An imaging system includes a first illuminator that emits light whose intensity varies with time; and a first imaging device that comprises a first imaging cell; and a first bias control line. The first imaging cell includes a first electrode, a second electrode electrically connected to the first bias control line, and a photoelectric conversion layer sandwiched between the first electrode and the second electrode. During a first period from a reset of the first imaging cell until a readout of signal charge accumulated in the first imaging cell, the first bias control line supplies to the second electrode a first bias control signal. The first bias control signal is synchronized with the intensity of the light varying with time.