Abstract: A test device for setting motor-vehicle headlight beams is described, which essentially consists of a base plate (1) and the two open-up parts, namely the lens holder (2) and the test surface (3). The lens holder contains an aspheric lens (4) of which the optical axis (5) is parallel to the rest surface (6) of the base plate (1) and simultaneously perpendicular to the test surface when the device is in the opened-up, operational position. The lens is of such height and so corrected that the light of headlights mounted low, normally or high is passed without headlight elevation adjustment and is imaged on the test surface located approximately in the lens focus, and in that the test result is entirely independent of the particular headlight elevation.

Abstract: An optical sighting device for firearms, more particularly hand guns and the like, geodesic instruments and the like comprising a telescope-type optical system with an objective and an ocular, or eyepiece, element and provided with a target mark, such as a reticle, positioned within the optical system, which is projected onto infinity, such as to be seen in the same plane as the plane of viewing of the target. The optical system consists of a massive cylindrical lens body of transparent material which has its opposite end surfaces formed as optically effective surfaces of symmetrical curvature, the surface of the objective being convex for converging the parallel light rays emitted from the target, and the surface of the ocular being concave for re-aligning the transmitted light rays to a beam of parallel rays.

Abstract: An illumination unit for microfilm viewers, and more particularly for microfilm viewers of the binocular-microscope type, providing illumination of the microfilm by a light source disposed either on the outside of the viewer or incorporated in the viewer, such that operation of the viewer does not depend on an outside source of light energy or electrical energy.

Abstract: A binocular optical apparatus provided with an objective and eyepiece lens system and using a mirror system for deflecting a light beam from the illuminated object to the eyepieces. The interocular separation, or distance between the eyepieces is adjustable by way of making the optical axis of at least one eyepiece swivelable relative to the optical axis of the other eyepiece at an angle determining the interocular distance of the eyepieces within an angle conforming to the range of natural eye movement such as to avoid eye strain. One of the mirrors of the mirror system is angularly movable at half the angle of motion of the movable eyepiece during adjustment to an appropriate interocular distance, by means of a lever drive arrangement, such that the image projected by the mirror into the eyepiece plane remains stable during adjustment of the interocular distance. The invention has particular applications for microfilm binocular viewers having a high magnification rate.