Abstract: An illuminator for measurement of curved specular surfaces is provided comprising a hemispherical support structure containing single or multiple polygonal groups of directional light sources, whose beams converge at a point underneath the hemisphere containing the area to be inspected. The lights reflect from the curved surfaces vertically through an aperture in the top of the hemisphere to one or more cameras that are part of a machine vision system. In one form of the embodiment, two octagonal groups of LEDs (Light Emitting Diodes) mounted at different elevations on the hemisphere are used. The shapes and patterns of the reflected points of light serve as fiducials for measurement of the positions, radii, surface quality and relative heights of the curved surfaces.