Nikon D3100 - Manual (Page 77)

61
z
2
Lock focus.
AF-A and AF-C focus modes : With the shutter-release
button pressed halfway (q), press the AE-L/AF-L
button (w) to lock both focus and exposure (an
AE-L icon will be displayed in the viewfinder;
0 80). Focus will remain locked while the AE-L/AF-
L
button is pressed, even if you later remove your
finger from the shutter-release button.
AF-S focus mode : Focus will lock automatically when the in-focus indicator
appears, and remain locked until you remove your finger from the shutter-
release button. Focus can also be locked by pressing the AE-L/AF-L button (see
above).
3
Recompose the photograph and shoot.
Focus will remain locked between shots if you
keep the shutter-release button pressed halfway
(AF-S) or keep the AE-L/AF-L button pressed,
allowing several photographs in succession to
be taken at the same focus setting.
Do not change the distance between the camera and the subject while focus lock is
in effect. If the subject moves, focus again at the new distance.
A
The AE-L/AF-L Button
The Buttons > AE-L/AF-L button option in the setup menu ( 0 146) controls the behavior of
the AE-L/AF-L button.
Shutter-release button
AE-L/AF-L button