Autoexposure Lock - Nikon D5100 Reference Manual

Autoexposure Lock

Use autoexposure lock to recompose photographs after using M (Center-weighted
metering) and N (Spot metering) to meter exposure; note that autoexposure lock is
not available in i or j mode.
1
Meter exposure.
Position the subject in the center of the frame
(center-weighted metering) or the selected
focus point (spot metering) and press the
shutter-release button halfway to set focus and
meter exposure. Check that the in-focus
indicator (I) appears in the viewfinder.
2
Lock exposure.
With the shutter-release button pressed halfway and the
subject positioned in the focus point, press the AE-L/AF-L
button to lock exposure.
A
Autoexposure Lock
If On is selected for Custom Setting c1 (Shutter-release
button AE-L; 0 159), exposure will lock when the shutter-
release button is pressed halfway. For information on
changing the role of the AE-L/AF-L button, see Custom Setting f2
(Assign AE-L/AF-L button; 0 166).
While exposure lock is in effect, an AE-L indicator will
appear in the viewfinder.
3
Recompose the photograph.
Keeping the AE-L/AF-L button pressed, recompose
the photograph and shoot.
A
Adjusting Shutter Speed and Aperture
While exposure lock is in effect, the following settings can be adjusted without altering the
metered value for exposure:
Mode
Programmed auto
Shutter-priority auto
Aperture-priority auto
The metering method itself can not be changed while exposure lock is in effect.
Shutter speed and aperture (flexible program; 0 62)
Shutter speed
Shutter-release
AE-L/AF-L button
Setting
Aperture
button
t
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