To me, the exposure compensation control is one of the most important parts of a digital SLR or mirrorless camera and it’s the first control—after how to adjust ISO setting—that I look for on a new camera.
It’s always been my belief that camera’s designers realized that no amount of automation will produce a “perfect” exposure under all possible lighting situations and what some people might like others might not. Since you are the final arbiter of what’s “correct” the Exposure Compensation feature lets you increase or decrease the automatic exposure by one-half or one-third tops to get exactly the exposure you like. Using the camera’s LCD screen and histogram function will help you home in on what’s “correct.”
Controlling exposure compensation usually this involves pressing a button and rolling a control wheel and because no two cameras—even form the same manufacturer— do it the same way, refer to your User’s Guide for specific directions for your SLR. On my Panasonic Lumix G5 it’s a small toggle next to the shutter release but none of my other Lumix camera do it that way, a shame really. Tip: If you can set the amount of compensation by one-half or one-third, use the one-third stop option because it provides you with more options and allows a more nuanced difference in exposure.