The Canon Powershot SD900 currently appears at the top of Canon's SD-series due to its 10 megapixels sensor. Even though this digital camera is relatively good, there are several better ultra-compact cameras in the same series. Looking only at capabilities, except in terms of resolution, the SD900 is the least capable of its siblings. There is the SD800 IS which has a stabilized wide-angle 3.8X optical zoom lens and the SD700 IS which has a stabilized 4X optical zoom lens. The SD900's lens starts at an unusually narrow 37mm which makes it less suitable for shooting in tight places or wide landscapes. Stabilization is particularly important since it allows shooting still subjects at lower ISO settings and therefore produce less noisy images. Note that the SD900 has a significant advantage in terms of movie resolution compared to most digital cameras currently available.

The performance of the Canon Powershot SD900 is above average for an ultra-zoom camera. It is particularly fast in operation and can shoots images continuously at 2 FPS. For a 10 megapixels camera, this is definitely an achievement. In terms of image quality, the SD900 produces sharp images at low ISO settings with pleasing color and relatively low image noise up to ISO 400. Like most cameras, the automatic white-balance has trouble with artificial light, but there is thankfully a custom white-balance mode which produces accurate colors. Due to its resolution, ISO 400 is even usable for medium prints, say 8"x10". Loss of details increases slowly but steadily from ISO 200, but will only be visible for large prints.

The SD900's main problems are due to certain aspects of its sensor. The sensor appears to have a very narrow dynamic range. The resulting problem is that the SD900 overexposes images more frequently than its peers. Exposure compensation can help but will cause shadows to be underexposed. Between these two options, most photographers would choose to underexpose the shadows rather than blowing highlights. Of course, it would be better to do neither. For this reason we prefer recommending other ultra-compact cameras. Note that we have seen this sensor before, in the Canon Powershot G7. With the G7 this was enough to keep it away from a good rating because of stiff competition from other compact digital cameras. With the SD900, an average rating would be too low because it outperforms average ultra-compact cameras in numerous areas: sharpness, noise-levels, speed and display quality.

The bottom line is that there are several cameras which we would recommend above this one, without saying that the SD900 is not a good camera. Still champion among ultra-compact cameras is the Fuji Finepix F30 with superior image quality, more than twice the battery-life and a more powerful flash. Not far behind is the Fuji Finepix F10, also with superior image quality, battery-life and flash. Finally there is the excellent and more versatile Canon Powershot SD800 IS. With its wide-angle lens, the SD800 covers a wider-range of subjects. With its stabilization, the SD800 IS can shoot at lower ISO settings (with lower shutter-speeds) than the SD900 in the same condition. Effectively, this means that under less-than-ideal lighting, the SD900 loses some of its resolution advantage compared to the SD800.