A luminaire comprising: at least one light source for emitting light to illuminate an environment; an optical sensor comprising an array of photodetectors, the sensor configured to output image data indicative of the intensity of light incident on the photodetectors; and a controller arranged to receive the image data, the controller comprising: a presence detection module configured to process the image data to detect whether a being is present in said environment, and control the light emitted by the light source(s) responsive to said detection; a light sensing module configured to process the image data to determine a light level in said environment and control the light emitted by the light source(s) based on said light level; and a commissioning module configured to control the controller to operate in a commissioning mode based on the image data; and configure the luminaire in accordance with a commissioning command received whilst the controller is operating in the commissioning mode.