Posted 9 December, 2003

A few years ago Liquid Crystal Displays were found only on laptops or very expensive systems. These days, they are a reasonably priced alternative to the older Cathode Ray Tube monitors. As a relatively new technology there a few things to watch for when buying an LCD display.

What size?

Like all displays, go for as much as the budget affords. There is little weight and size difference between smaller and bigger LCD screens. So a desk that would have trouble squeezing a 17" CRT onto it will easily fit a 17" LCD.

One big difference between the technologies is that you get more viewable screen on an LCD. So a 15" LCD gives you a bigger screen than a 15"CRT.

Resolution

Get an LCD that has comes in the screen size you use. Unlike CRT screens, LCDs come in a fixed resolution. You can change that resolution, but some LCD screens don’t like this at all.

Computer specifications

Be careful about the age of your computer. Large screens are hard work and older computers often don’t have enough memory to deal with them. Check that your computer has the video memory to handle the demands of the monitor.

DVI connector.

Some displays have DVI connections, these are quicker than the standard analogue connections normally used on computers. To take advantage of it, your computer needs a DVI output. If your computer has the right equipment you should consider a DVI, otherwise don’t bother.

Brightness and contrast

Brightness and contrast are important selling points to vendors. The higher the contrast ratio and brightness the better. But be careful, the manufacturers are notoriously unreliable with their claims about these features.

Black and white pictures are the best way to judge the quality of contrast. This is why dealers often play cartoons to show off their cheaper LCDs so you don’t see the black and white. On the other hand, fast moving cartoons can be an indicator the monitor’s response time.

Response time.

Also known as known as the refresh rate (this is one of the differences with CRT displays.) Most displays come between 16 and 25ms. It’s difficult to spot the difference, but the lower you can get the better.

Defective pixels.

These are the biggest complaint of LCD buyers. An LCD screen contains over a million pixels. Some will be defective. If you are buying the screen from a shop, test it in the shop. If you’ve ordered directly then check for defects as soon as you receive the monitor.