TFT Flat-Panel Monitors

When you're buying any new hardware for your computer, there's always a baffling array of acronyms and jargon to get to grips with. Flat-panel Monitors are no different. In this section, and the sections that follow, we'll take a look at what to pay attention to when searching for a new flat-panel monitor. In the final part, there's an exercise to have a go at, with some real monitor specifications. First up is Contrast Ratio and Brightness.

Contrast Ratio

A Ratio is a measure of how much of one thing you have compared to another. For example, How much sand do I need compared to cement? A Ratio of 6 to 1 will then mean 6 parts sand to 1 part cement. Or 6 times as much sand as there is cement.

For computer screens, there is a thing called Contrast Ratio. The Ratio this time is how much brightness compared to darkness. So it's the difference between the whites and the blacks. A typical 19 inch TFT monitor will have a Contrast Ratio of 700 to 1. The higher the Contrast Ratio the sharper and crisper the image should appear. So look for bigger numbers here.

But you shouldn't base your buying based purely on Contrast Ratio. This is because of something called Brightness Rating (see below). If you have a high Contrast Ratio but a low Brightness Rating then the whites in the image won't look as good as the blacks, and the image may look a little dull.

In general, though, with a good Contrast Ratio, the blacks should look black and not grey.

A Greyscale Image

In the image above, you should have a nice deep black on the far left, fading to white on the right. Contrast Ratio is the difference between the blacks on the left and the whites on the right.


Brightness Rating

This is often referred to as Luminance. It's how bright an object is. For monitors, it's how bright the image looks on the screen. The measurement you'll see here is usually in Candelas per square meter (CD/m2). In the US, you may see the term Foot-Lamberts (FL) used.)

You should generally go for a high brightness number: The higher the brightness number, the easier it will be to see the image on screen on sunny days, outside, or when the screen is in direct sunlight. For a 19 inch monitor look for CD/m2 value of about 300 to 400.

Brightness and Contrast Ratio tend to go hand-in-hand.


In the next part, we'll take a look at the importance of monitor resolution, and also see what response times are. You'll see both of these mentioned when buying a new monitor, and they are important.

The Native Resolution of a Monitor -->

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