I'm lucky enough to be testing Canon's EOS 5D Mark III this week and I took it with me to the Hunter Valley on the weekend. The sensor is 22.3 megapixels with an ISO range of 50-102,400, but more importantly, the camera has greatly improved image quality at the higher ISO settings. Like the Nikon D800E, I am loving the fact I can set the ISO to Automatic and feel comfortable that even at higher ISO settings I will be more than happy with the quality.
While running the portraiture workshop on the weekend, I discussed the importance of using the autofocus system with a single AF gunsight for precise focusing on the eyes.If you are using a wide-area autofocus set up, where the camera reads a number of different focus points and chooses what it thinks is the most appropriate, you may find you are not focused on the eyes of your subject. Chances are the camera has selected the ears or the tip of the nose instead.
To ensure you are focusing on the eyes, especially when using wide apertures (and shallow depth-of-field), it is much better to switch to a single autofocus point. Even so, the camera can sometimes choose to focus on the eye lashes rather than the eye itself, depending on the lens and how close you are to the subject..
One of the attendees, Phil McFadden, pointed out that the later Canon cameras (such as the 7D and 5D Mark III) offer a spot autofocus mode.This mode uses just the middle of an autofocus gunsight (or focusing point), as shown by a small square inside the focus point rectangle. In this way, you can improve your chances of achieving really precise autofocus, exactly where you want it. Very handy when shooting with Canon's wide aperture primes lenses, like the 50mm f1.2 and 85mm f1.2.