Operation and controls
Top of camera controls
The top plate plays host to the camera's major controls. Immediately behind the shutter button is the command dial that, in concert with the +/- button on the rear, is used for changing the main exposure parameters (shutter speed, aperture and exposure compensation). Behind this are two large, prominent buttons; 'DISP' for switching the rear LCD on and off, and 'ISO'. The latter is particularly well-placed for operation with the camera to your eye; simply press the button then spin the command dial to change the sensitivity (which is permanently displayed in the viewfinder).
The large exposure mode dial offers a full range of auto and manual options - this is also your port of call when shooting video, as you have to explicitly set the camera to movie mode (on the whole we prefer cameras that have direct record buttons which work in all exposure modes). It's surrounded by the large, positive on/off switch.
Rear of camera controls
The rear of the camera is laid out pretty well identically to the 550D. The button shapes are more stylized, and the four-way controller is a little bit smaller, but overall Canon has stuck to its tried-and-tested layout. This angle also emphasizes the deeply-sculpted channel that provides a positive grip for your thumb.
Canon has clearly set the 600D up to be controlled as far as possible by the right hand, and three key shooting controls - autoexposure lock (*), AF point selection and exposure compensation (+/-) are all placed within easy reach of your thumb. The latter has also moved slightly away from the viewfinder, making it a little more accessible, but it's still all-too-easy to hit the Q button below it by mistake. However he need to press a button to enter AF point selection mode, then the 4-way controller to select the required point, makes this process slightly more fiddly than on competitors which use the controller directly (but in turn sacrifice some other external controls).
The 'red dot' button beside the viewfinder has two functions. In movie mode, it starts and stops recording, whereas in all other modes it's used to enter or exit live view. The four-way controller provides direct access to white balance, focus and drive modes, and picture style during normal shooting, but there's no hard button for metering mode. However this is still relatively easy to set using the 'Q' button, which 'activates' the rear control panel to allow quick access to pretty well anything else you'd like to change while shooting.
When you switch to Live View or Movie shooting, the 4-way controller buttons no longer operate their marked functions, but are used directly to move the AF point around the frame (with WB etc now accessed via the Q button). We found this mode change somewhat disconcerting, and more than once ended up inadvertently changing the AF point position when we really wanted to set the white balance or drive mode.
Front of camera controls
The 600D's external controls are rounded-off by two buttons on the lens throat. The upper of the two is used to raise the flash in the P, Av, Tv and M modes (in the others it pops up automatically), but sadly doesn't do anything else, for example set flash exposure compensation. The lower button, just below the lens release, is the depth of field preview - press this to stop down the lens to the working aperture and see the effect in the viewfinder. Unlike some cameras, this also works perfectly sensibly in live view, where the much brighter, clearer view makes it far easier to judge what's going on.