is used as the light source for the transmitted light bright field illumination and a shutter is activated at a location in the illumination beam path of the transmitted light bright field illumination during incident light fluorescence illumination and this shutter is deactivated during transmitted light bright field illumination application_number US 201213558548 A description the sole fig1 is a schematic view of a configuration of a microscope 1 according to the invention along with the main components thereof the microscope system 1 being designed for analysis of a sample 10 in incident light fluorescence illumination and in transmitted light bright field illumination the two types of illumination usually being alternated the incident light fluorescence illumination means 2 comprises the following components an incident light illumination light source 17 for example a mercury vapour lamp and a fluorescence filter block 12 which are arranged on the incident light illumination axis 16 the fluorescence filter block 12 comprises an excitation filter 14 which is followed in the propagation direction of the incident light illumination light by a beam splitter 13 the excitation filter 14 is used to select one or more wavelength ranges which are suitable for exciting fluorescences in the sample 10 the beam splitter 13 deflects the excitation light which is.