A matrix [<i>M</i>] is derived for a system of plane first-surface mirrors which transforms a point or the direction cosines of a ray in the image space to the object space. If the general displacement of the mirror system is represented by the screw matrix [<i>S</i>], then the new position of a point image is given by the transformation [<i>S</i>][<i>M</i>][<i>S</i>]<sup>-l</sup>. This method facilitates designing the mirror supporting structure for minimum image shift due to structural deflections.
JOSEPH STILES BEGGS, "Mirror-Image Kinematics," J. Opt. Soc. Am. 50, 388-393 (1960)