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Photographic tests

White balance

The A720 IS has six white balance presets (daylight, cloudy, tungsten, aquarium and two fluorescent settings) in addition to the default auto white balance. There is also a 'manual' white balance setting that allows you to point the camera at a neutral target to set the white balance. This manual 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 incandescent (tungsten) lighting causes a fairly strong orange color cast (and the appropriate preset only gives reasonable results). If you don't like the warm tone, you need to switch to manual WB.

Auto White Balance Fluo Preset Auto White Balance Incandescent preset
Fluorescent light - Auto white balance average,
Preset white balance average
Incandescent light - Auto white balance poor,
Preset white balance average

Flash

The A720 IS's built-in flash has a quoted working range of 0.3m - 3.5m (1.0 - 11ft) at the wide end of the zoom and 0.5m - 2.5m (1.0 - 8.2 ft) at the tele end, which is a bit on the underpowered side. And these figures are for Auto ISO mode, so the range will be reduced still further if you limit ISO down to its better settings.

The flash does also have a slow-sync function that uses a longer shutter speed to let in more background light. This can be set to fire the flash at the beginning or end of the exposure - an impressive level of control for such a camera. Our only complaint - common to all cameras powered by two AA batteries - is that recycle time (when shooting at anything other than the wide end of the lens / short distances) can get very long - up to 8 seconds if the batteries aren't in tip-top condition.

Skin tone -
Good color and exposure
Test chart
Slight warm tone, slight underexposure.

Macro

The A720 IS's macro mode is most effective at the wide end of the zoom, where you can get as close as 1cm, capturing an area 20mm across - which is really pretty impressive though the lens may block the light out if you try to actually use it quite so close up. At the long end of the zoom the performance isn't bad either - with a 55cm subject distance capturing an area 10cm wide. There is noticeable distortion, chromatic aberration and softness at the corners when working at the closest distance but this is neither unusual nor unbearable.

Movie mode

As well as the 640x480, 30fps mode that has become standard on Canon's compacts, the A720 IS also features a 'long-play' mode that maintains the frame size and rate but reduces quality (increases compression) to keep the file size down. 'Compact' mode limits resolution to 160x120pixels and 15fps to keep files to an email friendly size.

Overall quality is very good, with movies very smooth and showing few compression artifacts. The AVI files are large - at the best quality setting (640x480 / 30fps) you're burning around 1.5MB every second.

The optical zoom locks in position once you're pressed the record button, but you can continue to use digital zoom throughout.

Sample movie: 640 x 480 pixels @ 30 fps
File size: 9.6 MB, 5 secs

Click on the thumbnail to view the movie (caution: large file!)

Resolution

Thanks to the extra million pixels the A 720 IS is pulling a touch more resolution out of our chart, and overall the results are a noticeable improvement. There's a little moiré at the highest frequencies, but overall these are better than we'd expect from a camera in this class, showing that the constant sensor upgrades we complain about all the time do bring some benefits. If you look at the test chart full size you'll also be able to see a little corner softness and mild CA, but outside the test studio at standard viewing sizes these simply aren't visible.

Crops

Click here for the full resolution test chart

Horizontal LPH

Absolute resolution 1750 LPH
Extinction resolution 2150 LPH *

*moiré visible

Vertical LPH

Absolute resolution 1700 LPH
Extinction resolution 2150 LPH *

*moiré visible

Distortion and other image quality issues

Despite the wideangle lens the A720 IS exhibits average distortion at the wide end of the zoom -0.9% barrel distortion (click here for test chart) - not at all bad for a 6X zoom, but you won't want to be using it to copy artwork. Better still, there still less (0.3%) distortion at all at telephoto end (click here for test chart).

General comments

On the whole, the A720 IS produces decent results in a wide range of situations, and - perhaps more important - it does so reliably, shot after shot. If you really provoke it, with extremes of light and shade, it will mess it up but that's because of the limited dynamic range that small sensors have (you can get even the most expensive digital cameras to do it if you really try). And there's a proper manual mode if you're determined to get at least one element of the picture exposed in truly impossible conditions.

Highlight clipping / contrast issues

And here are the results of trying to expose a shot with extremes of light and shade - The camera can either expose the sky correctly and leave the rest of the photo nearly black, or it can try to expose most of the photo correctly and let the sky clip to white. It's not particularly pretty and has also caused pretty extensive fringing at the edge of the bright areas. But we'd struggle to think of a camera that could do much better in the situation. There's also some pretty strong purple fringing here, but this is restricted to this kind of shot.

100% crop 35mm equiv., F2.8
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