The prior patent referred to above discloses two specific embodiments, one of them with a varifocal ratio f.sub.max /f.sub.min approximately equal to 8, the other with a varifocal ratio of about 10.  In the wide-angle position of the objective, its relative aperture is 1:1.2 according to the first embodiment and 1:1.8 according to the second one; the first system, accordingly, falls in the so-called XL (=existing light) class permitting--in a cinematographic camera--the taking of indoor motion pictures without additional illumination.  The effective area of the third (negative) component of an objective as described in that patent is restricted to provide full illumination of the fourth (positive) component by axially incident light rays in the wide-angle position but less than full illumination in the telephoto position, thereby enabling a reduction in the lens diameters of the front component.