Stauroneis phoenicenteron test diatom strew slide by Brunel. Mounted in Pleurax. Olympus BHB microscope using 450nm LED light. 60x Olympus Splan Apo NA 1.40 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. Olympus 2.5x NFK Photoeyepiece. Monochrome converted Nikon d800 camera. 7 images stacked in Zerene (Pmax).