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VARIABLE DARK‐GROUND ILLUMINATION
Author(s) -
Hartley W. G.
Publication year - 1950
Publication title -
journal of the royal microscopical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0368-3974
DOI - 10.1111/j.1365-2818.1950.tb04436.x
Subject(s) - paraboloid , analyser , optics , dark field microscopy , polarization (electrochemistry) , physics , mathematics , geometry , chemistry , microscopy , surface (topology)
SYNOPSIS. By exploiting the property of polarization, the intensity of the light directly entering an objective can be controlled, so that the illumination of the specimen may be adjusted between critical bright and dark field conditions. The use of a suitable Polaroid substage stop in conjunction with an analyser is described, discussed, and also the conversion of an immersion paraboloid to this use. Bn &‐focal illuminating system of 0.86 N.A., suitable for this and a variety of other uses, is also described