A solid-state image sensor has a pixel array and a processor configured to process a signal from the pixel array, the pixel array including a light-receiving pixel having first and second photoelectric converters and a light-shielded pixel having third and fourth photoelectric converters. The processor outputs (a) a pixel signal corresponding to charges of the first photoelectric converter, (b) an added pixel signal corresponding to a sum of charges of the first photoelectric converter and charges of the second photoelectric converter, and (c) an added reference signal corresponding to a sum of charges of the third photoelectric converter and charges of the fourth photoelectric converter, and does not output (d) a reference signal corresponding to charges of the third photoelectric converter and a reference signal corresponding to charges of the fourth photoelectric converter.