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White Balance

The A570 IS has six white balance presets (Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent H, Underwater) in addition to the default Auto and a custom (measured) mode. In our tests the auto WB system worked pretty well in all outdoor situations and coped well with mixed light sources. However, it struggled to correct the color cast caused by shooting under artificial lighting. In fact as the results below show, Auto WB is pretty poor under incandescent light and only marginally better under fluorescent light. If you want neutral tones in such situations you need to use preset or manual white balance which deliver much better results.

Incandescent - Auto WB
Red 11.27%, Blue -17.48%
Poor
Incandescent - Incandescent preset WB
Red 1.82%, Blue -1.6%,
Good
Fluorescent - Auto WB
Red 2.26%, Blue -13.5%,
Average
Fluorescent - Fluorescent preset WB
Red 1.79%, Blue -4.78%,
Average

Flash Performance

The built-in has a range (using auto ISO) of up to around 3.5 m (11.5 feet) at the wide end of the zoom, dropping to 2.2 m (7.2 feet) at the long end. We found color accuracy to be very reliable with the flash portrait showing a very slight warm tone. This, in most cases, is better than being too cool, and produces nice skin tones. Our test portrait also showed minor signs of underexposure which probably is caused by the white background in our test setup. In 'everyday' flash shooting situations this underexposure wasn't observed. One minor complaint is the flash shot-to-shot time. If the batteries are low and/or your subject is a few feet away flash recycle times can rise to as much as 8 or 10 seconds. This however is a fairly common issue with AA battery powered cameras.

Skin tone - Warm tone, slight underexposure
Color chart -good color accuracy,
good exposure

Macro Focus

The A570 IS's macro mode is fairly unspectacular. It lets you get as close as 5cm at the wide end of the zoom, capturing an area 56mm (2.2 inches) across, which is hardly class-leading. At the long end of the lens the minimum distance is approximately 30cm, covering an area of 79mm (3.1 inches) across. There is some distortion at the wide end, at the tele end this is hardly noticeable. Corner softness is low.

Wide macro - 56 mm x 42 mm coverage
54 px/mm (1380 px/in)
Distortion: High
Corner softness: Low
Equiv. focal length: 35 mm
Telephoto macro - 79 mm x 59 mm coverage
39 px/mm (983 px/in)
Distortion: Low
Corner softness: Low
Equiv. focal length: 140 mm

Barrel and Pincushion Distortion

The distortion measurements for the A570 IS are fairly good. Barrel distortion at the wide end is about average at around 1.3%, which is high enough to be visible if shooting anything with straight edges, but no worse than most competitors. At the long end there is no measurable distortion at all.

Barrel distortion - 1.3% at Wide angle
Equiv. focal length: 35 mm
Pincushion distortion - 0.0% at Telephoto
Equiv. focal length: 140 mm

Specific image quality issues

Although the A570 IS is not a major leap forward there are no big complaints here, and it produces admirably refined output that belies its status as a 'budget' model. We've been consistently impressed with the output produced by the many and varied A series compacts, and the A570 IS keeps up the tradition.

Results are detailed and show excellent focus and exposure in a wide variety of shooting situations although the images sometimes might be a touch on the soft side when viewed at 100% on-screen. This however can easily be rectified with a little unsharp masking. We find it preferable to give this option to the user rather than providing over-processed images which can't be altered sensibly in imaging software. The A570 IS's colors are natural, and white balance generally fairly accurate (unless you're shooting under tungsten lighting). Noise is fairly well managed at up to ISO 400. Higher levels should be reserved for emergency use only but at all ISO levels detail is preserved comparatively well which is due to a well balanced approach to noise reduction.

There is some evidence of purple fringing and CA in our real-world but well within acceptable limits. It only occurs in extreme contrast and then at a level that will only be visible in very large size prints.

Highlight clipping and color blooming

As usual you can expect to see occasional highlight clipping in very bright, contrasty conditions - something common to virtually all high pixel count small sensor compacts. These cameras struggle to capture the full tonal range in scenes with a large dynamic range (high contrast, very bright days). Like previous A series models, the A570 IS's problem seems to be a combination of the usual limited dynamic range of such sensors and a fairly steep tone curve, which can lead to quite harshly clipped highlights.

You can fairly easily counteract this with a little negative AE compensation or reducing contrast in the My Colors menu. To be fair the problem isn't widespread and only crops up in a small number of exposure situations. Again this was a very rare occurrence and quite difficult to reproduce, so not a major issue for your everyday shooting.

In very high contrast scenes with very strong bright colors we also saw some channel clipping and a little bleeding of color (blooming) across very high contrast edges, but it's nothing that's likely to affect prints and was only observed in a couple of shots.

100% crop 118mm equiv., F5
100% crop 35mm equiv., F4
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