A microscope (10) is described, having an aperture limiter (12), arranged in the beam path (22), for generating at least one optical channel (16; 18; 20). The aperture limiter (12) is embodied to set the aperture of the at least one optical channel (16; 18; 20). The aperture limiter (12) is furthermore embodied in such a way that in a first operating mode a first optical channel, and in a second operating mode at least one second optical channel, is selectively generable. The aperture limiter is also arranged in the pupil plane of the beam path.