A microscope (10) includes an objective system (30) and a zoom system (32). The microscope (10) furthermore has a manually rotatable rotary wheel (108) for adjusting the magnification of the zoom system (32), the rotary wheel (108) being rotatable within a predetermined maximum rotation range. The rotary wheel (108) includes a first engagement element (162, 164). In addition, at least one second engagement element (130 to 136) is movably mounted on a housing (100) of the microscope (10). This second engagement element (130 to 136) is movable between a deactivated and an activated position, being in engagement with the first engagement element (162, 164) in an activated position. The position of the second engagement element (130 to 136) is determined by the respective objective (44, 52) currently received in the beam path.