Sony FX 6 Quick Start Manual page 87

Focusing: Total Auto Focus mode
If you have the lens on AF and the Focus switch on the camera on
AUTO, then you are in TOTAL AUTO FOCUS.
In this mode, it is not practical to manually focus. You can push
the PUSH AUTO button on the front of the camera to temporarily
enable manual focus but as soon as you stop pushing it, the
camera goes back to auto focus. It is not practical to keep holding
down this button to manually focus.
So, this mode is for auto focus only.
AUTO on camera.
AF on lens.