Immersion apparatus and method for dynamically adapting a medium to a specimen

An arrangement and method for supplying immersion media and a method for setting optical parameters of a medium, includes a media supply unit for the controlled supply of a medium or of a mixture into a contact region between an optical lens and a specimen slide, on which a specimen may be arranged. An image capture unit is provided for capturing image data on the basis of detection radiation from the object space along a detection beam path extending through the contact region. An evaluation unit is provided to establish current image parameters on the basis of captured image data, to compare said current image parameters to intended image parameters and to establish a desired mixing ratio of at least two components of the medium depending on the comparison. A mixing apparatus for the controlled setting of the mixing ratio of the components of the medium to be introduced into the contact region and a control unit for actuating the mixing apparatus depending on the established desired mixing ratio are parts of the arrangement.