An 8 form diatom slide mounted in Styrax. Labelled as Watson and Sons Ltd. Olympus BHB microscope using 450nm LED light. 20x Nikon Plan Apo NA 0.65 objective. Olympus Aplanat Achromat condenser, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 31 images stacked in Zerene (Pmax). It was a nice clear mountant, although it has yellowed slightly.