91f: Changing the Autofocus OperationKSuited for still subjects. When youpress the shutter button halfway, thecamera will focus only once. When focus is achieved, the AF pointthat achieved focus will be displayed,and the focus indicator <o> in theviewfinder will also light up. With evaluative metering, theexposure setting will be set at thesame time focus is achieved. While you hold down the shutter button halfway, the focus will belocked. You can then recompose the shot if desired.This AF operation is suited for moving subjects when the focusingdistance keeps changing. While you hold down the shutter buttonhalfway, the subject will be focused on continuously. The exposure is set at the moment the picture is taken. When the AF area selection mode is set to 19-point automaticselection AF (p.93), the camera first uses the manually-selected AFpoint to focus. During autofocusing, if the subject moves away fromthe manually-selected AF point, focus tracking continues as long asthe subject is covered by the Area AF frame.AI Focus AF switches the AF operation from One-Shot AF to AIServo AF automatically if a still subject starts moving. After the subject is focused on in One-Shot AF, if the subject startsmoving, the camera will detect the movement, change the AFoperation automatically to AI Servo AF, and start tracking the movingsubject.One-Shot AF for Still SubjectsFocus indicatorAF pointAI Servo AF for Moving SubjectsAI Focus AF for Switching the AF Operation Automatically
