Pressing the shutter-release button halfway initiates autofocus. Focus mode lets you choose whether focus locks once the camera has focused or if the camera continues to adjust focus while the shutter-release button is pressed halfway.
AF-S(Single-servo):
AF For stationary subjects. Focus locks when shutter-release button is pressed halfway.
AF-F(Full-time servo AF):
For moving subjects. Camera focuses continuously until shutter-release button is pressed. Focus locks when shutter-release button is pressed halfway.
MF(Manual focus):
Focus manually.
02. Highlight the current focus mode in the information display with the multi selector and press OK.
03. Highlight a focus mode and press OK.