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).
[AEL/AFL] button. The role played by the [AEL/AFL] button can be chosen using [BUTTON/DIAL SETTING] > [FUNCTION (Fn) SETTING]: choose from [AE LOCK ONLY] (pressing the [AEL/AFL] locks exposure but not focus), [AF LOCK ONLY] (pressing the [AEL/AFL] locks focus but not exposure), and [AE/AF LOCK] (pressing the [AEL/AFL] locks both focus and exposure).
Recompose: Keep the shutter button pressed halfway or keep the [AFL/AEL] button pressed.
Focus and/or exposure will remain locked while the [AFL/AEL] 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.
Although the camera boasts a high-precision autofocus system, it may be unable to focus on the subjects listed below.