The A490's overall performance isn't too bad for a budget compact. It starts up in a little under two seconds, which is fairly brisk, and shuts down again in about two and a half. Its shot-to-shot time in single shot mode is a bit slow at approximately three seconds, which in continuous shooting mode it can manage a shot every 1.8 seconds, but it can at least keep it up indefinitely.
The autofocus system is a bit slow by Canon's usual standard, often taking over a second to lock on, and the shutter will fire before focus is confirmed, which means that it's quite easy to take out-of-focus shots if you're a bit too quick on the trigger. Even more surprisingly for a Canon camera low light focusing is very poor. It is slow, and often won't achieve focus in light that's bright enough to read a restaurant menu by. The AF assist lamp is pretty feeble and only has a useful range of about a metre and a half.
Battery duration obviously depends on the type of AA batteries used, but Canon claims approximately 150 shots using standard alkaline batteries, and the performance of my review sample seems to bear this out.
Overall image quality is actually surprisingly poor. The lens is reasonably sharp from corner to corner, but it does produce significant wide-angle distortion and there is also noticeable chromatic aberration towards the corners of the frame. The level of detail recorded is surprisingly low even for a 10MP camera. Colour rendition is very vivid to the point of garishness, and which dynamic range is actually pretty good it does still have a tendency to burn out highlights. Image noise isn't quite as well handled as most of Canon's other cameras either. There is visible noise from 200 ISO upward, although colour rendition remains fairly consistent until the maximum of 1600 ISO.
The Canon PowerShot A490 is a cheap camera for those on a tight budget who still want the prestigious brand name, but its overall build quality, performance and image quality don't really compare to Canon's more expensive models. There are much better cameras available for just £20 more.