Handbook of the practice and art of photography (1875)
Vogel, Hermann Wilhelm, 1834-1898, Molling, Edward F · Philadelphia, Benerman & Wilson · leaf 75
o artistically perfect pictures could be made is self-evident, and it became soon necessary for portrait pho- tographers to have a lens that would work with a large opening, and hence have a large amount of light. The invention of such a lens by Petzval, in Vienna, in the year 1841, was an event in… … the first lens according to Petzval's directions, and Martin, in Vienna, took the first daguerreotype with short exposure. This Portrait lens is a double objective with central stop and two unequal lenses. The front lens, A (Fig. 46), consists of a biconvex crown, and an almost plano-convex…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
