Bromide paper : instructions for contact printing and enlarging (1896)
Just, E. A · Bradford : P. Lund, Humphries · leaf 26
direct illumination from the light would be about 6, and the amount from the reflecStor about 94. The law that the intensity decreases in proportion to the square of the distance, would only affe(5t the small share of light (6) coming diredfly from the illuminant source, and therefore by altering… … Fig. 4. The second law that the intensity of the illumination of a plane is in proportion to the cosine of the angle of incidence of the rays of light, would be followed by both the diredl and the refleifted light. Consequently, with the above methods, angles of inclination of the whole surface of…
Photography
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
