A beam splitter device (1) for a microscope (2), and for a microscope imaging method, supports at least two beamsplitting surfaces (4, 14). The two beamsplitting surfaces (4, 14) have different reflection-to-transmission ratios. The beam splitter device (1) has an optical path (3, 3a, 3b). A first one of the two beamsplitting surfaces (4, 14) is configured to be moved from a first operation position (15), in which the first beamsplitting surface (4) is located in the optical path, to a second operation position (16), in which a second (14) of the beamsplitting surfaces (4, 14) is located in the optical path. With this configuration, it is possible to change the available light in the branches (3a, 3b) of the optical path (3) after the beamsplitting surface (4, 14). This is useful if one of the branches (3a, 3b) is directed to an exit port (8) configured to receive a camera. By directing more light to the camera exit port (8), the image quality of the camera is improved.