A sensor system includes a sensor array and a gradation determination section. The sensor array includes a first sensor and a second sensor. The first sensor is configured to detect, with a first sensitivity, a variation in a quantity of light at a first pixel address. The second sensor is configured to detect, with a second sensitivity that is lower than the first sensitivity, a variation in a quantity of light at a second pixel address that is adjacent to or coincides with the first pixel address. The gradation determination section is configured to determine, when the first sensor generates a first event signal in response to a luminance variation event, a gradation of an object having caused the luminance variation event to occur, depending on whether or not the second sensor generates a second event signal in response to the luminance variation event.