In this lesson: Discover how to override your camera’s exposure system to adjust for challenging lighting conditions

By learning how to use exposure compensation on your camera, you can more effectively correct for lighting conditions that cause errors in exposure. In other words, mastering exposure compensation gives you more power to determine how your images are exposed.

There are many conditions that can “fool” your camera’s exposure metering system. This can lead to unwanted results when taking photos under those conditions. Fortunately, most digital cameras provide exposure compensation to allow you to override the default setting for the metering system. In tricky lighting situations, this feature allows you to continue to use the current autoexposure mode while overriding the setting that the camera is currently controlling. For example, when shooting in aperture priority mode, the camera will apply the correction you’ve dialed in by adjusting the shutter speed accordingly. Conversely, when shooting in shutter priority, the camera corrects the exposure by adjusting the aperture.

Strong backlighting is one of the most common situations that can confuse the camera’s exposure system. For example, using a typical averaged exposure in the situation above, where the subject is in front of a strong backlit light source like the sun, your subject might appear as a silhouette due to underexposure. In other words, your camera’s meter reads the scene as being very bright as a result of all the light in the background, even though the subject isn’t bright at all. The result is a portrait in which the subject is fairly deeply silhouetted.

Exposure compensation can correct this by allowing you to force the camera to overexpose the overall scene, resulting in a better exposure for the subject. Exposure compensation allows you to make subtle adjustments to strike a balance between the bright and dark areas of the scene, as seen in the image below. Note the difference between the image above and the image below. Below, the woman is well-exposed so we can see her facial features, whereas the woman above is quite dark, making the details of her face more difficult to see.

Exposure compensation adjustments are made in increments of partial stops, on a scale that typically reads from -2 or -3 to +2 or +3, with an indicator that reads zero in the center serving as the default setting. Moving the indicator to the right increases the exposure, thereby lightening the photo and, of course, moving it to the left decreases the exposure, thereby darkening the photo.

Note: Cameras differ on how the exposure compensation feature is accessed. Furthermore, cameras differ regarding how this feature is adjusted as well. Refer to the camera’s owner’s manual for instructions for your specific camera.

Challenge Activity

This activity requires you to work with a high-contrast lighting situation in which you capture several images while using various exposure compensation settings.

Step 1: Invite a patient friend or model to pose for backlit portraits. Plan a shoot in the morning or evening, when the low sun can be used for backlighting.

Step 2: Set your camera to aperture priority mode and select an aperture toward the low midrange of your lens, for instance, f/5.6 to f/8. Dial in a low ISO setting as well, like ISO 100 or ISO 200.

Step 3: Verify that exposure compensation is set to 0. Place your subject between you and the sun, but don’t shoot directly into the sun lest you risk damaging your camera and lens.

Step 4: Take a series of shots, starting at zero exposure compensation, then moving to the negative side down to a couple of stops. Then, work your way back to the positive side of the exposure compensation scale up to a couple of stops. Compensate in whatever increments you like, but be consistent in order to gauge the effect from one image to the next most accurately.

Step 5: Review and evaluate the results of the series. You should find that the images taken using negative exposure compensation will be darker, while at least one of the images taken with positive exposure compensation will reveal the features in your model’s face while retaining the effects of the strong backlight, as is seen in the image of the man above.