User Guide

62
AF Mode Selection
AI Servo AF for Moving Subjects
While you press the shutter button
halfway, the camera focuses continu-
ously.
•
This AF mode suits moving subjects when the
focusing distance keeps changing.
•
With predictive AF
∗
, the camera can also focus
track a subject which steadily approaches or
retreats from the camera.
•
The exposure settings are set immediately before
the picture is taken.
•
When focus is achieved in the AI Servo AF mode, the viewfinder’s focus confir-
mation light does not light and the beeper does not sound.
•
If the viewfinder’s focus confirmation light blinks, focus has not been achieved.
•
The focus cannot be locked (except when Custom Function C.Fn-04 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.
With a manually selected AF point, the AF point will flash in red and focus track the subject.
When the AF point selection is automatic, the camera first uses the center AF point to focus. If
the subject later moves away from the center AF point, focus tracking continues as long as the
subject is covered by another AF point in the Area AF ellipse. The active AF point does not
light.
•
You can also change the AI Servo AF's subject tracking sensitivity with C.Fn-20.
(→p.138)
•
With Custom Function C.Fn-04-2, you can lock the focus momentarily by
pressing the <
> button even while the AI Servo AF is active. (→p.133)
•
Custom Function C.Fn-11-2 enables you turn the < > dial to change the AF
point to track the subject in the AI Servo AF mode. (→p.136)