IT Reviews has recently updated its Buyer's Guides. If you're looking for information on business and home movie projectors, check out our dedicated guide to projectors here.

Your monitor is, by and large, one of the most important parts of a PC. While a processor gets used for heavy number crunching, and a powerful graphics card is a necessity when you're gaming, the monitor is the thing you'll be using all the time - along with the keyboard and mouse, of course. Make the wrong choice, and your suffer from sore eyes and painful wallet. But don't worry: ITReviews is here to talk you through the potential pitfalls involved. We'll also take a look at even bigger-screen entertainment with a digital projector.

It's important to make sure that you buy the right monitor. While there are plenty of bargains to be had, make sure you get one that's right for your needs: at the lower end of the market, a difference of just £10 can separate a truly terrible monitor from a high-quality bargain.

Screen size
When shopping for a monitor, the first thing to bear in mind is size. As with TVs, the size of a monitor is measured in diagonal inches - although if you're shopping from bargains within continental Europe, you might find diagonal centimetres used instead. Unless you're strapped for space, don't consider anything less than a 17in model - and, ideally, look for a 19in version instead.

Aspect ratio
The next thing to consider is aspect ratio. While the now mostly defunct CRT (Cathode Ray Tube) type of display tended to mirror a TV's traditional aspect ration of 4:3, modern flat-panel monitors opt for a more cinematic 16:9 aspect ratio. If you're buying around the 19in mark, you'll likely have a choice of 16:9, 16:10, or 5:4. If you mainly use your monitor for watching films and gaming, the 16:9 widescreen option is perfect. For more business-like use, a 5:4 monitor allows you to see more of a webpage or document without scrolling vertically.

Resolution
Finally, look at the resolution - usually expressed as the number of pixels available both horizontally and vertically. The higher the figures, the greater the number of dots that are squeezed onto a single screen - and the greater the detail the display is capable of showing. Higher resolutions are good for gamers, as they make the graphics appear that much more realistic, but you'll need to make sure you've got a powerful enough graphics card to drive the display. For film buffs, a 1920x1080 - sometimes called 1080p - display is perfect, as it matches exactly the resolution used in Full HD TV broadcasts and high-definition video content such as Blu-ray discs.

Connectivity
Once you've narrowed your choice of monitor down to one that matches what you need in size, aspect ratio, and resolution, check its connectivity. Those buying a monitor for an older PC will likely need a VGA connector, also known as a D-Sub or HD15, but this old analogue connection is becoming increasingly uncommon at anythign but the budget end of the market. If you're planning to watch films, look for a monitor with an HDMI or HDCP-compliant DVI port - you'll need it for Blu-ray playback. For those with newer Macs or AMD graphics cards, monitors with DisplayPort connectors - while rare - are a good investment.

As with any purchasing decision, the market splits into three definite categories: budget, mainstream, and premium. Each bracket has clearly defined differences in terms of features and quality, so pick to your spending power and see what is out there.

BUDGET
As a budget buyer, you haven't much much to spend - but the good news is that the cost of a high-quality flat-panel display has dropped in recent years, and you don't have to spend a fortune to get a decent screen that you can easily watch films and play games on.

If you're on a budget, the chances are you're looking at the 17in to 19in end of the market - and it's here that the aspect ratio question is most important. Despite having the same diagonal measurements, a 19in 16:9 widescreen display has significantly less viewable area than a 19in 5:4 display - so you may find that if you want a decent widescreen monitor, you're better off picking a size above that which you had intended.

The majority of displays available at the budget end of the market feature 'thin film transistor', or TFT, technology. TFT is a technology which greatly improves the performance of liquid crystal displays, helping to minimise motion blur - vitally important for gamers. Most use a cold cathode backlight, which provides a bright picture but typically poor levels of contrast - in particular, black levels aren't the best.

You won't find any DisplayPort monitors at the budget end of the spectrum. Instead, expect to have to choose between a single VGA connector or a single DVI connector - although if you shop around, you may find some models that include one of each.

Budget monitors lack the features of their more expensive brethren, such as dynamic contrast, energy-efficient LED back-lighting, and swivel stands that allow the monitor to be operated in portrait or landscape modes - but they do often come with built-in speakers. Sadly, these are usually tinny, and distort at high volumes. For anything other than office work, you'll want to invest in a separate set of speakers.

For a 19in display with reasonably fast response times and a good contrast ration, you can expect to pay less than £70.

Tags: cathode ray tube liquid crystal display display device hardware peripherals displays tft lcd digital light processing