White Balance

The S2 IS features a grand total of seven white balance settings including the default automatic mode. There's also a manual (custom) white balance option, which is created by aiming the camera at a white (or gray) subject and pressing the SET button. Automatic white balance appeared to work well outdoors and in fluorescent lighting, but as per previous Canon digital cameras less well in incandescent light, where it produced a strong orange color cast (though not as bad as some models!). It is advisable to switch to the tungsten preset (or set a custom WB) when shooting indoors if you don't like a warm cast to your indoor shots.

Outdoor - Auto WB
Red -0.8%, Blue -1.9%
Fluorescent - Auto WB
Red -0.3%, Blue -1.2%
Incandescent - Auto WB
Red 1.8%, Blue -4.9%

Flash Performance

The built-in pop-up flash unit has a specified range of 5.2 m at wide angle and 4.0 m at telephoto (when the ISO is set to auto) - in both cases this is around 1.0 m (39 inches) greater than the S1 IS. In use we found it to meter very well indeed, with most indoor flash shots perfectly exposed unless the subject was closer than around 0.7 m, at which point some burning out of highlights occurred. The FUNC menu offers a Flash Exposure Compensation setting (-2.0 to +2.0), and the AF illuminator (missing from the S1, now thankfully included) helps focus in low light (though it isn't powerful enough for such a long zoom camera - it only really works over distances of about 1.3 m and lower).

Skin tone - Slight warm tone, excellent exposure Color chart -Slight warm tone, excellent exposure

Macro Focus

One of our complaints about the S1 IS was the rather mediocre macro performance, so we were very interested to see the new 'super macro mode' in the S2 specification. First let's look at the standard macro mode, which allows you to get down as close as 10cm (at the wide end of the zoom). It's okay, but nothing special (fitting an area of around 11cm across into the frame) and is actually worse than the S1 IS. At the telephoto end of the zoom you can actually get slightly higher magnification (photographing an area of around 8.5cm across), with less distortion and less corner softness, albeit from a much greater distance (about 70cm).

Wide macro - 108 x 81 mm coverage
24 px/mm (608 px/in)
Distortion: Average
Corner softness: Average
Equiv. focal length: 36 mm
Telephoto macro - 85 x 63 mm coverage
30 px/mm (773 px/in)
Distortion: Low
Corner softness: Low
Equiv. focal length: 432 mm

Super Macro mode

If its normal macro mode is nothing to write home about, the S2 IS has a rather unique trick up its sleeve - a 'super macro mode' that allows you to focus down to an unprecedented 0cm from the front element. Yes, that's right, this is the first compact we've ever seen that can actually focus on dirt on the front of the lens! Of course there aren't many things you can actually photograph from 0cm - they either need to be lit from behind (you can use the S2 IS to shoot 35mm slides (example) if you don't mind the cropping, distortion and corner softness!) or small enough that they don't fill the frame. In most cases the shadow of the lens obscures your subject so much that you can't use it at distances of less than a few centimetres, at which point the subect area you're photographing is around 40mm across - roughly the same as most of its competitors (such as the Panasonic FZ5), but with the ever-present danger that you'll move so close that you end up causing permanent damage to the front element of the lens. Still, it's fun to play with and does allow you to take some unique photographs.

Super macro - 20 x 15 mm coverage
124 px/mm (3142 px/in)
Distortion: High
Corner softness: Average
Equiv. focal length: 36 mm

Focus distance for this shot was 0cm (chart lit from behind).

Banknote detail, backlit. Flower, with stamen touching front element

Noise Comparison

Here for visual comparison are three identical shots taken at 50, 100, 200 and 400 ISO settings in our studio. Although the ISO 50 and 100 results are pretty clean (they have relatively low luminance noise), the effects of noise reduction at ISO 200 are fairly obvious, and at ISO 400 there is a distinctly 'blotchy' appearance to the mid-tones and shadows. Usable, and no worse than most of its competitors, as with all cameras in this class, we'd recommend using the S2 IS ISO 400 setting only when you really have to.

ISO 50 100% crop ISO 100 100% crop
ISO 200 100% crop ISO 400 100% crop

Barrel and Pincushion Distortion

The S2 IS exhibits remarkably low distortion given the huge focal length range - 1.0% barrel distortion at the wide end (better than the S1 despite the wider angle), and only the tiniest amount of measurable distortion at all at the full 432mm telephoto end. There is also only barely measurable - and hardly noticeable - vignetting.

Barrel distortion - 1.0% at Wide angle
Equiv. focal length: 36 mm
Pincushion distortion - 0.1% at Telephoto
Equiv. focal length: 432 mm

Specific image quality issues

Generally image quality was good, though by no means perfect. The images are generally well exposed, well focused and pretty detailed. If viewed at 100% they have the same smoothness - and overall lack of biting sharpness - as the S1 IS results, though they are considerably better. We also found sharpness drops fairly dramatically at apertures of F6.3 and higher (due to diffraction effects), though this is by no means unique to this camera - it's just useful to know you get the sharpest results in the F4.5 to F5.6 range.

Aside from the fringing issue mentioned below our only complaints are a slight tendency to overexpose, the usual lack of dynamic range seen with all 5.0 MP cameras (which results in more blown highlights than we'd like to see) and a slightly 'over-processed' appearance, specifically over-sharpening. At least you can play with the contrast, sharpness and saturation - see the next page for more details.

Purple fringing

We found some fairly prominent chromatic abberation (red fringes on the top of edges, blue on the bottom) in the corners of most wideangle shots at F4 or below (first two examples), and some purple fringing at the boundaries of high contrast edges (3rd example below), though it's better than the S1 IS, and only seems to be a problem in scenes with very bright, blown highlights.

100% crop 36mm equiv., F4
100% crop 36mm equiv., F4
100% crop 36mm equiv., F4