An arrangement of three Nitzschia sigma. ‘Test’ slide. Prepared by Samuel Henry Meakin. Mounted in Sirax and dated April 1943. Olympus BHB microscope using 450nm LED light. 40x Leitz Pl Apo NA 1.00 objective, oil immersion. Olympus Aplanat Achromat condenser, oil immersion, oblique lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. 22 images stacked in Zerene (Pmax). Also shown as an inverted image (because I think it looks nice).