AE Lock Button: a Quick and Easy Way to Adjust Exposure
Correct exposure of a highly contrasted scene can be tricky to handle, especially if you are taking some photos on the go and do not have time to stop and think twice about the camera settings. There are various ways to adjust the exposure, such as using exposure compensation or center weighted metering. In some situations, however, every moment counts, and you may need a quick and easy solution to get your image right. This is where the exposure lock button on your DSLR camera may prove helpful. Let's see how to quickly and easily adjust the exposure on the go without touching any of the camera settings other than the exposure lock.
As a starting point, this is an image of a contrasted Parisian street scene with a blooming tree. In the upper part of the image, the tree and the surrounding buildings are in bright sunlight, while the street with the line of parked bikes in the lower part of the photo is hiding in deep shadows, thus making it difficult to discern the details. My attention went to the blooming tree; I wanted to show it in the context of the street: tender purple flowers against strong architecture and a line of repetitive robust black scooters.
Since I wanted to show the details in both parts of the image and the light was not easy to handle, I needed to find a solution. Several options came to my mind: (1) to come back in a different time of the day; (2) to skip the street by pointing the camera upwards, exposing only for the sunny part with the tree (however, in that case it will be a different photo); (3) to use exposure compensation (+/- button); (4) to switch to centre-weighted metering mode. But let's say you are on the go and need to take that photo before quickly moving on. One of the quickest and easiest solution in such a case is to use the exposure lock button, or the so-called AE lock button.
The AE lock button is usually located on the right side at the back of your camera. On Canon cameras, it is marked with an asterisk (*):
On Nikon cameras, the button at the back of the camera is usually marked as AE-L/AF-L and can be programmed to either exposure lock (AE-L) or focus lock (AF-L) function (refer to your camera manual for more information).
So how does that work? The AE lock button freezes whichever exposure parameters were set by your camera until you take a picture. Therefore, in order to quickly correct the exposure of the scene and to bring more light into the image, simply point the camera to a darker spot in the foreground, let it measure the light and adjust the settings to add more light in the image, then press the AE lock button and hold it down while recomposing the image. Then press the shutter release and you're done! Similarly, to darken the scene, point the camera to a brighter spot, hold down the AE lock button, recompose and take a photo. This easy technique will work in Program, Aperture Priority or Shutter Speed priority modes, but will not apply in fully automatic or fully manual modes of your camera.
You may practice this technique a few times at home while reading this article before heading into the streets with your trusty camera, and you will quickly see how simple it is to use the AE lock button for an easy exposure adjustment.
Finally, this is the resulting image of the same scene with the blooming tree that caught my eye: while I was correcting the exposure, a few passers-by appeared in the scene and added some life and interest to the image!
Try using the AE lock button on your camera, let us know if this works for you and share your photos with us!
About the Author
Nadia is passionate about the visual aspect of life and the personalities she meets along the way. Living in the heart of Paris, Nadia never stops exploring the City of Light through her camera and readily shares her knowledge and love for photography.