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Incoming links: Darkfield Illumination by Nikon Instruments Inc.
Dark-field microscopy Created 2026-10-18 Updated 2026-11-05
Dark-field microscopy excludes directly transmitted illumination from the microscope objective, while admitting light scattered by the specimen. A transparent particle can then appear bright against a dark background even when it has little optical absorption.
One implementation illuminates the specimen with a hollow cone whose direct rays pass outside the objective's acceptance cone. Scattering of light at particles or edges redirects some of this illumination into the objective. Dust and scratches also become bright, so a clean blank specimen is a useful control.[ref]
Darkfield Illumination by Nikon Instruments Inc.. Illumination geometry and discussion of light scattered into the objective
Detection is not the same as optical resolution: a very small particle may be visible as an unresolved spot whose width is set by the point spread function.