This picture turned out really well:
and here Lila is running towards the camera, and the aperture is wide open. I know the AF system uses the phase of light and diffraction to work out when it is in focus, but the time it takes to raise the mirror is surely at least 50ms the subject can move in this time.
So my question is this, does the AF system understand velocity and assume it is linear at the instant it starts to raise the mirror?
I've deliberately not mentioned my camera, because I am curious about AF as a system rather than specific to one camera.
The camera raises the mirror and sets the aperture when it takes a picture, and with the mirror raising or raised, the AF system no longer works, so it can't know it is in focus.