The science and practice of photography : an elementary textbook on the scientific theory and a laboratory manual (1920)
Roebuck, John R. (John Ransom), 1876-1965 · New York ; London : D. Appleton and company · leaf 193
lenses 163 glass. Poor polish of the surfaces and bubbles in the glass also increase the loss. 104. The remaining difficulty is that of unequal illumination, and Fig. 40 will show some of the reasons for it. The width of the pencil of light going to different parts of the plate is cut down by … the lens barrel when it makes an angle with the axis. For this reason, lenses which are made to cover a large plate as compared with their focal lengths, that is, lenses taking in a big angle of view, are made with the lens barrel as short as possible. Even in case the beam is not cut down by the…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
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