1. In video teleconferencing, the light from a nonselective diffuse reflector (in the original scene) that is lighted by the normal illumination of the scene; i.e., that white with which the display device simulates reference white of the original scene. 2. In the context of video production, the luminance of a white card having 90% reflectance, and subjected to scene illumination. Note: Usually there will be some discrimination of surface texture or detail within that portion of the transfer function incorporating reference white.