An image sensor includes: a first pixel having a first photoelectric conversion unit that generates an electric charge through photoelectric conversion of light, and a first output unit that generates a first signal based upon the electric charge generated by the first photoelectric conversion unit and outputs the first signal; a second pixel having a second photoelectric conversion unit that generates an electric charge through photoelectric conversion of light, and a second output unit that generates a second signal based upon the electric charge generated by the second photoelectric conversion unit and outputs the second signal; and an adjustment unit that adjusts a capacitance at the first output unit upon outputting of the first signal and the second signal from the first output unit.