Autofocus
As a compact camera, the PowerShot G12 relies on contrast-detection autofocus, and this remains unchanged from the G11. The AF is fast enough for point-and-shoot photographers and great for holiday pictures and days out, but it isn?t quite as snappy as some of the other contrast-detection AF systems we have seen recently. However, low light is one area in which the AF system performs especially well. The on-screen image brightens when low light is detected, and this amplification in signal obviously helps the camera focus. There is also a blue LED AF assist light, which discreetly comes on, even when the light is only slightly dim, to help the lens focus.
There are enough AF options in the G12 to keep enthusiast photographers happy. There are two different AF point sizes available for selection, with 493 selectable points when it is set to the smaller of the two sizes. To assist the tracking of moving subjects is the AF Tracking mode. This allows a subject to be selected and then tracked around the frame should it or the camera move. I found this works well and should be ideal when photographing children, animals or other similar subjects.
For social situations the Face Detection AF is useful, working in a similar fashion to the AF Tracking mode but detecting faces instead, which it then focuses on and tracks. Again, this was a feature included in previous PowerShot G-series models.
Manual focusing is also possible on the G12, using the scroll dial to focus the lens back and forth. Although a magnified view is displayed in the centre of the screen when in manual focus mode, I found that it was still difficult to ascertain the correct point of focus precisely. For the most part I would say that manual focus is not really beneficial, and the sheer number of AF points and the close 1cm macro mode make it somewhat redundant.
As a walk-around camera, designed for holidays and days out, the AF of the G12 has enough modes to keep enthusiast photographers happy.
