Canon EOS-1D C EOS 1D X Instruction Manual - Page 90

3 Selecting AI Servo AF Characteristics (For a Subject) AF point auto switching This sets the switching sensitivity of the AF points as they track a subject that moves dramatically up, down, left, or right. This setting takes effect in the following AF area selection modes: AF point expansion (Manual selection ), AF point expansion (Manual selection, surrounding points), Zone AF (Manual selection), 61-point automatic selection AF. [0] Standard setting for gradual AF point switching. [+2 / +1] Even if the target subject moves dramatically up, down, left, or right and moves away from the AF point, the AF point switches to another one to continue focusing the subject. The camera switches to the AF point deemed most likely to focus the subject based on the subject's continual movement, contrast, etc. Setting +2 makes the camera more prone to switch the AF point than with +1. However, with a wide-angle lens having a wide depth of field or if the subject is too small in the frame, the camera may focus with the wrong AF point. 90