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Journal of the Optical Society of America

Journal of the Optical Society of America

  • Vol. 25, Iss. 1 — Jan. 1, 1935
  • pp: 24–35

A Maxwell Triangle Yielding Uniform Chromaticity Scales

DEANE B. JUDD  »View Author Affiliations

JOSA, Vol. 25, Issue 1, pp. 24-35 (1935)

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A calorimetric coordinate system has been found by trial and error whose Maxwell triangle has the useful property that the length of any line on it is a close measure of the chromaticity difference between the stimuli represented at the extremes of the line. Such accurate chromaticity scales may be derived from this triangle merely by stepping off equal intervals on it that it has been called the “uniform-scale triangle.” The definition of the system is given, and also a comparison of experimental sensibility data with corresponding data derived from the triangle. An important application of this coordinate system is its use in finding from any series of colors the one most resembling a neighboring color of the same brilliance, for example, the finding of the nearest color temperature for a neighboring non-Planckian stimulus.draw the shortest line from the point representing the non-Planckian stimulus to the Planckian locus.

DEANE B. JUDD, "A Maxwell Triangle Yielding Uniform Chromaticity Scales," J. Opt. Soc. Am. 25, 24-35 (1935)

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  1. D. B. Judd, Chromaticity Sensibility to Stimulus Differences, J. Opt. Soc. Am. 22, 72 (1932).
  2. Judd, J. Opt. Soc. Am. 22, 87 (1932).
  3. Proc. 8th Session, International Commission on Illumination, Cambridge, pp. 19–29, September, 1931. D. B Judd, The 1931 I. C. I. Standard Observer and Coordinate System for Colorimetry, J. Opt. Soc. Am. 23, 359 (1933). T. Smith and J. Guild, The C. I. E. Colorimetric Standards and Their Use, Trans. Opt. Soc. 33, 73 (1931–32).
  4. Judd, J. Opt. Soc. Am. 22, 102 (1932).
  5. I. G. Priest, A Precision Method for Producing Artificial Daylight, Phys. Rev. 11, 502 (1918); J. Opt. Soc. Am. and Rev. Sci. Inst. 12, 479 (1926). D. B. Judd, Reduction of Data on Mixture of Color Stimuli, Bur. Standards J. Research 4, 525 (1930); RP163.
  6. R. Davis and K. S. Gibson, Filters for the Reproduction of Sunlight and Daylight and the Determination of Color Temperature, Misc. Pub. Bur. Stand. 114, 16 (1931).
  7. Reference 6, Table I.
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  11. Wright and Pitt, Proc. Phys. Soc. 46, 466 (1934).
  12. D. B. Judd, A General Formula for the Computation of Colorimetric Purity, J. Opt. Soc. Am. 21, 729 (1931); see Eq. (14).
  13. E. P. T. Tyndall, Chromaticity Sensibility to Wave Length Difference as a Function of Purity, J. Opt. Soc. Am. 23, 15 (1933).
  14. W. Watson, Note on the Sensibility of the Eye to Variations of Wave Length, Proc. Roy. Soc. B84, 118 (1911).
  15. F. Donath, Die funktionale Abhängigkeit zwischen Reiz und Empfindung bei der Farbensättigung, Neue Psych. Stud. 2, 143 (1926).
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  17. L. C. Martin, F. L. Warburton and W. J. Morgan, Determination of the Sensitiveness of the Eye to Differences in the Saturation of Colours, Medical Research Council, Reports of the Committee upon the Physiology of Vision, XIII, Special Report Series, No. 188, London, 1933.
  18. P. G. Nutting, The Retinal Sensibilities Related to Illuminating Engineering, Trans. Illum. Eng. Soc. 11, 16 (1916).
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  20. Judd, J. Opt. Soc. Am. 22, 95 (1932); see also footnote 17.
  21. D. B. Judd, Saturation Scalefor Yellow Colors, J. Opt. Soc. Am. 23, 35 (1933).
  22. I. G. Priest and F. G. Brickwedde, The Minimum Perceptible Colorimetric Purity as a Function of Dominant Wave Length with Sunlight as Neutral Standard, J. Opt. Soc. Am. and Rev. Sci. Inst. 13, 306 (1926); see also footnote 1.
  23. D. McL. Purdy, On the Saturations and Chromatic Thresholds of the Spectral Colours, Brit. J. Psych. (Gen. Sec.) 21 (Part 3), 283 (1931).
  24. K. S. Gibson and E. P. T. Tyndall, Visibility of Radiant Energy, Bur. Stand. Sci. Pap. 19, 131 (1923–24); S475. See first column of their Table III, p. 174.
  25. D. B. Judd, Sensibility to Color-Temperature Change as a Function of Temperature, J. Opt. Soc. Am. 23, 7 (1933).
  26. I. G. Priest, A Proposed Scale for Use in Specifying the Chromaticity of Icandescent Illuminants and Various Phases of Daylight, J. Opt. Soc. Am. 23, 41 (1933).
  27. I. G. Priest and K. S. Gibson, Standardising the Red and Yellow Lovibond Glasses, J. Opt. Soc. Am. and Rev. Sci. Inst. 16, 116 (1928).
  28. Judd, J. Opt. Soc. Am. 23, 35 (1933).
  29. K. S. Gibson and G. W. Haupt, Standardization of Lovibond Red Glasses in Combination with Lovibond 35 Yellow, Bur. Standards J. Research, 13, 433 (1934), RP718.
  30. Judd, J. Opt. Soc. Am. 22, 98 (1932).
  31. J. Opt. Soc. Am. 23, 35 (1933).
  32. E. Sclrödinger, Grundlinien einer Theorie der Farbenmetrik im Tagessehen, Ann. d. Physik (4), 63, 481 (1920); Die Gesichtsempfindungen, Müller-Pouillets Lehrbuch der Physik, 2nd Ed. 2, 456 (1926).
  33. Selig Hecht, The Interrelation of Various Aspects of Color Vision, J. Opt. Soc. Am. 21, 615 (1931).
  34. G. E. Müiller, Über die Farbenempfindungen, Leipzig: Barth, 1930.
  35. I. G. Priest, The Complete Scale of Color Temperature …, Phys. Rev. 20, 93 (1922); The Colorimetry and Photometry of Daylight and Incandescent Illuminants …, J. Opt. Soc. Am. and Rev. Sci. Inst. 7, 1175 (1923).
  36. Report of Color Committee of the American Oil Chemists' Society, Year 1932–1933, Oil and Soap 10, 114 (1933).
  37. In this instrument no provision at all is made for equalizing the brightnesses of the two fields; hence, the problem, strictly a tridimensional one, is reduced to a single specification by neglecting both small chromaticity and small brilliance differences.
  38. R. Davis, A Correlated Color Temperature for Illuminants, Bur. Standards J. Research 7, 659 (1931); RP365.
  39. Note distinction from x¯ and y¯ of relation (3).

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