Using the AF-C and AF ON method is no solution for D800.

The only way to have a STATIC subject is with an object with no motion at all AND the camera to be on a tripod.

Shooting a posing person with a handheld D800 still produces motion relative to the camera. In fact shooting ANYTHING handheld will have some motion relative to the sensor.

So AF-C would be best used with any handheld shooting as it constantly attempts to refocus.

Robert