To compose photographs with off-center subjects:
Focus: Position the subject in the focus frame and press the shutter button halfway to lock focus and exposure. Focus and exposure will remain locked while the shutter button is pressed halfway (AF/AE lock).
Focus and exposure can also be locked with the [AF-L] and [AE-L] buttons, respectively (if [AE/AF LOCK] is selected for [BUTTON/DIAL SETTING] > [AF-LOCK MODE], pressing the [AF-L] button will lock both focus and exposure).
Recompose: Keep the shutter button pressed halfway or keep the [AF-L] or [AE-L] button pressed.
Focus and/or exposure will remain locked while the [AF-L] or [AE-L] button is pressed, whether or not the shutter button is pressed halfway. If [AE&AF ON/OFF SWITCH] is selected for [BUTTON/DIAL SETTING] > [AE/AF-LOCK MODE], focus and/or exposure lock when the button is pressed and remain locked until the button is pressed again.
Shoot: Press the button all the way down.
The roles of the [AE-L] and [AF-L] buttons can be reversed using [BUTTON/DIAL SETTING] > [AE-L/AF-L BUTTON SETTING].
Autofocus
Although the camera boasts a high-precision autofocus system, it may be unable to focus on the subjects listed below.
Very shiny subjects such as mirrors or car bodies.
Fast-moving subjects.