The SX100 IS has five white balance presets (Daylight, Cloudy, Tungsten, Fluorescent, Fluorescent H) in addition to the default Auto and a custom (measured) mode. We did not experience any problems with Auto White Balance when shooting our outside galleries and the SX100 IS also copes well with most mixed light sources. However, it struggled to correct the color cast caused by shooting under artificial lighting.
While the performance under fluorescent light is about average, Auto White Balance really struggled with incandescent light sources, producing very warm results. According to Canon this is intentional in order to preserve the 'warm' atmosphere created by incandescent light bulbs. If you prefer your colors more neutral you should switch to the incandescent preset which produces much better results although far from perfect. In those instances when color temperature is crucial, manual White Balance is your best bet.
|Incandescent - Auto WB
Red 12.0%, Blue -21.3%
|Incandescent - Incandescent preset WB
Red 3.2%, Blue -6.4%,
|Fluorescent - Auto WB
Red 1.6%, Blue -14.7%,
|Fluorescent - Fluorescent preset WB
Red 2.4%, Blue -4.9%,
The built-in flash has a range (using auto ISO) of up to around 3.0 m (9.8 feet) at the wide end of the zoom, dropping to 2 m (6.6 feet) at the long end. We found color accuracy to be very reliable with the flash producing very slightly warm results. This is in most cases desirable as it produces natural skin tones in flash portraits. As expected from an AA battery powered camera, flash recycling times can be very long. When battery power is low you might as well go away and make a cup of tea for yourself and your subjects while waiting for the flash to recharge. Flash recycling times can get pretty close to the 10 sec mark, so always make sure you carry a fresh pair of AAs when you know you are going to use the flash a lot.
|Skin tone - Slightly warm tone,
||Color chart -good color accuracy,
Like a number of cameras in the superzoom league the SX100 IS features a macro mode that lets you focus down to a very close distance at wide angle: 1 cm in this case. The real-life applications of this feature are quite limited though. This close up you are quite likely to shade the subject with the camera itself, not to mention that any mobile subject would have made a getaway long before you get that close. Having said that the macro mode is fun to play with and you can get some interesting results.
At the wide end of the zoom (1 cm minimum focus distance) it captures an area 27mm (1.1 inches) across. At the long end of the lens the minimum distance is approximately 100cm, covering an area of 115mm (4.5 inches) across. There is quite some distortion at the wide end; that's hardly a surprise considering the lens is covering an extremely wide angle at this setting. Distortion at the tele end exists (and there's a touch of chromatic aberration), but is hardly noticeable. There is some corner softness although it won't be visible in anything but the largest of prints.
Barrel and Pincushion Distortion
The distortion measurements for the SX100 IS are not bad at all considering the long zoom range. Barrel distortion at the wide end is pretty average at around 1.0%. This will be visible on straight objects close to the edge of the frame but it is not any worse than the competition. At the long end there is only very minor pincushion distortion at 0.2%, nothing that would be of any relevance unless test charts are one of your favorite subjects..
|Barrel distortion - 1.0% at Wide angle
Equiv. focal length: 36 mm
|Pincushion distortion - 0.2% at Telephoto
Equiv. focal length: 360 mm
Specific image quality issues
The SX100 IS is a very close relative to Canon's trusted A-Series cameras and it does therefore not come as a surprise that the image output is very similar both in terms in quality and 'character'. The SX100 IS produces admirably refined results at lower ISO settings that match image quality of far more expensive cameras - as long as you don't expect miracles and don't spend too long looking at 100% crops. Colors are natural, and auto white balance in daylight generally works accurately (although sometimes slightly on the warm side). Exposure is spot on in almost any shooting situation and so is the focus unless you try to track a fast moving object. Canon's approach to in-camera sharpening is fairly subtle. If you prefer your images slightly sharper, that's your choice, and you can easily apply an unsharp mask in post-processing, at least you've got the option (which you don't have if out-of-cam images are over-sharpened already).
Almost as expected from a camera with a 1/2.5 in sensor there is some highlight clipping in very bright, high contrast conditions. This is 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). The reason for this is usually a combination of the limited dynamic range of the small sensors and a steep tone curve. The problem can be mitigated by applying some negative exposure compensation and/or reducing contrast in the My Colors menu.
Noise and NR at low ISO settings
Shooting in anything less than perfect light brings out some of the nastier characteristics of the tiny sensors used in compact cameras and the SX100 IS is no different. There are visible shadow noise and blurring of fine texture such as foliage (caused by noise reduction) even at base ISO. This is common to most small sensor cameras and by no means worse on the SX100 IS than on the competition's comparable cameras, but that doesn't make it any less unpleasant, and limits the usefulness of the output for large prints.
|100% crop||360mm equiv., F4.3, ISO 80|
Color fringing around highlights is certainly not unique to the SX100 IS but some other manufacturers (such as Panasonic) have managed to rid of it through in-camera processing. Unfortunately Canon has not adopted this approach yet. Having said that red fringing on the SX100 IS is only visible in the typical high contrast scenarios and well within acceptable limits, we have certainly seen much worse in the past. Just something to watch out for.
|100% crop||360mm equiv., F4.3|