Abstract: A defocusable electro-optical system for scanning the near-specular surface of an object to be examined with a light beam to produce a reflected-light pattern that depends on the relative reflectivity of the different components which make up the surface. The system includes a light source producing an illumination beam that is directed by a scanning mechanism through an objective which focuses the beam onto the surface to be examined. The beam reflected from the surface is directed toward a photodetector through a field stop that defines the size of the viewed area when the object surface lies in the focal plane. The viewed object surface is illuminated in a manner imaging thereon an image of the light source comparable in size to the field stop, so that when the object surface lies in the focal plane the light source image is coincident therewith.