Locking Exposure Separate from Focus

On cameras with auto focus and auto exposure, pressing the shutter button half way sets both exposure and focus. But what if you want to adjust the exposure from what the camera chooses without changing what the camera focuses on?

Auto Exposure Lock (AE-L) comes to the rescue. In Program, Aperture Priority, and Shutter Priority exposure modes, you can use the AE-L button (sometimes a * button) to make the camera remember the exposure while you recompose and focus on the subject. In the following pictures, I used Auto Exposure Lock to remember the exposure for different parts of the scene.

In the first photo, I pointed the camera at the sunlit snow and pressed the shutter halfway to set the exposure. Then I pressed the AE-L/* button to make the camera remember the exposure. In the viewfinder, an AE-L or * symbol appeared to show the camera was remembering the exposure. Then I recomposed the scene, pressed the shutter button halfway again to focus on the wall and took the photo. This preserved detail in the bright snow but left the shaded wall dark.

Auto Exposure Lock (AE-L/*) on sunlit snow

In the second photo, I pointed the camera at the shaded wall and used the AE-L/* button to lock the exposure on the wall. The wall became brighter but the snow overexposed.

Auto Exposure Lock (AE-L/*) on shaded wall

Using the AE-L/* button gave me two pictures with the same composition and focus but different brightnesses.

Learn about more camera controls in Taking the Next Step with Your Digital Camera, March 28, 2026, at the Lifelong Learning Center in Missoula, Montana. Click here for registration information.