Canon EOS 1D Mark III User Guide - Page 16

V. INCOMPARABLE EOS AUTOFOCUS, NOW EVEN BETTER AF System Canon EOS-1 series cameras are legendary for their superior autofocus ability. Many professional photographers rate Canon's autofocus as one of the main reasons that they use Canon equipment. The new autofocus system of the EOS-1D Mark III represents a complete reconsideration of professional autofocus. In addition to a new sensor chip, sophisticated new manufacturing technologies have made it possible to reconfigure the concave submirror and the very clever secondary image formation lens. The result is greater sensitivity, easier and more logical navigation, higher precision and significantly better real-world performance. In the 45-point AF system used by such cameras as the EOS-1v, 1D, 1Ds, 1D Mark II, 1Ds Mark II and 1D Mark II N, there are 7 cross-type, high-precision sensors grouped around the center of the frame. Any of the 45 points could be selected by navigating around the frame. This is the configuration of the previous 45-point AF array: Here is the new AF point layout: Previous 45-point sensor EOS-1D Mark III : Cross-type AF points : Assist points (Not user-selectable) : f/2.8 sensors (Center AF point is f/4) : f/5.6 sensors Note that the 19 high-precision, cross-type points are no longer clustered solely in the center of the frame. The 26 Assist AF points are horizontal-line sensitive at f/5.6, are not user selectable, and operate not only in AI Servo AF mode, but in One-Shot AF as well (C. Fn III-8, 1/2). The Assist AF points achieving focus light up with the super-imposed display (SI). The EOS-1D Mark III features higher precision AF with the 19 user-selectable, cross-type AF points and improved lowlight AF performance. Also, to attain AI Servo AF for 10 fps, the focus computing is faster and an AF adjustment option function is provided. The AF sensor, AF algorithm, and AF-related electronic circuitry have been newly designed especially for the 1D Mark III. Because of improved computing performance and faster reading from the sensor, the AF speed, predictive AF performance, and matching accuracy of the target subject are all the same as with the EOS-1D Mark II N despite the 10 fps continuous shooting speed of the 1D Mark III. Of course, at 8.5 fps, the 1D Mark II N was no slouch itself. V. INCOMPARABLE EOS AUTOFOCUS, NOW EVEN BETTER 16