Abstract: An apparatus for applying a laser beam to an area on a work surface includes means for viewing said area with visible light prior and subsequent to application of the laser beam. The laser beam system includes a stationary portion comprising a laser, condenser and pinhole and a movable portion comprising a large aperture objective. The visible light system comprises a fixed video camera and lens and a movable portion including an objective and a light source. The movable portions of the laser beam system and the visible light system are mounted on a common slidable carriage.

Abstract: The invention provides a highly corrected, parfocalized, two-focal-length optical system comprising a primary image producing group consisting of a catadioptric lens system which forms its image within a first, positive field lens, and a second group comprising a symmetrical relay system coaxial with the primary group and movable axially relative to the primary image producing group, the relay system reimaging the image formed by the primary group through a second, negative field lens onto the fixed plane of the final image, movement of the relay lens between its extreme positions permitting close focusing of the entire system without altering its overall length.

Abstract: The invention provides a highly corrected catadioptric telephoto lens comprising in succession, from the long conjugate end, an aspherized negative meniscus corrector plate, a Mangin type primary mirror which directs light to a secondary mirror comprising the central portion of the second surface of the corrector lens, a first positive meniscus corrector lens and a second biconcave corrector lens. The relative aperture is f/8 and the overall length of the system from first vertex to image plane is less than 0.4 focal length.