD TVs and 2.5 times as much as conventional 32-inch widescreens.
Even when comparing like-for-like in terms of screen size, on average plasma TVs use around 50% more energy than similar-sized LCD TVs.
However, some manufacturers point out that the power use of a plasma TV is directly dependent on picture brightness, whereas an LCD TV picture requires a constant source of illumination.
The theory goes that a plasma TV should use less power over time. But in reality plasma TVs require significantly more power to achieve the same brightness level as an LCD TV, putting something of a 42-inch widescreen hole in the theory.
The smaller the screen, the less power it uses. On average, a 26-inch LCD TV screen uses less than 90 watts when switched on and costs £13 a year to run. A 40-inch LCD TV uses almost 100 watts more power and costs twice as much to run.
Most LCD and plasma TVs can be mounted on walls. However, most don't come supplied with the wall mounting kits required.
These have to be bought separately and (depending on the size of your TV) can cost anything up to £300. Most TVs and kits match the VESA standard - a set of industry-wide measurements.
No. You could buy an integrated digital TV (IDTV) with a built-in digital tuner to receive Freeview (digital channels through your normal aerial). Go to our digital switchover page to find out more about Freeview and the different ways to receive digital TV.
Cable quality can influence sound and picture quality on LCD and plasma TVs. Poor-quality Scart cables are more prone to interference from other devices and atmospherics. But you don’t have to pay the earth – a tenner should do, rather than opting for the cheapest at three or four quid.
A good rule of thumb – the thicker the cable the better. This usually means it boasts more ‘screening’ from interference. Also look for gold plated connectors.
Occasionally plug and unplug the cables in your LCD or plasmaTV. This helps to remove the build-up of oxides, which affect how well signals are transmitted.
Screen burn is where a ghost image of a channel logo is left on the screen once the set has been turned off or onto another channel. The problem doesn’t affect LCD TVs but plasma TVs and old fashioned CRT TVs are susceptible.
However, broadcasters have toned down the brightness of their logos and the latest plasma TVs boast screen-cleaning technologies to combat the problem.
In the Which? tests, images burnt on to the plasma TV screen after a day, disappeared after normal TV viewing. After leaving a channel logo on screen for a week only one plasma TV (out of six tested) suffered any permanent screen-burn.
The LCD and plasma TVs in the Which? tests haven't shown this problem. Internal speaker output is properly aligned with the pictures on screen.
We’ve occasionally found some discrepancy when linking LCD and plasma TVs up to external loudspeakers in the laboratory, but this wouldn’t be apparent in everyday use.
HDTV is much sharper and more detailed than regular TV and boasts more realistic pictures. It's available either via Sky or Virgin subscription packages. Alternatively you can pick up a couple of HD channels on the new BBC/ITV Freesat service, without the monthly payments.
Whatever digital platform you choose, to watch high definition you'll also need a high definition TV. Look for the official HD-ready logo when buying an LCD or plasma TV - this guarantees the minimum screen resolution and digital sockets needed to watch HD broadcasts.
HDTV pictures come in two main formats - 1080i and 1080p. The four-digit number tells you how many horizontal lines make up the picture, and the letter shows how it's broadcast. The 'i' means the picture is 'interlaced' and sent to the TV in two sequences, one after another, and the TV meshes them together. Almost all HD broadcasts are in 1080i.
However, most high-definition DVD players use the 1080p format. A 1080p picture is sent in a single sequence making the picture sharper than 1080i - but the difference is very subtle.
You can, but you probably won't be getting the very best high-definition picture possible. Many HD-ready LCD and plasma TVs can't process a 1080p signal, so will switch to a 1080i picture when used with high-definition DVD.
Ideally the LCD or plasma TV should also display pictures, or frames, at the same rate they're recorded on to high-definition discs (24 frames per second). If the TV doesn't process at the same speed, the result can be juddery movements during fast-motion or camera-panning scenes. The HD-ready logo guarantees neither 1080p, a high screen resolution, or 24fps.
Which? has come across some LCD and plasma TVs that make no specific claims of 1080p/24 but still work with high-definition DVD rather well (like most of our Panasonic LCD TV Best Buys). This is purely down to the superior picture processing software, which can make up the difference if certain specifications are lacking.
Look for LCD and plasma TVs with the new HD-ready 1080p logo - this guarantees 1080p output, 24fps and a high screen resolution of 1920x1080. It increases the chances of getting the best possible high-definition DVD picture but is not an absolute guarantee.
Labels like Full HD or 1080HD are not part of an official standard, so meanings differ between manufacturers. Some can process a 1080p signal, others have a high screen resolution of 1080 horizontal lines (1920x1080), some do both.
Not many process at 24fps, so shockingly they're no guarantee that your LCD or plasmaTV will work properly with the latest high-definition DVD players.
In the absence of the official HD-ready 1080p logo, check for labels like this. Sony, Toshiba and Pioneer are among the first to release new high-definition LCD and plasma TVs and DVD players designed to match the speed of Blu-ray and HD-DVD discs and they all use the 24fps logo.
The Sony D3000 LCD TV, opposite, does not match the requirements for the HD-ready 1080p logo (the screen resolution is too low) but it does support 1080p/24 and works with high-definition DVD without any motion judder.
Screen resolution of 1,920x1,080 is certainly preferable for high definition sources, but it’s neither essential nor a guarantee of a great picture.
Plans are afoot to launch HDTV channels on terrestrial Freeview – many technical issues have been resolved and there’s even a chance it could happen over the next couple of years.
No. IDTVs will need another decoder (or set-top box) to receive terrestrial or Freesat HD signals. Terrestrial digital will in that respect be no different to cable or satellite digital, which also require another decoder box. Of course, the TV has to be HD-ready to display HD programmes.
No. If terrestrial HDTV is launched, standard definition content will still be broadcast in the same way. So your current IDTV or set-top box will be able to receive signals as normal. However, they probably won't be able to receive terrestrial HD signals.
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