It has been a long time since I last did some phase contrast microscopy with my Zeiss IM35 microscope so here is a quick study of some sediment from the bottom of my pot pond.
Andy
Algae – x10 objective, variety of Phase and illumination settings (all transilluminated – various aperture settings on illuminator and light intensity, and Phase 1/2):
Algae fond pot pond x32 obj x2 Optovar 020819:
Video: