Canon EOS-3 manual AI Servo AF for Moving Subjects, About Predictive AF

AF Mode Selection

AI Servo AF for Moving

Subjects

While you press the shutter button halfway, the camera focuses continuously. This AF mode suits moving subjects. With predictive AF, the camera can also focus track a subject which steadily approaches or retreats from the camera. The exposure setting are set immediately before the picture is taken.

•In the AI Servo AF mode, the viewfinder’s in-focus indicator does not light and the beeper does not sound even when focus is achieved.

•If the viewfinder’s in-focus indicator blinks, focus cannot be achieved.

•The focus cannot be locked (except when Custom Function CF-4 is set to 2.)

*About Predictive AF

If the subject approaches or retreats from the camera at a constant rate, the camera tracks the subject and predicts the focusing distance immediately before the picture is taken. This is for obtaining correct focus at the moment of exposure.

When focusing point selection is automatic, the camera first uses the center focusing point to focus. If the subject later moves away from the center focusing point, focus tracking continues as long as the subject is covered by another focusing point in the area AF ellipse. The active focusing point does not light.

CF

CF

With Custom Function CF-4, you can lock the focus momentarily by pressing the < > button even while the AI Servo AF is active. See page 108.

Custom Function CF-11 enables you turn the < > dial to change the focusing point to track the subject in the AI Servo AF mode. See page 116.

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