A lighthouse exposure system for more uniformly exposing photosensitive material on a television picture tube face panel. The usual lighthouse problems of (i) over-intense radiation along the face panel parallel to the elongated arc lamp and, (ii) corner-to-corner intensity differential associated with lighthouse light source offset, are both overcome. The intensity contour correcting lenses or shaders (or the like) which are usually disposed between the effective point of light emanation and the face panel are rendered unnecessary. The system employs a light collimator which channels, by means of internal reflection, light from an elongated arc lamp to a collimator tip from which light is then emitted toward the face panel. The surface of the collimator is altered in a predetermined manner so as to interrupt the surface boundary reflection usually occurring therefrom. In a preferred embodiment, the collimator has two frosted areas disposed opposingly and near the tip, with the frosted areas being aligned with the elongated arc lamp.
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