White Balance

Being based around the same DiGiC processor as the S45, G3 and S400 the SD100 produced very similar results. The only noteworthy item was improved automatic white balance under fluorescent light. An orange cast for automatic white balance under incandescent light, preset white balances worked well in almost any light, manual white balance near perfect no matter what the light.

Outdoors, Auto	Outdoors, Cloudy (or Sunny)	Outdoors, Manual
Incandescent, Auto	Incandescent, Incandescent	Incandescent, Manual
Fluorescent, Auto	Fluorescent, Fluorescent (or H)	Fluorescent, Manual

Macro Focus

We didn't expect much on the macro front from the SD100's tiny two times zoom lens, and we weren't surprised either. The closest horizontal frame coverage of 67 mm (2.6 in) was achieved at wide angle.

Flash Performance

The SD100's small flash unit has a specified range (at Auto ISO) of 3.0 m (9.8 ft) at wide angle and 2.0 m (6.6 ft) at telephoto zoom. Exposure was on the whole very good, the camera metered the scene well and exposed accurately, there was no color cast and flash images had good color and tonal balance. The SD100 has no flash power compensation setting.

Skin tone - Natural color, no blue cast, good exposure	Color patches - Good color balance, no color cast, good exposure

Night exposures

Just like other recent PowerShot digital cameras the SD100 has an automatic noise reduction mode which is enabled for exposures of 1.3 seconds or slower. To achieve such long exposures you must first enable the camera's "long exposure" feature. Select a long exposure from the FUNC menu, press 'SET' with the exposure compensation setting visible and it will switch to long exposure. The SD100 supports long exposures of 1 to 15 seconds. Noise reduction works by taking a 'dark frame' after the main exposure and using any noise from that frame to remove noise in the main shot. Night exposure performance was good with no hot pixels or 'black pits' (noise reduction errors).

Long exposure: ISO 50, 4 sec, F2.8

Barrel and Pincushion Distortion

The SD100's two times optical zoom lens provides a range of 35 to 70 mm (equiv.). At wide angle the lens exhibits just 0.6% barrel distortion (which is very good for an ultra-compact lens), at telephoto we could measure no pincushion distortion. Overall a very good performance for this test.

Barrel Distortion, 0.6% @ wide angle	Pincushion Distortion, none @ telephoto

Vignetting / Light fall off

Our vignetting / light fall off test is very simple, a shot of a blank wall from two meters away, vignetting will always be most visible at wide angle and maximum aperture and will start to disappear at smaller apertures and/or further zoom. The SD100 showed very little corner vignetting at wide angle, nothing that would be visible in normal 'every day' shots.

Very little corner vignetting visible at wide angle and maximum aperture (F2.8)	No noticeable vignetting at telephoto

Purple Fringing (Chromatic Aberrations)

Nothing is without its price, the SD100's ultra-compact lens system did indeed exhibit some chromatic aberrations (purple fringing), this was most noticeable around high contrast detail against the sky as a background. Lens softness also contributed to this.

Some fringing visible in this 'every day' shot	Our standard chromatic aberration test shot

Overall Image Quality / Specific Issues

Based on the same image processing engine as the S45, G3 and S400 the SD100 delivers good, low noise images with good color balance, good tonal balance and as much detail as we could expect from an ultra-compact three megapixel digital camera. I did feel that the SD100's lens was not as sharp as some of the competition, nor as sharp as some of its bigger brothers. Canon's conservative approach to image sharpening added to lens sharpness could lead to images looking softer than we would like.

Red Overexposure Color Shift

Not something we would expect to see on a modern Canon digital camera but we did indeed notice some red overexposure color shift in a similar shot to that which affected the Casio EX-Z3. The guards red jacket in direct sunlight has been pushed into overexposure (red channel is 255) and the levels of the other channels causes the color to shift to orange. You can see the true color of the jacket bridge to the right of the image.