A method to calibrate an imaging array of a time-of-flight depth camera includes the act of modulating emission from a light source of the camera while synchronously biasing the imaging array. In this method, the modulated emission reflects from a compact reflector positioned a known distance from the camera and passes through an optical diffuser en route to the imaging array. For each pixel of the imaging array, a correction term is stored, which brings the output from that pixel into agreement with the actual distance between the camera and the compact reflector.