25 form exhibition star arrangement. All freshwater diatoms. Prepared by Klaus Kemp. Mounted in Styrax, dated 1/12/1993. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo NA 0.65 objective. Leitz Heine condenser, set just into dark ground. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 6 images stacked in Zerene (Dmap).