An experimental investigation is reported of a magnetooptical readout system for cylindrical magnetic domains in a birefringent orthoferrite crystal. The way in which the magnetooptical readout signal depends on the crystal thickness is investigated in two readout arrangements. Experimental characteristics are given which show the change in the signal and noise components as functions of the angle of rotation of the analyzer. The range of analyzer angles which ensures maximum signal-to-noise ratio is determined.