The C-BD Diascopic Brightfield/Darkfield stand introduced with
the Nikon SMZ1500 uses a seven-sided toroidal mirror to
substantially reduce stray light. Use this interactive Flash
tutorial to explore how mirror shape affects the amount of light
entering the objective in darkfield stereoscopic microscopy. To
operate the tutorial, use the slider bar to morph the mirror
assembly between a standard cylindrical reflection mirror and
the new Nikon toroidal mirror. Stray light reflected from the
cylindrical mirror ordinarily causes a decrease in contrast when
using short-working distance objectives under darkfield
diascopic illumination, because a considerable amount of light
enters the objective front lens. When using a toroidal mirror,
direct light is shielded from entering the objective. Brian O.
Flynn and Michael W. Davidson - National High Magnetic Field
Laboratory, 1800 East Paul Dirac Dr., The Florida State
University, Tallahassee, Florida, 32310.