Geometrical Optics Curvature centre point surface of the single-leaf hyperboloid Curvature centre point surface of the single-leaf hyperboloid Curvature centre point surface of the triaxial ellipsoid Curvature centre point surface of the triaxial ellipsoid Curvature centre point surface of the triaxial ellipsoid Curvature centre point surface Infinitesimal neighbourhood of a line congruence Infinitesimal neighbourhood of a line congruence Infinitesimal neighbourhood of a line congruence 21 big plaques for the easiest refraction appearances Curvature centre point surface Slide: Camera