Methods, systems and computer program products are disclosed for displaying a preview of pixels to be effected by a brush tip area. With the microscope according to the present invention and the method according to the invention for operating a microscope, drift-related changes can be detected and compensated for. The reference detector is read multiple times during the frame period in which the image sensor array captures a scene to detect illuminant intensities during the same frame period. An output port of the dummy waveguide is arranged on the same surface. Each gain can be adjusted separately to product a large range of linearization characteristics. Medial and lateral tendons are located between and correspond to profiles of the plurality of the anterior and posterior projections such that the medial and lateral tendons are located on opposed sides of the liner body relative to one another.