A method of calibrating an autofocus (AF) lighting device of a camera is disclosed. A reference image is captured with light projected from the AF lighting device, and a relative position of a central coordinate of the projected light with respect to a central coordinate of the reference image is stored. When operating the camera, the AF lighting device is activated to emit light after a shutter button of the camera is pressed halfway down, and a preview picture is displayed on a panel of the camera. A central position of the emitted light is then transposed toward a center of the panel according to the stored relative position.