Abstract: A multiple pass optical system comprising a reflecting objective placed across the path of a radiant flux emitted by an illuminator; the objective being mounted pivotally around its own axis. Further, the radiant flux its incident upon a compound collective comprised of two different-curvature mirrors arranged at right angles to each other.From the lens of the radiant flux, the flux is directed again to the reflecting lens to be reflected therefrom and upon passing the final cycle in the system, it emerges.

Abstract: A multiple pass optical matrix system comprises two main and one additional objective mirrors arranged on a mount. The mount is mechanically connected with means for rotation of the mount about axes perpendicular and parallel to the image matrix row. The main and auxiliary field mirrors are placed opposite the mount along the longitudinal axis of the system.

Abstract: The multiple reflection optical system includes opposing reflecting members of which one is adjoined by entrance and exit slits and is made up of two identical mirrors defining a group arranged symmetrically with respect to one of the slits. The other reflecting member is made up of two concave mirrors of different dimensions. The spacing between the group of the identical mirrors and the concave mirrors, as well as the focal length of the concave mirror of the smaller dimensions are 1.5 times the focal length of the concave mirror of the greater dimensions.