Much like the D90, the D5000 can only use contrast-detection AF (using the main imaging sensor) in live view - there's no option to use the camera's phase-detection AF sensor. The advantage is that the AF point can be moved anywhere in the frame, and can do exciting things such as detecting faces and tracking subjects in ways that a conventional DSLR AF sensor simply can't.
The disadvantage is that it's terribly slow when compared to conventional DSLR (phase-detection) AF or to contrast detection AF in compact cameras. This is a problem that no DSLR has yet entirely resolved without introducing other compromises (and one that may well require designed-for-contrast-detection lenses, as Panasonic has done with its G Micro System cameras).
The D5000's latest trick is the addition of a subject tracking AF mode. Sadly, although this does a great job of following a subject, even if it briefly leaves the frame, it doesn't actually adjust the focus as it tracks (probably because the battery drain would be punitive). The result is that it knows exactly where it'll need to start focusing, but hasn't done anything to shorten the time taken to find focus.
Live view display modes
Press the info button to change the overlaid information, you can also optionally enable grid lines which are in the same position as the grid lines shown on the viewfinder focusing screen.
|Info panel is now available in live view||Live view with shooting info.|
|Plain display||Optional grid lines|
|In wide or normal area AF the AF point can be moved around the screen||Pressing the magnification button zooms in on wherever the AF point is.|
|Half-pressing the shutter begins the AF sequence and the AF point, whether zoomed or not, will light green when focus is acquired.|
Live view auto focus
The following video clips shows live view in use to auto-focus, magnify live view, take an exposure and finally magnify the image in record review.
Please note that the following video has been taken from our D3 review (the focusing sequence on the D5000 is virtually identical to the D3).
Autofocus in Live View
Overall handling and operation comments
The D5000 is a slightly odd fish when it comes to handling and operation. Despite it's rather lumpy-bumpy cobbled-together appearance, the D5000 fits very comfortably in the hand. The rear dial and exposure compensation button are both within easy reach, making shooting a quick, comfortable and immersive experience (you don't have to take your eye away from the viewfinder if you're making little tweaks to your exposure settings). You also have constant access to AF-point selection, via the control pad on the back of the camera - so long as you're in an AF-point selection mode that requires manual input.
However, this permanent use of the control pad means that there are very few external controls left for directly accessing shooting settings - forcing you to use the interactive info panel. This is not a terrible situation - the info panel is clear and simple to use - but lordy, there's a whole heap of button pressing to be done. If you're used to using a compact camera, this process is likely to be instantly familiar (perhaps even welcoming), but it's not as quick as using the direct access buttons on the Canon EOS 500D, Olympus E-620 or Nikon D90, once you've got used to that way of working.
Ultimately, it's a question of taste. We found that assigning ISO to the self-timer/function button (custom setting f1), allowed all three fundamental shooting parameters (shutter speed, aperture and ISO), to be set with your eye to the viewfinder while in P,A or S mode, which is key to quick shooting. Beyond that, the button pressing to scroll through and select options from the control panel can get a bit wearing but it's generally still easier than on previous generations of entry-level camera and is unlikely to be objectionable to the key audience for this camera.