The American annual of photography . cause of its frequent usage every color operator will in-stantly recognize this diagram and will also at the same timerecognize its utter falsity in so far as his actual workingresults are concerned. In this modern age, and at the present stage of the knowl-edge of tri-color, there is really no legitimate excuse for thepublication of this diagram, which conveys an entirely mis-leading conception. To take up this point in detail, we find that if an operatortacks up with the copy, three soHd patches of his tri-colorinks, that generally—the result through the
The American annual of photography . cause of its frequent usage every color operator will in-stantly recognize this diagram and will also at the same timerecognize its utter falsity in so far as his actual workingresults are concerned. In this modern age, and at the present stage of the knowl-edge of tri-color, there is really no legitimate excuse for thepublication of this diagram, which conveys an entirely mis-leading conception. To take up this point in detail, we find that if an operatortacks up with the copy, three soHd patches of his tri-colorinks, that generally—the result through the red filter is prac-tically a solid yellow and three-quarter tone red. Throughthe green filter the yellow is rendered practically as a solid,but the blue is nearly as transparent on the negative as is thered; while the result through the blue-violet filter is that theblue is about half (or quarter) tone; red the same, and prac-tically transparent yellow. This is shown in Fig. 2. 272 Blue Yellow Red Blue filterGreen filterRed filter. Yellow printRed printBlue print Fig. 2 Of course the operator getting this result in almost everycase blames the filters, and casts about for some change intheir dye constitution which will achieve the happy effectshown in the diagram of theoretical action, but with the re-sult that while such change will perhaps show improvementon some one color, yet it is at the expense of some other. Then,of course, he blames the plates. If we, however, give consideration to the matter, this dis-crepancy in results is easily explainable. To begin with the filters, it has been determined definitely byindependent authoritative workers, that the best results areto be obtained if the red sensation negative be acted uponby light extending from the extreme red end of the spec-trum to wave-length 5900; the green from wave-length 6000to 4900, and the blue-violet from 5000 to 4000, and that thefilters should present sharp and abrupt absorptions. It doesnot make any diffe
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishernewyorktennantandw
