You don't have to be very old to remember when LCD (Liquid Crystal Display) screens were invented. Today LCD TVs completely dominate the television market. Their nearest competitors, plasma TVs continue to lose ground against them while anything less than a flat screen TV is almost considered quaintly old fashioned.

LCD TVs have come so quickly that most of us have not been able to keep up with the changes. Our LCD TV Buyers Guide will help you understand everything you need to know about them. Then use our TV comparison tools to find the right TV for your needs.

LCD TV technology you need to know

An LCD TV is a television that uses a Liquid Crystal Display screen. Liquid crystal displays are made up of sub-pixels, but unlike plasma screens the LCD sub-pixels don't emit light, they act like a blind allowing light through from a backlight in varying degrees. Colour is produced by filters in front of each sub-pixel to produce red, green or blue.

In order to understand LCD technology in depth, a combined physics and chemistry degree would be required. Fortunately, you really only need to know a few basic facts in order to make a smart decision when you buy an LCD TV. 

Screen Resolution

Screen resolution is a big determinate of the sharpness of an image. It is determined by pixels. If you take a standard digital photograph and enlarge it many times, you see that the image is made up of thousands of tiny squares. Those little squares are pixels. The word "pixel" is an amalgam the words "picture" and "element." The more pixels you have, the sharper the image you will get. To get a good picture image, you need a screen resolution of at least 1280X720. This is easily accomplished, since even most LCD TVs under $500 have screen resolutions of 1366 x 768 or more. For full HD (High Definition) LCD TV, look for a screen resolution of 1920X1080.

Maximum Display Resolution

This is the HD format the screen is able to display in true HD resolution. In the specs, the number is often followed by a letter, such as 'i' or 'p'. The 'i' stands for 'interlaced' while the 'p' stands for progressive. 1080p is considered to be "Full HD Display".

Response Time

While many people know about pixels and their relationship to screen resolution, the response time specification is less widely understood. Response time refers to the rate at which the liquid crystals in an LCD screen respond to a signal and go from white to black and back again. Measured in milliseconds (ms), a response time of 6ms can be found on some high end models, while a maximum of 12ms is the most that a good TV should have. 

Contrast Ratio

The contrast ratio is the ratio between the brightest and darkest parts of an image. In a poor quality image, black images appear grey, while white is blurred. Very good LCD TVs have a contrast ratio of as high as 25,000:1 or even more, while the average set has a ratio of 10,000:1. 

Image Frequency

Measured in hertz (Hz), the image frequency affects the number of images that can be displayed on the screen per second. Entry level LCD TVs have an image frequency of 50 Hz, while better models give twice that number. The "ghosting" effect of a fading image you sometimes see on LCD screens is caused by a low image frequency.

If you are trying to decide between 2 LCD TVs, both of which have the same screen size and other features and are wondering why one costs more than the other, all of the above factors can help you decide which is the better set. You may even find that the cheaper set is a better deal.

 LCD Screen Size: Is Bigger Always Better?

 As LCD technology marched ahead, so did the size of LCD screens. Today, even screens as large as 46" (116cm) are commonly purchased. Should everyone strive to have as large a screen as possible? While it is tempting, you will actually have a better viewing experience if you match the size of your screen to the distance from which you will be viewing the display. As a rule of thumb, follow these guidelines:

• Viewing Distance: .60-1.50 m/Screen Size: 21"-27" (53-68 cm)
• Viewing Distance: 1.8-2.4 m/Screen Size: 32"-37" (81-94 cm)
• Viewing Distance: 3.0-4.0 m/Screen Size: 42"-46" (106-117 cm)

LCD TV Features to look for

 The rapid advances in television technology suggest that when you look for a new television, you should think ahead. While just a few years ago, High Definition programs were rare in Australia, today they are far more common. Many LCD TVs, even some with HD tuners, aren't really capable of giving you the full HD experience. Use this guide to help you get an HD LCD television that you will be happy with for years to come.

3-D TV is no longer just a futuristic fantasy: it is here already. Just as there was only a smattering of HD programs available a few years ago, there are still only a few 3-D offerings available today. 

We use our televisions today with a number of other devices. We have gaming systems, DVD players, home theatre systems, Blu-ray players, digital recorders, video cameras and other devices that can be plugged into the TV. A sometimes overlooked feature in LCD TVs is connectivity. Be sure the TV you buy has plenty of connectivity options. You will probably need them.

Final Considerations

LCD TVs give you such outstanding picture quality that you will probably be disappointed with the sound quality of your television. Consider getting a speaker pack so that you can get the full home theatre experience. 

A home entertainment system with all its bells and whistles is a significant investment. However, you can expect to get up to100,000 hours of use out of a good LCD TV. That's a lot of entertainment value for your money. Most of us would agree that it is money well spent.