The EOS-1D Mark III raises the bar for AF performance. It uses an extraordinary 45-point high-density area AF system that provides not only the industry's largest continuous AF coverage area, but also the greatest range of control over focusing point selection. The focusing point can be selected automatically by the camera (based on high-speed microcomputer analysis of image content), or users can manually select any of 19 high precision, cross-type AF points which can be complemented by 26 additional Assist Points for pin sharp accuracy, instantaneously.
A processing unit devoted solely to focusing the 1D Mark III uses advanced algorithms that ensure the fastest, most accurate AF performance under the widest variety of conditions, with processing up to 3x faster and a full stop darker than on the EOS-1D Mark II N. The One-Shot AF mode is ideal for more static subjects. The camera rapidly selects the optimum focusing point and the subject is instantly brought into focus even if it is off-center. The AI Servo AF mode is excellent for moving subjects. Aided by a highly "intelligent" predictive focusing algorithm, it precisely tracks subject movement, even at speeds of up to 10 fps. Even with erratic or rapid subject movement, the photographer can shoot continuously, concentrating solely on image composition.
New Custom Functions aid the photographer in choosing from default focusing points, as well as changing the size of a manually-selected AF point, making this not only the fastest, but also the most customizable AF system on the planet.