Motion Picture News (Sept-Oct 1916)

2578 ACCESSORY NEWS SECTION Vol. 14. No. 16 The Camera Color Photography Early Attempts to Reproduce Colors by Photography — The Work of Seebeck, Niepce, Herschel, Becquerel and Poitevin — Ducos du Haiiron a Pioneer Investigator — Lippman's Interference Process MAXWELL'S COLOR SENSATION CURVES Through an error the diagram of the Maxiuell curves — referred to as Fig. p in last week's installment of " Color Photography " — was omitted. We present Fig. g herewith for our readers to study in conjunction with the subject matter in the previous issue of the Camera Department, and desire to emphasize the fact that the Maxwell Color Sensation Curves must be taken into consideration when preparing the filters used in photographing or projecting film pictures in natural colors. WITH the fundamental principles of light and color and their characteristic actions in the photographic processes established, we will next consider the various attempts which have been made to record colors photographically, commenting as we go along on the competency of the various methods when applied to cinematography. In reviewing the history of color photography, we find that many of the historic pioneers of ordinary photography also gave consideration to the photographic reproduction of color. Seebeck's Experiments with Silver Chloride The earliest investigator whose results have been recorded in detail was T. J. Seebeck of Jena, Germany, who in 1810 endeavored to reproduce the colors of the solar spectrum cast by a prism upon paper coated with silver subchloride. Seebeck was successful in reproducing some colors, the red recording upon his chloride coated paper, the green being absent, and the violet region of the spectrum appearing brown and blue. Goethe in his " Farbenlehre " gives a full account of Seebeck's experiments, which were not without their significance as was proven by later investigations. J. Nicephore Niepce, a Frencliman and the discoverer of the Bitumen process of photography (which is one of the earliest photographic processes) observed color effects in 1829 in some of his early photographs made on glass and metal plates coated with a thin film of Bitumen (Syrian asphalt). These findings of Niepce were not made known, however, until after he formed his partnership with Daguerre, many years later. In 1840 Sir John Herschel, a noted English philosopher, de scribed the spectrum colors he had obtained on silver chloride paper in a communication to the Royal Society. Herschel at that time predicted future advances in color photography. Becquerel's Results on Silver Plates Better results than any of the preceding investigators were secured, however, by a French scientist, Edmund Becquerel in 1848. Becquerel also sought to record the colors of the spectrum, but his methods differed from those of his predecessors. He used silver plates which he chlorinized by plunging them into chlorine water. He later prepared his plates by connecting them to the copper pole of a galvanic battery and immersing them in hydrochloric acid. In this way he was able to secure a coating of any desired thickness. Becquerel's plates gave a good rendition of all colors except the green, which was rather poorly recorded. Experiments with chlorinized silver plates (similar to Becquerel's) were commenced in 1841 by Niepce de St. Victor (a nephew of Nicephore Niepce) who exhibited some specimens of natural color photography in Paris some years later. It should be noted here that all of these color effects produced on surfaces coated with silver chloride were secured after the chloride had been previously darkened by exposure to light. It is hardly necessary to state that the colors so recorded were in no instance permanent, disappearing finally on continued exposure to light. Alphonse Louis Poitevin, another French worker, finally succeeded in fixing (rendering permanent) these colored images by the use of sulphuric acid. Maxwell's Researches In order to maintain our historical continuity we should not fail to here mention that Clerk-Maxwell in England published his researches on color vision, and the Maxwell Color Sensation curves, in the year 1861. Captain (now Sir William) Abney, to whom we are indebted for many valuable works and communica (Continued on page 2583) I