Sony FX 6 Quick Start Manual page 94

Focusing: Difference in Auto Focus Tracking
when in Hybrid Focus and Total Auto Focus
There is a major difference between auto focus tracking in hybrid focus mode and
total auto focus mode.
The settings I have chosen in Menu/Shooting/Focus give you a choice of how you
want to handle the auto focus tracking by selecting Hybrid or Total Auto focus.
Menu/Shooting/Focus/Face/Eye Priority AF: with this selected (this is the default
setting), the camera will automatically track faces and eyes in the frame when in
TOTAL AUTO FOCUS. People will automatically become the "focus".
See the next page for a more detailed explanation.