White Balance

The SD300 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. We've spoken to Canon about their approach to white balance and have been told that the warm colors we see when shooting under incandescant light are intentional and are intended to 'try to keep some of the warm atmosphere of this kind of shot'.

Outdoor - Auto WB
Red -0.3%, Blue 0.7%

Fluorescent - Auto WB
Red -0.5%, Blue 0.1%
Incandescent - Auto WB
Red 7.9%, Blue -11.8%

Flash Performance

The SD300's built-in flash has a quoted working range of 0.5m - 3.5m (1.6 - 11.5 ft) at the wide end of the zoom and 0.5m - 2.0m (1.6 - 6.6 ft) at the tele end. It also works down to about 30cm (12 inches) in macro mode (in all cases assuming the ISO is set to auto). In our real-world tests the flash did a fantastic job, exposing perfectly in a wide range of situations and with virtually no color cast. It's also very fast - even with the red-eye reduction turned on, meaning you won't miss any spur of the moment shots waiting for the flash. In fact - as long as you remember the range limitations of the flash you'll find this the perfect 'social' snapshot camera. We found the AF illuminator would allow focus in complete darkness (or as near as we can get) at distances of up to around 1.0m. In low light the AF illuminator can help focus at distances of up to around 1.8m.

Skin tone
Excellent color and exposure
Color chart
Excellent color and exposure

Macro Focus

As is common to most compact digital cameras the SD300's macro mode is most effective at the wide end of the zoom, where you can get as close as 3cm - unusually close for an 'ultra-compact'. At the long end of the zoom the performance is less impressive - 30cm 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 41mm coverage
41 px/mm (1041 px/in)
Distortion: Average
Corner softness: Low to average
Equiv. focal length: 35 mm
Mid Zoom macro - 90 x 67 mm coverage
25 px/mm (638 px/in)
Distortion: Low
Corner softness: Low to average
Equiv. focal length: 105 mm

Barrel and Pincushion Distortion

Barrel distortion is - at 0.8% - very low for a camera in this class, and certainly doesn't mar real world scenic shots. There is no measurable distortion at the telephoto end of the zoom. We did notice a tiny amount of vignetting (darkening of the corners of the frame) at the widest zoom setting, but didn't see this in real world shots.

Barrel distortion - 0.8% at Wide angle
Equiv. focal length: 35 mm
Pincushion distortion - 0.0% at Telephoto
Equiv. focal length: 105 mm

Noise Comparison

Here for visual comparison are four identical shots taken at 50, 100, 200 and 400 ISO settings in our studio. The exposures are not long enough for Canon's noise reduction to kick in (according to the documentation this happens with shutter speeds of 1.3 seconds and over). ISO 50 is very clean, and ISO 100 and 200 are perfectly usable. ISO 400 has plenty of visible noise, though it is no worse than the majority of the competition.

ISO 50 100% crop
1/3 sec, F4.5

ISO 100 100% crop
1/6 sec, F4.5

ISO 200 100% crop
1/13 sec, F4.5
ISO 400 100% crop
1/25 sec, F4.5

Specific Image Quality Issues

Of course all ultra-compact cameras such as this are going to present some kind of compromise when it comes to image quality. The question is how much of a compromise are we prepared to accept in image quality terms to get a camera that is truly pocket-sized?

First the good news; this is a Canon and has all the usual Canon trademarks; excellent, vivid but natural color, very accurate exposure and focus and a surprising amount of detail (see resolution tests). I think it would be fair to say that I expected to see considerably lower image quality than I got out of the SD300, and I doubt many of the target audience will find much to complain about here.

Of course it's not all a bed of roses, and there are a few significant issues that you need to be aware of when making your buying decision. By far the most common problem is edge softness, especially at the wide end of the zoom and at maximum aperture. We also found the usual Canon Achilles heel, purple fringing, to be a significant problem in most high contrast shots. Finally, in certain situations (wide end of the zoom, deep blue sky) there is some vignetting (darkening of the corners), though it is not a significant issue in most shots. Though we'd prefer not to see such problems, it is important to stress that these problems are unlikely to be a major cause of concern for the majority of users, and they will not mar 'normal'-sized prints significantly. This is, after all, a pocket snapshot camera.

Edge softness

Only really a problem at the wide end of the zoom and at maximum aperture, this is something we've come to expect from the very small lenses on ultra-compact zoom cameras, but it seems particularly bad on the SD300 - especially when shooting close-ups. The slight edge and corner softness is visible in most such shots viewed at 100% on-screen, though it is rarely a problem in prints. Take a look at the sample shots before deciding if this is a compromise you're happy to accept in order to get such a small, slim camera. Note that we didn't see significant edge softness at longer focal lengths.

100% crop 35 mm equiv., F2.8

Color fringing

Noticeable purple fringing is present to some degree in all shots containing very bright (especially overexposed) areas, and in many shots it's very pronounced. It's not enough to mar shots in most circumstances, but wideangle shots on bright days can produce very strong fringes at the boundaries where bright and dark areas meet. It is considerably worse at the edge of the frame, and - compact point and shoot camera or not - something Canon should be doing more to minimize.

100% crop 35 mm equiv., F2.8

Burnt out highlights/dynamic range

As with all small sensor compacts the SD300 has some problems with high contrast scenes with a very wide dynamic range. It's no worse than its competitors (this is a sensor issue more than anything else), but to Canon's credit the exposure system seems to do an excellent job of retaining highlight detail most of the time, and the default contrast is not as high as on some competitor models, meaning more fine tonal detail is preserved. Be aware, though, that there are times when the difference between the darkest and lightest parts of a scene will mean that something - usually highlight detail - is going to be lost.

100% crop 35 mm equiv., F2.8


A less common problem, but one we encountered on several occasions, is lens flare. This shot perfectly illustrates the phenomena - and why you need to be careful shooting in the general direction of the sun in the winter, when it sits low in the sky and casts long shadows.

100% crop 35 mm equiv., F5.6