Both Full-time AF and Subject tracking AF continue focusing a subject captured in the wide focus area. The differences are as follows. Full-time AF: The camera immediately starts focusing when turned on and continues focusing without the shutter-release button pressed. The focus area is not displayed. Subject tracking AF: The camera starts focus when the shutter-release button is presed partway down and keeps on focusing the subject as long as the buttin is held. The focus area is displayed.