The PowerShot A540 is a 6-megapixel camera with a quick Digic II image processor, a new, more sensitive CCD sensor, a large 2.5-inch screen and 4x optical zoom.
It's pretty much the same size as the outgoing PowerShot A520 and takes the same two AA-sized batteries. These don't last a very long time, so you'll certainly want to invest in a few sets of rechargeables. Canon does quote a higher batter life than the older PowerShot A520, but everything is relative.
Perhaps contributing to the poor battery life, the 2.5-inch screen brings the PowerShot 'A' range up to date. The PowerShot A540 actually has a lower resolution screen than the outgoing A520, and the extra size makes it very easy to see the individual pixels on the screen. Having said this, the 2.5-inch screen is more easily viewed at a greater distance than a smaller screen, and in our opinion is worth having.
Buttons on the camera follow the usual layout for Canon PowerShot models, and we found the menus quite easy to navigate. Advanced options are there without being obstructive to the customer who wants to just point and shoot, but there are also plenty of options to please those who want to experiment.
A large dial on the top of the camera switches between recording modes, with fully automatic mode complemented by program, aperture priority, shutter speed priority, full manual mode, and a set of preset modes for portrait, landscape, night, and then a mode called 'SCN', which offers further presets for underwater and so on. For underwater photography, a plastic enclosure is available as an option.
The last mode is for video. This camera, like many these days, can function quite well as a video device. For some, it could replace the home video camera. The resolution can be set to 320 x 240 pixels, 640 x 480 or a compact mode for e-mail, and it can handle 30 frames per second or 60 frames per second for fast action, although the latter can only be used in 320 x 240 pixel mode. Video is saved as an MPG file, and the supplied driver CD includes the codec, which is known as 'Motion JPEG'.
Another function we found to be useful is the continuous shoot mode. If not using the flash, the camera sports a capture rate of about 2.3 frames per second, continuously taking pictures until the card fills up. This is a great way to ensure that a good shot is captured and avoid later disappointment when reviewing the pictures.
A switch on the back of the camera toggles between capture and playback modes. Pictures and video are all listed together, with video footage simply marked with a camera icon. Holding down navigation buttons can increase the speed of playback, and using the zoom button and other buttons modifies the behaviour of the playback in too many different ways to describe here.
Picture quality is good using default modes. However, care is needed with the new 800 ISO mode, as it seems to cause photos of even well-lit subjects to appear very grainy. Using fully automatic mode or a low ISO number, images were clear and focusing was quick and accurate, although focusing takes longer in lower light conditions. There was also little evidence of purple fringing between very bright and very dark areas, which was good to see (or rather, to not see).
There is a built-in flash for low light conditions, which does a reasonable job, although it's neither very powerful nor very quick to recharge. Canon does offer an optional add-on flash unit for this camera, which attaches to the side.
It's easy to fill a memory card, with both continuous shoot mode and video functionality. We found that we needed to empty the 512MB card we were using quite frequently (Canon only supplies a useless 16MB card with the camera). The card is located in the battery compartment, which makes removal a bit of a pain and requires the camera to be powered off. It would be better if the card were located on the side of the camera, as with other PowerShot models.
The supplied software is minimal, but you'll probably need to install it anyway, if only to get the Motion JPEG video codec that the camera uses to encode video files. As you might expect from a printer manufacturer, the software is partly geared towards home printing, although there is also a passable photo organisation package called ZoomBrowser EX.
