Like the 10D before it, the 20D has an AF-Assist facility that relies on the built-in flash to fire a quick burst of flashes to enable easier auto focusing in low light conditions. By default, the camera will also fire a full flash as well, which may not always be wanted. However one of the Custom Functions on the 20D (which isn’t available on the 10D) will disable the flash unit but still allow AF-Assist. Although using the flash is more accurate than the dedicated AF lamp used on the older D30 and D60 models, the flash bursts can be quite obtrusive if, for example, you’re trying to shoot in a darkly lit museum that doesn’t allow flash photography. Thankfully, the 20D’s AF-Assist shouldn’t be required that often, because the new AF system does focus extremely well even in very low light or when shooting low contrast subjects.
The 20D offers three different auto focus modes - One-Shot for still subjects, AI Servo for moving subjects, and also an AI Focus mode that switches automatically from One-Shot to AI Servo if the subject starts moving. Naturally, if the shooting conditions limit the effectiveness of auto focusing then switching the lens to manual focus is always an option.
In addition to the default auto white balance setting, there’s a variety of preset white balance modes to choose from plus a custom white balance for calibration to a particular light source. There’s also a new white balance bracketing mode that with just one press of the shutter release will bracket each side of the standard white balance with either a blue/amber bias or a magenta/green bias - clever stuff indeed. Furthermore, the usual set of image processing parameters (contrast, sharpness, saturation, colour tone) are all still available, and are adjustable via the 20D’s menu system. There’s even a new Black & White mode complete with filter and toning effects such as sepia.
The viewfinder on the 20D is clear and has a comfortable rubber eyepiece with a dioptre adjustment wheel located on the top right corner. Looking through the viewfinder you'll see the partial metering circle, as well as the nine illuminated auto focus points arranged in a diamond pattern. Along the bottom of the viewfinder is the illuminated status panel that displays the exposure information along with other settings, although annoyingly the ISO setting is not shown. To find that out you have to take your eye away from the viewfinder, refer back to the top LCD information panel and then press the ‘Drive-ISO’ button.
As far as bundled software goes, the 20D is supplied with several useful applications for both the PC and Mac, including the EOS Viewer Utility and a copy of Adobe Photoshop Elements 2.0. A copy of Canon’s Digital Photo Professional software is included too, which has been designed specifically for browsing and batch processing RAW image files.