stop

A stop that is placed in an image or aperture plane to control the diameter of the field of view or the numerical aperture, respectively. It may be an iris diaphragm.

Synonyms: diaphragm

See also: iris diaphragm, field stop, aperture stop, illuminated field stop, illuminating aperture stop

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The Microscope Optical Train

The optical train consists of an illuminator, condenser, specimen, objective, and detector.