Owner's Manual

150
Choosing How the Camera Focuses (Focus)
A
Predictive Focus Tracking
In autofocus mode AF-C, the camera will initiate predictive focus tracking
if the subject moves toward or away from the camera while the shutter-
release button is pressed halfway or the AF-ON button is pressed. This
allows the camera to track focus while attempting to predict where the
subject will be when the shutter is released.