So what is AFr mode?
As you are probably aware, whenever you focus on a point and then move to recompose your image the plane of focus will change, and likely what you focussed on is no longer in the plane. The typical example of this is focussing on your subject's eye using a centre focus point, then recomposing them for framing so their eyes are now toward the top of your image. What you find is their eyes have fallen forward of the plane of focus, with their ears being very very sharp - not ideal!
Phase One have updated the XF Camera with a new feature that uses the built in gyroscopes and accelerometers in the camera to measure and predict the movement you make between the moment you lock focus, and press the shutter.
In this way it is incredibly good at learning (yes learning!) your movement during a shoot and accounting for it... So that little bit of body sway you make as you breath in and out, as well as moving the camera to recompose are accounted for.
During use there is a fantastic audio feedback given by the camera: a chirpy positive sounding beep to reinforce to you when it has tracked your movement successfully, and a negative sounding one that tells you it has not.
Typically we have found on the very first shot you make it won't successfully track your movement, but after that it does. Don't ask us how but according to Phase One it "learns" your movement in each shot setup. The other time it gives you the negative beep is when you actually move so far that the original focus point is no longer in the frame or when your movement is too violent or inconsistent.
