The Sciopticon manual : explaining lantern projections in general, and the Sciopticon apparatus in particular, including magic lantern attachments, experiments, novelties, colored and photo-transparencies, mechanical movements, etc. (1877)
Marcy, L. J. (Lorenzo J.) · Philadelphia : J.A. Moore · leaf 31
otography a person had to sit in front of such a lens, in a strong light, for several minutes. That in this way no artistically perfect pictures could be made is self-evident, and so it became necessary for portrait photographers to have a lens that would work satisfactorily with a larger opening.… … Mg. 13. The front lens A consists of a biconvex crown, and an almost plano-concave flint-glass lens, eemented to- gether with Canada balsam. The back lens B consists
Lantern projection · Slides (Photography)
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
