The device, which can be used in particular in a sighting device, successively comprises a mirror parabolode 10 and a mirror hyperbolode 12. One of the foci of the mirror hyperbolode coincides with the focus of the mirror parabolode. The reflecting surfaces of the mirrors are formed by portions out of the axis of the corresponding tie-lines and have dimensions of the same order of magnitude. The parabolode is placed in such a way that an incident beam of rays means parallel to its axis has an angle of incidence on the mirror parabolode such as the mirror hyperbolode does not distort the incident beam. The radii of curvature of the two mirrors on their axis, do not differ by more than 10%).
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