“Every element of a cross-lined screen acts as a pinhole camera, and reproduces an image of the aperture of the objective in whose rear focal plane it is placed. Thus, when using a square stop, the dots in the halftone produced will be square in shape; and when the stop is triangular, the dots produced will be triangles. If a diaphragm is used with several holes, each element of the screen will reproduce as many dots as there are holes in the diaphragm. If these holes be covered with red, yellow, and blue filters, the three dots will correspond in density to the intensities of the colors entering the lens aperture. In order to convert the negative into its natural colors, it can be converted into a transparency and projected through the three-color diaphragm and the original lens system.”
(Friedman, Joseph Solomon (1945): History of Color Photography. Boston: The American Photographic Publishing Company. p. 225.)
Original Technical Papers and Primary Sources
Ahriman = Liesegang, Raphael Eduard (1896): Von der zukünftigen Photographie. Ein neues Prinzip der Farbenphotographie. In: Photographisches Archiv, 37, pp. 249–251. (In German)
British Journal of Photography, 43, 1896, p. 569. (In German)
Dr. N. (1937): Linsenraster. In: Film-Kurier, 183, 2.8.1937, Serie “Farb-Film-Fibel”. (in German)
Friedman, Joseph Solomon (1945): History of Color Photography. Boston: The American Photographic Publishing Company, p. 225.