While we faulted the SD300 for its average image quality, we were impressed by the performance, unrelenting burst capabilities, and great battery life that are equally evident in this upgrade. If you're looking for an ultracompact snapshot camera and don't need manual controls, lots of scene modes, or a powerful electronic flash, the marginally better image quality of this unit may lure you into the Canon fold. The Canon PowerShot SD400 looks good and feels good in your hands. At a lightweight 5.5 ounces and with dimensions of 3.4 by 2.1 by 0.83 inches, it won't create an unsightly saggy pocket. Although large hands may have trouble curling around this tiny package, a two-handed grip is your best bet for getting a steady shot, since your index finger operates both the shutter-release button mounted on the top surface and the concentric zoom lever.
Canon manages to pack a lot of components into a limited amount of space. For example, the front surface hosts the 3X zoom lens--which retracts flush behind a protective cover when powered down--a tiny microphone, a focus-assist lamp, an electronic flash, and an optical viewfinder window. The bottom edge includes an honest-to-gosh metal (not plastic) tripod socket and a cover for the battery and the SD/MMC memory card. One side edge has a flip-up access door for the I/O connectors.
Other than a recessed power button and a green LED power light on top, all the key controls are bunched on the right side of the back panel, next to the 2-inch LCD. The most common settings can be adjusted with the four-way cursor pad. You press up to switch between spot, center-weighted, and evaluative metering; down to cycle between single-shot, burst, and 2-second to 10-second self-timer modes; left to select normal, landscape, or macro focus; right to activate automatic, forced-on, red-eye, slow-sync, forced-off, and speedlight flash modes.
There's no mode dial on the SD400. Jumping from picture review to movie to photo mode is accomplished with a three-way sliding switch, while scene options are invoked from a menu that pops up when you press the Set/Function button in the center of the four-way cursor pad. The function menu also provides access to important controls such as exposure compensation (plus or minus 2EV in 1/3EV steps), ISO (50 to 400), compression ratio, and resolution.
A separate menu key pops up three pages of choices for shooting, setup, and customization. There's also a display button to cycle through the LCD status and preview options. A small button marked with a dot activates printing and sharing features. The Canon PowerShot SD400's feature set is, like its SD300 counterpart's, a quirky mix of minimalist-basic features with a few interesting add-ons. For example, only six scene modes are available, but one of them is an underwater option that's useful with an optional Canon waterproof housing. The remaining five range from the mundane (Portrait, Night Snapshot, Kids & Pets, and Indoor) to the unusual: a Digital Macro option that uses the zoom lever to expand a user-selectable portion of the image to fill the frame. There's also a clever My Colors mode that lets you increase the saturation of red, green, or blue hues; darken or lighten skin tones; swap colors; desaturate all colors but one; and adjust color balance. Unfortunately, there's no sports/action mode, nor is there any manual control over shutter speed or f-stop, which would have taken advantage of this camera's great burst capabilities.
The 3X zoom offers a good compromise between wide-angle view and telephoto reach, with a 35mm-to-105mm (35mm-camera equivalent) range, but the limited number of zoom steps made choosing the right focal length a jerky hit-or-miss proposition. The good news is that the nine-point or center-spot autofocus system works well down to 1.2 inches, although you'll need to use the LCD for framing because the tiny optical viewfinder is woefully uncorrected for parallax.
You can choose evaluative, center-weighted, or spot metering, and the camera will automatically select shutter speeds from 15 seconds to 1/1,500 second and f-stops from f/2.8 to f/4.9. Automatic noise reduction kicks in for exposures longer than 1.3 seconds. As is common with ultracompact cameras housing a tiny battery, Canon conserves juice by underpowering the flash unit, limiting it to 11.5 feet in wide-angle mode and just 6.6 feet at the telephoto setting when ISO is set to Auto.
Another quirky feature is this Elph's high-speed 60-frame-per-second mode, which can shoot half-speed slow motion at 320x240 resolution for as long as 60 seconds. Opt for near-TV-quality 640x480 clips with monaural sound at 30fps, and you can shoot until your memory card fills. Like the SD300, the PowerShot SD400 uses Canon's Digic II DSP to boost performance to impressive levels. Shutter lag was quick at 0.5 second under high-contrast lighting and respectable at 1.1 seconds under low-contrast lighting with the focus-assist switched on. A time-to-first-picture clocking of just 2.2 seconds means you won't wait long to snap off that impulse shot, and you'll be able to keep shooting every 1.62 seconds thereafter (3.01 seconds with flash).
Burst mode was a joy to use. You can shoot full-resolution photos until your trigger finger tires; we filled up our memory card with 143 shots in 110 seconds at a 1.3fps clip. When we dropped down to 640x480 resolution, the SD400 plugged away at 1.7fps for 3 full minutes before we halted the test.
Battery life from the 760mAh lithium-ion cell was also excellent, scoring 782 shots from a single charge, half of them with flash, intermixed with plenty of zooming, picture review, and card formatting to eat up juice. About 50 shots before the power pooped out, a red indicator flashed a warning, but nothing signaled waning battery life before that.
The LCD viewfinder worked better under dim lighting conditions than it did in bright sunlight, as direct illumination tended to wash out the display. Even though there was ghosting when the camera or subject moved, the LCD was still a better choice for framing than the inaccurate optical viewfinder, which showed only 82 percent of the subject area. This camera's image quality was marginally better than that of its 4-megapixel sibling, although both were a little disappointing. The Canon PowerShot SD400 produced photos that were sharper than the SD300's, but other 5-megapixel cameras in this class have done better, particularly at the telephoto zoom position. On the plus side, there was a good range of detail in shadows and highlights, although it was often masked by JPEG artifacts. Color saturation was somewhat muted at the default setting, and flesh tones showed a tendency toward yellow casts.
Chromatic aberration cropped up as purple fringing around backlit subject matter, and noise, not much of a problem at ISO 50 or ISO 100, was quite evident at the ISO 400 high end of the sensitivity range. While the flash provided even illumination beyond its nominal range, thanks to an automatic ISO boost the resulting photos suffered from excessive noise. In addition, the red-eye-reduction feature didn't seem to have much of an effect.