Abstract: This invention relates to an optical apparatus for and a method of recording or instantaneously visualizing enlarged stereoscopic images of objects.The apparatus comprises a stationary stopped down lens (1, 4) providing an enlarged image of an object (2), a first lenticular grating (3), the elementary lenses of which are positioned in the vicinity of said enlarged image, the angle of field of the lenticular grating (3) is substantially equal to the aperture angle (4') of the exit pupil of the lens viewed from the lenticular grating (3), in order to provide an instantaneous, composite, sampled image at the level of the focal plane of the first lenticular grating.According to one embodiment for instantaneous observation, the apparatus also comprises a relief reversing system (9), an observation system (10) and a beam expanding system (11).