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 217
close from the centre, give admirable definition since they act for part of the time like a small stop ; at the same time they are fixtures and cannot be used for other lenses, and they admit more light to the centre of the picture than the sky and fore- ground. Unfortunately, they cannot be fitted… … Fig. 143. — Perken’s Iris Pig. 144. — Compound Shutter. Sector Shutter. cross one another at this spot, and the shutter therefore has the least possible distance to travel. Among those of which I have had personal experience and can thoroughly recommend are Bausch & Lomb’s Unicum, Automat, and…
Photographic optics · Color photography
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