White Balance

The A520 has five white balance presets (sunny, cloudy, incandescent, fluorescent, fluorescent H) in addition to the default auto white balance. There is also a 'custom' white balance setting, which allows you to point the camera at a white or gray object and set the white balance manually. The custom white balance setting is remembered even if you turn the camera off. In normal outdoor shooting the auto white balance works perfectly (as confirmed by our studio tests). Indoors it's a bit more hit and miss, as we've seen with most Canon PowerShots, fluorescent lighting doesn't cause much of a problem, whereas incandescent (tungsten) lighting causes a fairly strong orange color cast. Best to stick to the preset (or one-push custom WB) if you want more neutral colors.

Outdoor - Auto WB
Red 0.1%, Blue 0.5%

Fluorescent - Auto WB
Red -0.2%, Blue 0.4%
Incandescent - Auto WB
Red 10.7%, Blue -14.1%

Flash Performance

The A520's built-in flash has a quoted working range of 0.45m - 3.4m (1.5 - 11.5 ft) at the wide end of the zoom and 0.45m - 2.2m (1.5 - 7.2 ft) at the tele end. It also works down to about 30cm (11.8 inches) in macro mode (in all cases assuming the ISO is set to auto). In our real-world tests the flash did a perfectly good job within its effective range, exposing perfectly in a wide range of situations and with virtually no color cast. My only complaint about the flash is that there is a noticeable delay between pressing the shutter and the picture being taken, due in part to the preflash burst used to calculate exposure. This can mean some of your social shots lack spontaneity, as you have to ask your subject to 'hold still for a minute'. Add to this the 7 seconds or so between shots when using flash and you've not got the best social camera in the world.

Skin tone
Excellent color, good exposure
Color chart
Virtually no color cast, good exposure

Macro Focus

As is common to most compact digital cameras the A520's macro mode is most effective at the wide end of the zoom, where you can get as close as 5cm. At the long end of the zoom the performance is less impressive - 25cm subject distance - but still pretty useful. There is inevitably some distortion when shooting very close up at the wide end, but it is not too strong, and certainly less so than many of its competitors.

Wide macro - 55 x 41 mm coverage
41 px/mm (1046 px/in)
Distortion: Average
Corner softness: Average
Equiv. focal length: 35 mm
Tele macro - 84 x 63 mm coverage
24 px/mm (613 px/in)
Distortion: Very low
Corner softness: Mild
Equiv. focal length: 140 mm

Barrel and Pincushion Distortion

Barrel distortion is - at 1.2% - fairly low for a camera in this class, and certainly doesn't mar real world scenic shots. Surprisingly, there is a tiny (0.1%) amount of measurable barrel distortion at the telephoto end of the zoom too.

Barrel distortion - 1.2% at Wide angle
Equiv. focal length: 35 mm
Barrel distortion - 0.1% at Telephoto
Equiv. focal length: 140 mm

Specific Image Quality Issues

It's hard not to be impressed with the results from the A520, which for the most part are sharp, well exposed and show excellent, natural color. They do benefit from a little post-processing (what camera's pictures don't?) - specifically some Unsharp Masking, but for output at up to about 8x10 inches you can quite happily get away with printing them as they come out of the camera.

Color is typical for a Canon consumer compact; bright and vivid, more saturated than could be considered totally natural, but very attractive and ideal for the typical user. We found very few exposure or focus problems and - as noted below - there is very little evidence of color fringing in everyday shots. In fact it's actually very hard to get a really bad shot from the A520, and though we're not talking about ground-breaking image quality here, for the target market - or for anyone wanting fuss-free reliability - that's more important than anything.

Color fringing

We found very little evidence of purple fringing in any of our real-world shots - where there is some it is only in overexposed areas, and is so soft as to be unnoticeable at normal print sizes. This is a real improvement over previous A series cameras (and many of the SD/IXUS models too).

100% crop 35 mm equiv., F4