angle u03b1 amounts to values between 0 5 u00b0 and 10 u00b0 each of these stereoscopic imaging beam paths ba bb image the focal plane 6 of the objective system 2 and an object disposable in the object plane 6 e g an eye 61 into a two dimensional intermediate image p in a magnifying way so that when observing both imaging beam paths ba bb a magnified three dimensional image perception can be obtained in the embodiment shown the objective system 2 is configured having two elements and includes two optical lenses 21 22 being traversed one after another by the stereoscopic imaging beam paths ba bb the stereoscopic imaging beam paths ba bb are guided in common optical lenses 21 22 the distance between the optical lenses 21 22 is variable along their common optical axis a in order vary a position of the focal plane 6 of the objective system 2 in the embodiment shown the working distance of the objective system 2 may amount to a value between 150 mm and 200 mm the working distance is the distance of the focal plane 6 to the front lens vertex of the optical lens 21 of the objective system 2 along the stereoscopic imaging beam paths ba.