Wilson's quarter century in photography : a collection of hints on practical photography which form a complete text-book of the art (1887)
Wilson, Edward L. (Edward Livingston), 1838-1903 · New York : E.L. Wilson · leaf 65
tion is barrel-shaped; but by placing the diaphragm behind the lens (as in Fig. 46) the dis- tortion is of the opposite nature — that is, pincushion-shaped. Rays coming from D (Fig. 45) pass through the upper part of the lens, while in the latter, through the lower part. Now you will readily see… … so that by proper combination of lenses of suitable curves any material distortion can nearly be overcome upon a limited field.
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
