Photographic optics and colour photography : including the camera, kinematograph, optical lantern, and the theory and practice of image formation (1909)
Johnson, G. Lindsay (George Lindsay), 1853-1943 · New York : D. Van Nostrand Co. · leaf 180
to use a flap- shutter attached to the lens mount, and hinging aboye it. This can be lifted up and allowed to drop by a pneumatic ball, so that any ratio of exposure one pleases can be given to the fore- ground and sky respectively (Fig. 112). Busch makes an excellent pneumatic shutter (“ Sky shade… … Fig. 112. — Flap form of Skyshade Fig. 111. Shutter. in ortochrome work, as without some such screen the skies are invariably spoilt through over exposure. 3. For the purpose of reducing Aberrations and thereby limiting the Size of the Circles of Confusion. — This was of far more importance in the…
Photographic optics · Color photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
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