The light control system includes command means (640) for outputting a command signal indicating a direction of rotation of the light control means (300), detection means (630) for detecting electromotive force generated in a coil (510), switch means (610) for connecting the coil to drive means (500, 302, 620) in a driving state in which current is supplied to the coil and connecting the coil to the detection means in a non-driving state in which electromotive force generated in the coil is detected, determination means (660) for determining a rotational state of a rotary shaft member (302), based on an output signal output from the detection means, and control means (650) for outputting a command for causing the drive means to output a drive signal, based on an output signal output from the determination means.