On a digital SLR camera, an AF (
auto-focus) Servo
refers to the capability of the
camera to
continuously focus on a moving subject. When using the camera, you would
normally press the shutter button to a halfway point, allow the camera's
auto-focus to engage, then press the shutter button all the way down to capture
the subject.
See also auto-focus.
Also see
The Digital
Camera Picture" in Webopedia's
Quick Reference section.