An apparatus and method for measuring spatially varying bidirectional reflectance distribution function and method are provided. The apparatus and method provide means to illuminate different areas of a sample at different angles of incidence and detect the angular variation of radiation emitted from the sample in response to the illumination. The apparatus includes a paraboloidal reflector for delivering the illumination and receiving the radiation emitted by the sample, a radiation source for generating a beam of collimated radiation, a beam steering device for controlling the angle of incidence with which the focused cone of light strikes the sample, and a detector to receive the collected light from the reflector.