Optical microscopy of biological specimens, particularly live cells, is difficult as they generally lack sufficient contrast to be studied successfully as typically the internal structures of the cell are colorless and transparent. Commonly, contrast is increased by staining the different structures with selective dyes, but this involves killing and fixing the sample. Staining may also introduce artifacts, apparent structural details caused by the processing of the specimen and are thus not a legitimate feature of the specimen. Further, microscopy of different elements of these biological specimens typically requires multiple microscopy techniques on multiple specimens. According to embodiments of the invention simultaneous imaging techniques are applied to a biological specimen such as fluorescent imaging and dark field imaging by designing an experimental evaluation system and associated illumination system addressing the conflicting demands of these approaches.