The PowerShot A-series is possibly the longest-running digital camera range still in production, having started with the 1.3-megapixel PowerShot A10 back in early 2001. While the basic shape has remained relatively unchanged since then, with a functional rectangular body and a handgrip holding AA batteries, the details have evolved over time and the result is a camera whose form fits its function almost perfectly. The body is made of plastic, but its rounded corners give it an inherent strength and while there are a few squeaks if you give it a squeeze the overall build quality is excellent. The A590 is finished in a high-gloss gunmetal colour, and this does make it a bit slippery, but the shape of the handgrip and the position of the controls make it very secure to hold. However I can't help but think that a textured non-slip finish to the handgrip would be an improvement to the handling, especially for users with limited grip or manual dexterity.
It's hard to find fault with the accessibility of the controls. Although it is by no means a bulky camera, measuring 94.3 x 64.7 x 40.8mm and weighing around 225g including a pair of AA batteries, it still has room on the back for a large, easy-to-use D-pad, four other buttons and a nice solid slider switch for record/playback selection, while leaving plenty of space for your thumb. The main mode dial on the top plate is a bit crowded with 13 settings, but it turns with a nice positive click and is recessed so it's unlikely to be jogged accidentally. The zoom control, as usual on a Canon camera, is a rotary bezel around the shutter button, and it is easy to operate, although the zoom travel is a bit jerky and is stepped with only seven increments between minimum and maximum.
The manual exposure controls are a lot better than on some semi-manual compacts. Aperture settings from f/2.6 to f/8.0 and shutter speeds from 15 seconds to 1/2000th of a second can be selected in 1/3 EV increments, giving the A590 the potential for real creative photography. The optical viewfinder is also better than most; it is surprisingly large and bright, and since it is positioned almost directly over the lens it minimises parallax problems at close range. Its frame coverage is approximate 75-80%, which is about average for a compact camera.
I'm less impressed by the monitor screen, which seems to have been one of the few corners that have been cut to keep the price low. With 115k dots it isn't particularly sharp, and its angle of view is also rather restricted, I would estimate to around 45 degrees either side of perpendicular. This means it is almost impossible to see if you are trying to shoot with the camera held above head height.