Lab

Digital cameras

Digital cameras are getting more sophisticated all the time - huge megapixel ratings, enormous zooms and comprehensive manual controls are becoming common on cameras costing as little as £200. But does everyone really need all of these features?

With a complex camera, you can spend so much time capturing a moment that you forget to experience it for yourself. This is why the perfect camera for casual users shouldn't just take great pictures - it should take them with minimal effort. Point-and-click doesn't mean a basic camera, it means one that's sophisticated enough to take perfect photos without you having to manually intervene.

The big picture

When we assess a camera's image quality, we look for two key ingredients. First, we try to produce the best possible pictures, shooting under bright light with a tripod, taking care to optimise the camera's various settings. Second, we also test it in tougher conditions - handheld in low light, using the flash at close proximity, shooting portrait shots against a strong backlight and so on. These situations make life harder for cameras, but they're common ones that the best models take in their stride.

We still welcome manual controls if they're included in addition to a capable automatic mode. An aperture-priority mode lets creative photographers to adjust the depth of field, allowing them to keep the entire composition sharp or to draw attention to a specific part by blurring the foreground and background. Shutter priority lets them choose between sharp images or capturing some motion blur to express movement in a photo, while manual exposure gives direct control over both functions.

Manual exposure is rare for a £200 camera, but all the models on test include manual ISO speed control, white balance and exposure compensation. These functions are more commonly used to fix problems than for creative effects, and as such we prefer to be able to leave a camera in automatic mode. Even so, it's worth knowing what they're for and when they're useful.

Let there be light

Different types of light - sunlight, light bulbs, fluorescent tubes and camera flash - produce slightly different colours. We're so used to this that we barely notice it, but when shooting in light from a light bulb, for example, a camera must work out whether everything looks yellow because the light source is yellow or just because you're photographing a daffodil. It's not an easy feat to pull off and to their credit, most of the cameras on test handled this challenge well. However, some occasionally struggled, giving a colour cast to pictures.

It's usually possible to fix things with the white balance presets (which tell the camera what kind of light you're shooting in), but it's preferable not to have to bother. Bright- or dark-coloured subjects and complex lighting conditions can also confuse cameras, giving under- or over-exposed images. Again, it's fairly easy to remedy this using exposure compensation, if you can be bothered to experiment with it.

Against the grain

ISO control involves a trade-off between two problems - blurry or grainy images. When there's plenty of light, the camera can use a fast shutter speed and still gather enough light to produce a clean, sharp picture. However, in gloomier conditions, the camera must either use a slower shutter speed, which risks causing blur due to camera shake, or take an under-exposed picture and boost the exposure digitally after capture. The downside of this second technique is that errors are boosted too, which manifests itself as increased graininess or image noise.

Cameras often use further processing to reduce noise, but this invariably reduces fine details too. Noise reduction kicks in automatically with higher ISO settings - the higher the ISO value, the faster the shutter speed, and so the more noise you can expect.

Once again, we like cameras that can manage their ISO speed automatically to give optimal results in any given situation, but the best cameras suffer from less image noise in the first place, making higher ISO speeds possible without sacrificing image quality too much.

An alternative workaround for low-light photography is optical image stabilisation. This uses gyroscopic sensors inside the camera to detect camera shake and a moving lens element or sensor to counteract it. The upshot is that it's possible to use longer shutter speeds without resulting in blurry pictures, but it only offers a bit of extra leeway and isn't a miracle cure.

Image quality is our greatest concern when reviewing a digital camera, but there are plenty of other factors to consider. Compactness and durability are especially important in a point-and-shoot camera, as casual snappers will want to slip it into a bag or pocket. Battery life and performance are important too, as a great camera is no use if it's too slow or too flaky to keep up with you. Straightforward controls are welcome, with the most important features close to hand. Ultimately, the camera should also represent good value - is the package worth the price?

With these criteria in mind, we set out to find the best sub-£200 camera on the market, and found more than one fantastic model.