Modern chromatics, with applications to art and industry (1879)
Rood, Ogden N. (Ogden Nicholas), 1831-1902 · New York, D. Appleton and Company · leaf 211
ch divides ordinary light up into two beams of equal intensity. In this latter case we arrange a disk by making half of its surface white, the other half black, as represented in Fig. 89 ; alongside of it, on a black ground, we place a strip of the same white pa- per ; the disk is then set in… … 90.— Appearance of Disk in Eota- Strip for Photometric Comparison. tion. the Strip being viewed through a Calc-Spar Prism. original strip ; but either of these images will be as bright as the grey disk, showing that the luminosity of the grey disk is just one half of that of the white. This gives…
Color · Painting · Color in art
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
