The quantity of luminance is used to evaluate the photometric brightness of light from surface emitters. In many cases luminance describes the quality of illumination much better than does illuminance. Luminance is measured in the (SI) photometric unit of candela per square meter (cd/m2) or foot-lamberts (fL). A defined angular field of view for the measuring detector is needed in order to measure luminance so that a small area within a larger uniform field is sampled. This can be accomplished using either steradian tubes or lens systems.
Information for this application can be found under:
Products section: 
