Bells and whistles
Increasingly often manufacturers are loading their cameras with advanced features such as electronic or optical image stabilisation, face detection systems, and advanced image processing features that can add shadow or highlight detail to compensate for difficult lighting conditions. Advanced video recording is also becomming increasingly popular.
While some of these features are genuinely useful, others are really just gimmicks. Effective optical or moving-sensor image stabilisation systems are a real advantage, especially on cameras with longer zoom lenses., but be wary of electronic systems, some of which merely set a higher ISO to give a faster shutter speed. These can be misleadingly named with things like "electronic shake reduction". There are very few cameras on the market that are really any good at ISO settings higher than about 400, so boosting the ISO to produce faster shutter speeds can result in seriously degraded image quality. Again, check out sample images taken at a range of ISO settings to see if this will be a problem.
It's hard to find a camera these days that doesn't have face detection, but some systems definitely work better than others. How useful such technology is depends largely on what type of photos you take. They can be handy for social snapshots of people, but landscape photographers will see little benefit.
Electronic exposure-enhancement systems are also something to be wary of. Again, some systems work better than others. Some just amplify or artificially brighten the image in the darker areas of the picture, which again can cause image noise in these areas.
Some recent cameras have added features in playback mode, such as automatic red-eye correction, which uses the camera's face detection software to edit out the red-eye effect that can be caused by the camera flash. This is actually pretty handy, and saves mucking about with image editing later.
Another increasingly popular feature, especially on luxury compacts, is touch screen technology. While this works well on PDAs and some popular mobile phones, on the smaller screen of a digital camera the touch buttons can be small and fiddly, and some are definitely easier to use than others. Features like touch-select focus points are useful, but you also tend to get finger marks all over your monitor, which can make it hard to see in bright sunlight.
A recent feature that is becoming more popular on many compacts and even a couple of DSLRs is the ability to shoot HD video, usually in the 1280 x 720 resolution format, also known as 720p, often with stereo sound or with the capacity to plug in external microphones. Many cameras also have HDMI sockets that allow them to be plugged into the latest HDTVs, for viewing pictures on the large screen. Many cameras advertise "HD output", but remember that for still images this usually means a resolution of 1920 x 1080 pixels, which is only just over two megapixels.
Things you don't need
There are some features that are found on a number of digital cameras that are advertised as benefits, but are in fact nothing of the sort, and this hasn't changed much in two years. Chief amongst these is digital zoom. You'll still occasionally see things like "Over 40x total zoom!" on adverts or packaging, but thankfully more and more manufacturers are downplaying digital zoom, even to the point of having it set to ‘off' by default. Despite attempts to re-package it under names like "extra optical zoom", all digital zoom does is enlarge the centre section of the frame, discarding most of the picture. The results are blurry and lack detail, and are inevitably disappointing. Really, don't ever use it. What's the point of buying a camera with a 10,000,000-pixel sensor if you're only going to use 1,200 of them?
Some other cameras have additional "features" such as built-in MP3 players, or even rudimentary games. If you want an MP3 player, buy an iPod or something. Hybrid products are always a compromise, and seldom perform any of their features as well as a dedicated single-function device so if you want to take good pictures buy a camera that is designed to take good pictures, not one designed to play tunes.
There are probably a few hints and tips I've missed this time around too, so if you've got any buying advice, why not make use of our comments secion on the next page? I'll be sure to add any sensible suggestions in another two years.
The extra bits
Bells and whistles