Using Exposure Lock (AE Lock) on the EOS 1Dx Mark III.

Article ID: ART176379 | Date published: 02/03/2020 | Date last updated: 03/20/2020


How to use exposure lock (AE Lock) on the EOS 1Dx Mark III.


Exposure Lock (AE Lock)

Exposure Lock (AE Lock)

You can lock the exposure when you want to set the focus and exposure separately or when you will take multiple shots at the same exposure setting. Press the AE lock button to lock the exposure, then recompose and take the picture. This is called AE lock. It is effective for shooting backlit subjects, etc.

  1. Focus on the subject.

    • Press the shutter button halfway.
    • The exposure value will be displayed.
  2. Press the AE lock button (Timer 06sec).

    • A AE lock icon is displayed in the viewfinder, indicating that the exposure is locked (AE lock).
    • Each time you press the AE lock button, the current exposure setting is locked.
  3. Recompose and take the picture.

    • The AE lock exposure value and current exposure value are shown in real time at right in the viewfinder.
    • When you are to take more pictures while maintaining the AE lock, keep holding down the AE lock button and press the shutter button to take another picture.


  • AE lock is not possible with bulb exposures.

AE Lock Effects

Metering Mode Selection Selecting the AF Area and AF Point
Automatic Selection Manual Selection
Evaluative metering Exposure value centered on the AF point in focus is locked. Exposure value centered on the selected AF point is locked.
Partial meteringSpot meteringCenter-weighted average metering AE lock is applied at the center AF point.

When the Evaluative metering is set and the lens's focus mode switch is set to MF, AE lock is applied with the exposure value weighted on the center AF point.




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