Auto Lighting Optimizer on Canon EOS Rebel T3 Series Cameras
The Auto Lighting Optimizer on your Canon Rebel T3 or T3i adjusts both shadows and highlights to improve the final image tonality (range of darks to lights). In other words, it’s a contrast adjustment.
In the fully automatic exposure modes as well as in Creative Auto, you have no control over how much adjustment is made. But in the other five exposure modes — P, Tv, Av, M, and A-DEP — you can decide whether to enable Auto Lighting Optimizer. You also can request a stronger or lighter application of the effect than the default setting.
Given the level of improvement that the Auto Lighting Optimizer correction made to this photo, you may be thinking that you’d be crazy to ever disable the feature. But it’s important to note a few points:
The level of shift that occurs between each Auto Lighting Optimization setting varies dramatically depending on the subject. This particular example shows a fairly noticeable difference between the Strong and Off settings. But you don’t always see this much impact from the filter. Even in this example, it’s difficult to detect much difference between Off and Low.
Although the filter improved this particular scene, at times you may not find it beneficial. For example, maybe you’re purposely trying to shoot a backlit subject in silhouette or produce a low-contrast image. Either way, you don’t want the camera to insert its opinions on the exposure or contrast you’re trying to achieve.
Because the filter is applied after you capture the photo, while the camera is writing the data to the memory card, it can slow your shooting rate.
In some lighting conditions, Auto Lighting Optimizer can produce an increase in image noise.
The corrective action taken by Auto Lighting Optimization can make some other exposure-adjustment features less effective. So turn it off if you don’t see the results you expect when you’re using the following features:
Automatic exposure bracketing
By default, the camera applies the Auto Lighting Optimizer feature at the Standard level. If you want to experiment with other settings, you can do so via Shooting Menu 2 or the Quick Control screen. Notice the little vertical bars that appear as part of the setting icon — the number of bars tells you how much adjustment is being applied. Two bars represent the Standard setting; three bars, Strong, and one bar, Low. The bars are replaced by the word Off when the feature is disabled.
If you’re not sure what level of Auto Lighting Optimization might work best or you’re concerned about the other drawbacks of enabling the filter, consider shooting the picture in the Raw file format. For Raw pictures, the camera applies no post-capture tweaking, regardless of whether this filter or any other one is enabled. Then, by using Canon Digital Photo Professional, the software provided free with the camera, you can apply the Auto Lighting Optimizer effect when you convert your Raw images to a standard file format.