Nikon D3000 User Manual page 50

IIAE-L/AF-L
Choose the role played by the AE-L/AF-L button.
AE-L/AF-L button
Option Description
I_ AE/AF lock Focus and exposure lock while the AE-L/AF-L button is pressed.
!_ AE Iockonly Exposure locks while the AE4./AF-L button is pressed.
AF lock only Focus locks while the AE4./AF-L button is pressed.
Exposure locks when the AE-L/AF-L button is pressed, and remains locked
!_@ AE lock (hold) until the button is pressed a second time or the exposure meters turn
off.
The AE-L/AF-L button initiates autofocus. The shutter-release button can
AF-ON
not be used to focus.
IIAE Lock
At the default setting of Off, exposure only locks when the AE-L/
AF-Lbutton is pressed. If On is selected, exposure will also lock
when the shutter-release button is pressed halfway.
135