Nikon D40 manual Focus Lock, Release button halfway to initiate focus, Ae-L/Af-L

Focus Lock

Controls used Shutter-release button/AE-L/AF-L button

Focus lock can be used to change the composition after focusing, making it possible to focus on a subject that will not be in a focus area in the final composition. It can also be used when the autofocus system is unable to focus ( 27). Single or dynamic area AF is rec- ommended when using focus lock ( 24).

1Focus lock can be used with any focus area. Position the sub- ject in the selected focus area ( 25) and press the shutter-

release button halfway to initiate focus.

2Check that the in-focus indicator (z) appears in the view- finder. Focus will lock automatically when the in-focus indica-

tor appears, and remain locked while the shutter-release button is pressed halfway. Focus can also be locked by press- ing the AE-L/AF-L button while the shutter-release button is pressed halfway. 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.

3Recompose the photograph and shoot.

The shutter-release button can not be used to lock focus in mode ( 19), continuous shooting mode ( 32), or continuous-servo autofocus ( 23), or when continuous-servo autofocus is selected in auto-servo AF ( 23). Use the AE-L/AF-L button to lock focus. At other settings, focus will remain locked between shots if the shutter-release button is kept pressed halfway.

12—AE-L/AF-L ( 77)

This option controls the behavior of the AE-L/AF-Lbutton.

26

Reference: More on Photography (All Modes)/Focus