Solid image quality, usable ISO 800 performance and a full set of manual controls make the Canon PowerShot A540 an excellent choice for photo enthusiasts looking for an almost-pocketable second camera, or for budding photographers who aren't ready to move up to a superzoom EVF model or digital SLR. Only a flash that's slow to recycle lessens the appeal of this camera's 4x zoom lens, 6-megapixel resolution and otherwise excellent performance. There are even more than a dozen scene modes for those times when you're tempted to switch on the autopilot.
The A540 is a more full-featured, less compact alternative to the spritely Canon Digital IXUS 60, though its position in the A series between the very similar 5-megapixel A530 and the 6-megapixel A700 seems to exist solely to fill the price gap between the two.
At 89 by 64 by 43mm and 221g when loaded with an SD memory card and a pair of AA batteries, this camera feels relatively lightweight and fits comfortably in your hand. You zoom via a jog dial that's concentric with the shutter button. Rotating the dial is easier when shooting with two hands, but one-handed shooting is entirely practical. The coarse, 85,000-pixel, 64mm (2.5-inch) LCD tends to wash completely out in direct sunlight, but you can always use the bright optical viewfinder instead.
Canon's usual A-series mode dial sits atop the camera and, like the conveniently arranged array of buttons on the camera back, can be operated with your right thumb. Together, these controls make the A540 responsive and easy to navigate. For example, you can spin the mode dial to switch between auto, programmed, manual, aperture priority or shutter priority, plus scene modes including Portrait, Landscape, Night Scene, Stitch Assist and Movie. Another ten scene modes are available at the SCN notch on the dial. Beginners and less experienced shooters will probably opt for program autoexposure, switch to full auto or choose one of the scene modes.
Metering options include evaluative, centre-weighted or spot. When in a shooting mode other than auto, manual or movie, the trash/EV button adjusts exposure to plus or minus 2EV in 1/3EV increments. It's accompanied by a print-sharing button and a 'Disp' key that varies the amount of information displayed on the LCD. Up and down keys toggle flash and macro focus modes respectively. Other setup and shooting functions are logically divided among menus accessed through the menu and function/set buttons.
Intermediate and advanced shooters will love Canon's user-friendly exposure controls. Left and right cursor keys let you make shutter- and aperture-priority adjustments. In full manual mode, the EV button toggles between shutter speed (15 seconds to 1/2,000 second) and f-stop (f/2.6 to f/8) control. The 35mm-to-140mm (35mm-camera equivalent) zoom lens focuses to as close as 50mm using lamp-assisted and one- or nine-point autofocus or manual focus. Finally, you can shoot movies at a maximum of 640x480 pixels at 30fps.
In line with the A540's enthusiast fan base, this camera supports add-on lenses that affix to a bayonet mount under the plastic collar around the lens. Current options include 1.75x telephoto and 0.75x wide-angle lenses, as well as any 52mm filter adaptor. For those who live the life aquatic, there's also an underwater case. Though this camera lacks a hotshoe, you can attach a higher-powered HF-DC1 accessory flash. It fits on a bracket that screws into the tripod socket and fires as a slave in cordless mode.
There are a number of cool features, such as Color Swap mode, which lets you photograph, say, purple roses by exchanging all the reds in a scene with an alternate colour, as well as a 4.4-megapixel widescreen framing mode. The ISO 800 sensitivity setting also comes in handy and isn't quite as noisy as those we've seen on some compact cameras.
Low shutter lag and robust continuous shooting are the biggest strengths of the Canon A540. Under high-contrast lighting conditions, this camera's autofocus system lets it snap off a picture in 0.7 seconds and lags about 1.1 seconds under more challenging low-contrast light, even with the crimson focus-assist lamp. The camera responds quickly to fast-moving shooting situations, powering up for an initial shot in 1.9 seconds, with shot-to-shot times of just 2 seconds thereafter.