A plasma television screen consists of hundreds of thousands of gas capsules filled with natural gases such as neon, xenon, etc. These 'cells' are covered in phosphor and locked tight in a glass plate that is equipped with electrodes. Using electric impulses, these cells emit light that make the phosphoric layer light up in red, green or blue, thus producing any colour.
An LCD television screen uses liquid crystals between two glass layers. When the power is switched on, these crystals let through a certain spectrum of the white light that comes from a lamp behind the glass plates. Every crystal gets the right colour by blocking certain spectrum of light.
Burn-in
Burn-ins remain a problem for plasma televisions. A burn-in means that a certain image remains visible on the screen, even after shutdown. This occurs when there are non-moving images on your screen, such as a scoreboard or the logo of the selected TV post. More recent plasma televisions seem to have less burn-ins, and, they will also disappear after a few hours if there are other images projected. By the way, any television, including LCD or older models, can have burn-ins.
The most recent television also use a technique called pixel shifting. This technique keeps moving the image a few pixels, so one pixel does not always have the same colour projected, diminishing the chance of a burn-in.
Lifespan
There used to be a lot of complaints about the lifespan of LCD and plasma televisions, but times change, and so do televisions. Both the new LCD and plasma screens should work for about 60 000 hours before losing half their brightness, which is the standard for measuring television lifespan. If you watch 7 hours each day, 60 000 hours should keep you running for 23 years. This 23 years only goes for the lifespan of the screen itself, not the electronics surrounding it. It would be quite surprising if these electronics would survive for 23 years.
Brightness
LCD televisions have a higher brightness than their plasma counterparts, making them the better choice in strong surrounding light, which is an advantage in violent-lighted stores, but less needed in living rooms. This makes a plasma television a slightly better choice for normal users.
But, in contrary to plasma televisions, LCDs do not reflect external light. Although these two problems, brightness and reflection, are being fixed in the newest models.
Contrast
Much more important than brightness is contrast, the difference between the lightest and the darkest colours a screen can produce. Contrast creates depth and details in images. Plasma televisions are able to produce extremely deep black colours, which is still a problem in LCD televisions. This is possible because of certain so-called 'algorithms' (computer programs) in the plasma screen which switch off the power for ceratin pixels, preventing them from having any colour, and thus making them black.
LCD screens use electric impulses that place the liquid crystal in a certain direction so that they block the light from the lamp behind them. The higher the voltage of that impulse, the darker the black colour is. In scenes with a lot of dark colours, LCD television use a lot of power, whereas plasma televisions barely use any.
Colours
Plasma televisions can easily show more than a billion colours, mkaing them slightly better than LCD televisions. And of course, more colours mean more realistic images.
Another thing that should be mentioned is the angle in which you look at the screen. This does not make any difference for plasma screens, since every pixel creates its own light. For LCD televisions however, sharp angles can deform the colours. This is because the light that causes the colours is generated by a single lamp.
Images on a LCD television look less sharp and have less contrast if looked at from the side. This makes plasma television thé favourite for sport bars and public spaces where everyone needs to have a clear view, no matter where they are sitting.
But, again, for living rooms this does not really matter, since most people are sitting in an angle not more than 30°.
Response Time
These days, you often hear about the word(s) 'response time'. The lower this response time is, the less smudge effects you will notice. A low response time combined with advanced screen techniques and 100 hertz image changes should reduce these effects strongly, but they are not excluded. This is because LCD was originally developed to project static and not dynamic images.
The response time is irrelevant for plasma televisions, since every pixel in a plasma television is a single entity, capable of switching colour extremely fast.
Resolution
LCD television have a larger resolution than plasma televisions of the same size. 42" sets come with 720 lines, but 1080 is the minimum if you want your television to survive for at least five to ten years. That's the maximal resolution for HD television: 1080 lines of each 1920 pixels wide. LCD television are equipped with HD starting from 37" formats, but then you'll need to be sitting right in front of the screen to enjoy the quality completely.
But resolution alone does not mean quality. The image processing and other processing techniques determine the quality of your image.
Energy Consumption
A LCD television has an almost constant energy use, since the lamp constantly uses the same amount of power. However, the energy consumption varies for plasma televisions. It will use much more energy when displaying bright scenes. A dark movie is way less energy-consuming than a news report shot in a violent-lighted studio.
Summary
Plasma television
- high contrast
- wider angle
- faster response time
- perfect for movies in dark chambers
- better for scenes that hop between dark and light or videogames
LCD Television
- better presentations in violent-lighted rooms
- high resolutions in smaller screen models, ideal for computers and games
The differences between these two technologies have gotten smaller than before, though when people ask to compare the two, most of them prefer plasma televisions.
