When shooting in AUTO mode, the camera usually sets the optimum exposure value (EV) automatically. However, black subjects and white subjects have a different reflectance even when exposed to the same amount of light - the amount of light received by the exposure meter is different. This may cause the exposure meter to judge a white subject as a bright location or a black subject as a dark location, regardless of the scene, and set the wrong exposure.
In these types of situations, manually adjust the exposure compensation. Adjust the exposure in the plus (+) direction when shooting white or backlit subjects. Adjust the exposure in the minus (-) direction when shooting black subjects.
NOTE: Refer to the instruction manual of your camera for complete information. Manuals are posted on your model support page.