A method of manufacturing an optical system comprises assembling an
optical element on a mounting frame thereof. The mounting frame is
disposed on a rotary table having an axis of rotation, and the mounting
frame is adjusted such that a predefined axis of symmetry thereof is
parallel to the axis of rotation. The optical element is placed on the
mounting frame, and an interferometric measurement of a surface of the
optical element is performed. The interferometric measurement is analyzed
to arrange the optical element relative to the mounting frame such that a
predefined axis of the optical element is parallel to the axis of
rotation.