Optical chart NUMBER 836 illustrates the focal length required to capture different angles on photographic plates in war industries. Example No. 8 demonstrates that a diagonal of an 11x14 plate requires a focal length of 9 inches. The chart provides focal lengths for various plate sizes, ranging from 4x5 to 20x24 inches.

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Size: 9182px × 6304px
Photo credit: © piemags/NSC / Alamy / Afripics
License: Licensed
Model Released: No

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