曝光补偿也称为EV（曝光值）调整，是指在摄影过程中通过对曝光值的调整以达到最佳效果的一种技术手段。虽然有些照相机能够自动运算得出曝光值，但是得到的未必绝对正确，而且也可能不是拍摄者所想要的。这时拍摄者可以根据需要调整曝光补偿。曝光补偿增加1EV，相当于曝光值（EV）减少1，即进光量增加一倍，可以使图像更亮；反之则图像会更暗。

曝光值的改变是通过改变f值和快门速度来实现的。如果相机采用光圈优先模式，则改变的是快门速度；如果相机采用快门优先模式，则改变的是f值。

未使用曝光补偿

曝光补偿+2EV

Exposure compensation is a technique for adjusting the exposure indicated by a photographic exposure meter, in consideration of factors that may cause the indicated exposure to result in a less-than-optimal image. Factors considered may include unusual lighting distribution, variations within a camera system, filters, non-standard processing, or intended underexposure or overexposure. Cinematographers may also apply exposure compensation for changes in shutter angle or film speed (as exposure index), among other factors.