Desktop monitors buying guide
What's the single best upgrade you can buy for your PC? It's not a new processor or a graphics card, it's a great big widescreen monitor. Just make sure you get one that's good.
How are monitors measured?
Like TV screens,monitors are defined by the length of the diagonal line that runs across the middle of the panel. Standard sizes are 22- and 24-inch, although there are an increasing number of huge 27- and 30-inch screens available too.
Are monitors the same resolution as TVs?
Most monitors now use the standard HD TV resolution of 1920x1080 pixels, like a 1080p TV. The similarities end there, though. Because monitors tend to be smaller, pixels are more tightly crammed together for even sharper picture quality when you're looking at one close up. Plus, they tend to have more accurate colours.
What should I look for when choosing a monitor?
The two key characteristics to look for when buying a monitor are the response time and contrast ratio.
- Response time - that's the time it takes for a pixel to change colour, measured in milliseconds. The lower this number is, the less likely it is that you'll see motion blur and ghosting in a moving image or game. The fastest monitors have a response time of just 2ms.
- Contrast ratio - contrast ratio tells you the difference in illumination between black and pure white in a screen. The larger the ratio, the blacker the blacks, the whiter the whites and the richer the colours between. Watch out for 'dynamic contrast ratio', though. These artificially boost the figures by changing the brightness of the backlight depending on the scene. It's a trick that works, but overall image quality is often not as good.
What's the best combination?
It depends. Expensive monitors with a high contrast ratio and excellent image quality have lower response times because of the way they are made, using a technique called 'In Plane Switching' or IPS. Cheaper monitors, which use 'twisted nematic', or TN, technology actually have much lower response times, but the picture quality isn't as good. Gamers who want fast screens might buy TN panels, while photographers who want colour accuracy will want IPS. IPS screens also have better viewing angles.
What are VA panels?
They're somewhere in between TN and IPS screens, with decent - but not amazing - response times and contrast ratios.
What else should you look for?
Just as important as any of this are the design basics. A screen with an adjustable stand that can be set to a comfortable height is much more comfortable to use, and you might want one with an HDMI port or TV tuner built in so you can connect a set-top box or games console for other forms of entertainment too.
Can computer screens do 3D?
Some can. They use the same principles as 3DTVs, so you'll need a compatible screen and a pair of active shutter glasses. You'll also need to make sure that your PC is capable of outputting 3D images too.
- TFT/LCD - TFT and LCD are really just two ways of talking about the same technology. All modern flatscreen computer monitors are LCD screens, but the types of LCD filters - TN, IPS and VA - do make a difference.
- LED - monitors with an LED backlight are thinner and less power hungry than ones with a traditional bulb inside.
- DVI - the standard interface and cable that runs between a PC and a monitor.
- VGA - many monitors still have an old fashioned VGA port, which was the analogue standard for PC screens before DVI came along. Some laptops only have VGA outputs, so if you want to hook them up to a larger screen than the built in one, you'll need a monitor with a VGA in.
- HDMI - many computer monitors also have the TV standard HDMI port. As well as being able to use them to play on a games console or use an HDMI Blu-ray player or set-top box, it means you can also connect them up to the new generation of Android tablets which often have an HDMI output.
- DisplayPort - the newest type of monitor connection is called DisplayPort. It uses smaller cables than DVI or HDMI, but offers more bandwidth for higher resolutions. Not many PCs or monitors have DisplayPort adaptors yet, though, although it is commonly found on Apple Macs.
- Viewing angle - with older LCD screens, there was a real problem with viewing angles. If you weren't looking straight on at the centre of the picture, often the image would distort or go grey at the edges. Modern monitors are less likely to suffer from this problem.