LCD vs Plasma TVs Buying Guide
- — 06 February, 2009 18:33
What is an LCD TV?
LCD stands for Liquid Crystal Display. Liquid Crystal is an amazing substance that reacts when you pass electricity through it. It is normally transparent but when you add an electric current it turns black. The way LCD TV works is that millions of tiny dots each have Liquid Crystal in them and behind each one there is a little circuit that controls the electricity flow. Every second, millions of dots turn on and off and a light shines through them from behind. The dots that are still transparent allow light to pass through and the ones that are black block out the light. Just on top of each dot are three colour filters which change the colour of the light and produce the colours you see when watching.
What is the difference between an LCD TV and a plasma TV?
Plasma is different to LCD as it doesn’t have a light that shines from behind but instead produces its own light from within each dot. Instead of Liquid Crystal, each dot has a small pocket of gas which lights up when you run electricity through it. It also has the colour filter on top as well to produce colours. The advantage of plasma over LCD is that the colour black looks better but the dots are usually a little further apart and you can sometimes see the spaces between them. The result is that the images can look a little blocky. Also plasma uses more power to run and can get pretty hot (enough to heat up a small room).
Do LCD TVs come in large screen sizes, like plasma TVs?
LCD TVs come in a range of sizes up to about 65-inch screens. But if you compare a similar sized LCD and plasma, generally the plasma screen will cost a few hundred dollars more.
Can I also use an LCD TV as a computer monitor?
Yes. Many TVs come with a connection at the back to plug in your computer but they generally don’t support really high resolutions like computer monitors do.
Are all LCD and plasma TVs also HDTVs?
No. In order to be a High Definition television it needs to have a minimum of 720 horizontal lines. Anything below this number is a Standard Definition television. The way to tell whether the TV you are looking at is HD is to look for a figure called the "native resolution". This is the number of lines of dots that the TV has vertically and horizontally. Most high definition LCD TVs are 1366x768 which means that they have 1366 vertical lines of dots and 768 horizontal lines. Plasma televisions can have many different types of resolutions but as long as you make sure that horizontal (second) number in the "native resolution" is over 720, you can be confident that you have bought a true HDTV. Some manufacturers say the TV is HD when really they are stating that it will play HD. In those cases when you play HD on a TV with less than 720 horizontal lines, everything is converted to Standard Definition so you are not really watching HD at all.
Will an LCD/plasma TV work with my old VCR?
Yes. All you have to do is plug it in and it will work fine. However, you should probably be aware that VHS probably won’t look as good on an LCD or plasma television as it does on your old CRT TV.
What else do I need for my LCD/plasma TV?
Most LCD TVs come complete out of the box but some plasma TVs don’t come with speakers so you may have to purchase them separately. If your new TV doesn’t have a built-in digital TV or HDTV tuner, you may need to buy a set-top box which will allow you to watch digital TV.
What do I need to know about getting my TV home myself?
All flat panel televisions are fragile devices. If you are going to transport it yourself, make sure that you pack it well and that it can’t slide around in your car. LCD TVs are a little sturdier than plasmas but they don’t have glass over the front of the TV so you should be careful that you don’t scratch the surface when setting up. When taking a plasma TV out of the box, make sure that you have enough people to carry it comfortably and try not to twist the panel as it can damage the TV. You should also take care to follow any transport and handling instructions on the box and/or supplied by the manufacturer.
What is CRT?
CRT stands for Cathode Ray Tube. It is the technology that has been in use in televisions until flat panel televisions were invented in the 1990s. Televisions based on CRT have a limited number of horizontal lines and hence cannot do High Definition. The way the technology works is that a small device at the back of the television shoots a beam of electrons (microscopic particles) at the glass at the front of the TV. This glass is coated in a material that lights up when the beam touches while another layer on top of that creates colour. The beam is moved backward and forward extremely fast using magnets, creating pictures on the screen.
What is Rear Projection?
Rear Projection is another type of television where a small projector sits in the back of the TV and projects the image onto the screen at the front. The projectors can be LCD however the more popular type is DLP (Digital Light Processing). LCD Rear Projection TVs shoot the light through an LCD panel which creates the image on screen. DLP Rear Projection shoots coloured light at a series of mirrors which create the image. Rear Projection TVs have the advantage of being much cheaper than flat panels but they are very large and you will need to have a lot of room in your home if you choose to buy one.
What is Overhead Projection?
Overhead Projection is where a projector is permanently mounted on the ceiling in a room. Again, these projectors can be either LCD or DLP, although DLP is becoming more popular these days. A dedicated projector will require a separate good quality screen either mounted on the wall or on a floor stand. A properly prepared wall or projection surface may also be suitable. Naturally this takes up less room than an LCD, plasma or rear projection TV because the projector is on the ceiling, out of the way, and the screen is very thin and usually wall mounted.
What is a flat panel?
Flat panel refers to any thin television technology. Flat panels are generally thin enough to be mounted unobtrusively on a wall. The two types of flat panel televisions are LCD and plasma.
What is LED?
LED stands for Light Emitting Diode and is a type of technology that has started to appear in some televisions. It creates much better contrast, blacks and colours than older technologies. At the moment there are only a handful of units on the market employing this technology and they are not cheap, but the results are worth it. Given time we should see more and more become available.
Does lighting in the room affect the type of TV I should buy?
You should only be concerned if you have a room that has a lot of windows or ambient light that cannot be blocked. Regular or fluorescent lighting won’t effect how most televisions look, and generally it can be turned off. Rear projection and plasma will have problems if there is too much ambient light in the room. Rear projection can look washed out if too much light falls on the screen and since plasma televisions have glass over the top of the screen, light can be reflected, making the image hard to see. An LCD television would be your best choice in this situation.
What is the difference between Digital TV (DTV) and regular (analogue) TV?
Analogue television is lower in quality than digital TV. Digital TV is ghost-free in widescreen and offers features that analogue does not. Analogue television signals can be degraded severely by the simplest of things. Did you know that if you have a lot of trees in your area they can cause ghosting in your analogue TV picture quality? Digital TV doesn’t have this problem. If you are in an area that supports digital TV, it will always be high quality.