Photography with emulsions: a treatise on the theory and practical working of gelatine and collodion emulsion processes (1882)
Abney, William de Wiveleslie, Sir, 1843-1920 · New York, Scovill manufacturing co. · leaf 270
which to examine negatives or positives after fixing, enabling the operator to judge of their quality, thereby avoid- ing the necessity of leaving the dark room in search of white light. 5. A clear, transparent light for making positives on glass (gelatino- bromide). This feature is a valuable one.… … Lantern arranged for developing and, after fixing, examining negatives by opal light. 7. The making of photo-micrographs with the clear, transparent light, which can readily be accomplished with the gelatino-bromide plate and the microscope. 8. By the adjustment of condensers and holder for slides,…
Photography
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