detail, but Figs. 1 and 2 are shown to illustrate the nature and extent of the work.
Figure 1 shows the working plot for RP 3/6. It includes the diffuse-normal, König-Martens spectrophotometric data, with some check points; the 45°-normal Martens photometer (with filters) data; the 45°-normal photographic data, 370 to 460 mμ, showing the absorption from the ZnO below 400 mμ; the plotting to a 10-times scale of values below 0.10; and the smooth curves drawn through the diffusenormal and the 45°-normal data. The final judgment as to the true course of all of the curves (representing the adopted values) was made by the senior author of the present paper.
Table IV. Trichromatic analysis of Munsell Atlas colors, 1926 data, 45° illumination. Values computed from spectrophotometric data given in Bureau of Standards Test Report 46,045 on the basis of the I.C.I. standard observer and coordinate system and for I.C.I. Illuminant C.
| Munsell Notation |
Tristimulus Specifcations |
Trichromatic Coefficients |
Dominant Wave-Length* | Excitation Purity* | ||||
| X | Y | Z | x | y | Λ | |||
| R | 8/4 | 0.6807 | 0.6318 | 0.6419 | 0.3483 | 0.3233 | 599 | 12.1 |
| 7/6 | .5399 | .4598 | .4122 | .3824 | .3256 | 603 | 22. | |
| 6/8 | .4406 | .3430 | .2697 | .4183 | .3256 | 606 | 31.5 | |
| 5/10 | .3224 | .2114 | .1277 | .4874 | .3195 | 614 | 48.2 | |
| 4/10 | .2536 | .1557 | .0844 | .5138 | .3153 | 617 | 54.1 | |
| 3/7 | .1215 | .0841 | .0552 | .4659 | .3225 | 612 | 43.2 | |
| 2/4 | .0518 | .0420 | .0385 | .3914 | .3175 | 615 | 22.0 | |
| YR | 8/5 | .6345 | .6059 | .4038 | .3859 | .3685 | 582.8 | 34.1 |
| 7/7 | .5026 | .4616 | .2480 | .4146 | .3808 | 584.5 | 45.2 | |
| 6/8 | .4478 | .3787 | .0973 | .4848 | .4099 | 586.3 | 71.8 | |
| 5/7 | .2666 | .2273 | .0880 | .4581 | .3906 | 587.2 | 59.8 | |
| 4/5 | .1956 | .1652 | .0660 | .4582 | .3871 | 587.8 | 58.8 | |
| 3/4 | .1002 | .0920 | .0578 | .4009 | .3680 | 585.8 | 38.0 | |
| 2/1 | .0496 | .0484 | .0466 | .3434 | .3345 | 586.2 | 13.8 | |
| Y | 8/9 | .5514 | .5833 | .1199 | .4395 | .4649 | 575.7 | 74.4 |
| 7/8 | .4678 | .4898 | .1067 | .4396 | .4602 | 576.2 | 73.4 | |
| 6/7 | .3524 | .3673 | .1000 | .4299 | .4481 | 576.3 | 67.5 | |
| 5/7 | .2329 | .2408 | .0807 | .4201 | .4343 | 576.6 | 61.2 | |
| 4/5 | .1681 | .1688 | .0612 | .4223 | .4240 | 578.2 | 59.2 | |
| 3/3 | .0919 | .0947 | .0590 | .3742 | .3857 | 576.5 | 35.9 | |
| 2/1 | .0519 | .0532 | .0492 | .3365 | .3446 | 576.5 | 14.7 | |
| GY | 8/6 | .5060 | .5953 | .3018 | .3606 | .4243 | 567.8 | 42.6 |
| 7/7 | .4010 | .4952 | .1750 | .3743 | .4623 | 567.1 | 56.5 | |
| 6/8 | .3260 | .4111 | .1424 | .3707 | .4674 | 566.1 | 57.0 | |
| 5/6 | .1615 | .1929 | .0991 | .3562 | .4253 | 566.6 | 41.8 | |
| 4/5 | .1519 | .1887 | .0767 | .3640 | .4521 | 566.0 | 51.0 | |
| 3/3 | .0868 | .0982 | .0666 | .3449 | .3902 | 567.8 | 29.2 | |
| 2/1 | .0444 | .0468 | .0450 | .3260 | .3435 | 570.8 | 11.5 | |
| G | 8/5 | .5395 | .6179 | .5985 | .3072 | .3519 | 546 | 9.0 |
| 7/7 | .4129 | .5181 | .4600 | .2968 | .3725 | 536 | 12.2 | |
| 6/7 | .3067 | .4082 | .3218 | .2959 | .3938 | 534 | 17.7 | |
| 5/7 | .1782 | .2862 | .2080 | .2650 | .4256 | 523 | 21.2 | |
| 4/7 | .1261 | .1944 | .1428 | .2722 | .4195 | 526 | 20.3 | |
| 3/4 | .0748 | .0900 | .0902 | .2934 | .3529 | 520 | 7.2 | |
| 2/1 | .0424 | .0459 | .0473 | .3128 | .3385 | 556 | 6.8 | |
| BG | 8/3 | .5594 | .6229 | .6971 | .2977 | .3314 | 507 | 4.1 |
| 7/5 | .4476 | .5213 | .5939 | .2864 | .3356 | 500 | 7.8 | |
| 6/5 | .3489 | .4343 | .5531 | .2611 | .3250 | 493 | 17.8 | |
| 5/5 | .2003 | .2603 | .3058 | .2613 | .3396 | 497 | 16.4 | |
| 4/5 | .1272 | .1748 | .2637 | .2249 | .3089 | 490 | 32.2 | |
| 3/4 | .0696 | .0823 | .1382 | .2398 | .2838 | 485 | 29.2 | |
| 2/2 | .0391 | .0457 | .0709 | .2512 | .2935 | 486 | 23.9 | |
| B | 8/2 | .6321 | .6679 | .8731 | .2909 | .3074 | 485.1 | 7.9 |
| 7/4 | .4722 | .5217 | .7294 | .2740 | .3027 | 486.4 | 14.7 | |
| 6/5 | .3778 | .4202 | .7241 | .2482 | .2761 | 482.7 | 26.9 | |
| 5/6 | .2317 | .2731 | .5203 | .2260 | .2664 | 483.5 | 36.0 | |
| 4/6 | .1437 | .1661 | .3646 | .2131 | .2463 | 481.7 | 42.9 | |
| 3/5 | .0977 | .1076 | .2493 | .2150 | .2367 | 480.1 | 43.4 | |
| 2/4 | .0398 | .0447 | .0981 | .2180 | .2448 | 480.9 | 41.3 | |
| PB | 8/2 | .6417 | .6546 | .8702 | .2962 | .3022 | 477.2 | 6.8 |
| 7/4 | .4477 | .4261 | .7350 | .2722 | .2809 | 478.6 | 17.6 | |
| 6/6 | .3800 | .3894 | .6988 | .2588 | .2652 | 477.5 | 24.5 | |
| 5/8 | .2616 | .2653 | .5699 | .2385 | .2419 | 476.8 | 34.7 | |
| 4/10 | .1796 | .1773 | .5248 | .2038 | .2011 | 476.1 | 52.1 | |
| 3/9 | .0993 | .0859 | .3191 | .1969 | .1703 | 472.2 | 59.0 | |
| 2/2 | .0430 | .0430 | .0972 | .2347 | .2348 | 476.1 | 37.0 | |
| P | 8/2 | .6272 | .6161 | .7907 | .3084 | .3029 | 556 c | 5.0 |
| 7/3 | .5324 | .5110 | .6536 | .3137 | .3011 | 535 c | 6.7 | |
| 6/4 | .4245 | .3936 | .5650 | .3069 | .2846 | 556 c | 12.1 | |
| 5/6 | .2785 | .2480 | .4076 | .2982 | .2655 | 561 c | 18.2 | |
| 4/6 | .2080 | .1727 | .3124 | .3001 | .2492 | 558 c | 25.0 | |
| 3/6 | .1271 | .1022 | .2216 | .2819 | .2266 | 564 c | 30.9 | |
| 2/3 | .0509 | .0436 | ,0856 | .2826 | .2420 | 565 c | 24.7 | |
| RP | 8/2 | .6710 | .6525 | .7599 | .3221 | .3132 | 494 c | 3.5 |
| 7/4 | .6029 | .5508 | .6600 | .3324 | .3037 | 498 c | 9.5 | |
| 6/4 | .4223 | .3776 | .4834 | .3291 | .2942 | 506 c | 12.5 | |
| 5/6 | .2968 | .2509 | .3263 | .3396 | .2871 | 504 c | 17.2 | |
| 4/6 | .1991 | .1555 | .2311 | .3399 | .2655 | 513 c | 26.0 | |
| 3/6 | .1134 | .0850 | .1337 | .3414 | .2559 | 516 c | 30.2 | |
| 2/2 | .0514 | .0436 | .0606 | .3302 | .2802 | 514 c | 18.3 | |
TABLE V. Average values of Y for samples in 1919 and 1926 tests. These values are computed from the data of Tables II, III and IV, except for the neutral samples, for which the values are taken from Bureau of Standards Technologic Paper No. 167.
| Munsell Value | ||||
| 1919 | 1926 Chromatic Samples | |||
| Chromatic Samples | Neutral Samples[1] | Illumination at | ||
| 45° | Diffuse | |||
| Y | Y | Y | Y | |
| 9/ | 0.772 | |||
| 8/ | .602 | .0.6248 | 0.6274 | |
| 7/ | 0.4787 | .465 | .4991 | .5031 |
| 6/ | .343 | .3923 | .3947 | |
| 5/ | .2460 | .234 | .2456 | .2503 |
| 4/ | -161 | .1719 | .1763 | |
| 3/ | .0922 | .090 | .0922 | .0964 |
| 2/ | 041 | .0457 | 0.487 | |
| 1/ | .018 | |||
Figure 2 is one of the ten illustrations in the original report which show the deviations between the data as adopted for the diffuse-normal and the 45°-normal conditions. These blue-green samples have been selected for illustration because they show the greatest variation in dominant wave-length. Figure 2 also illustrates the general tendency for the apparent reflectances for the diffuse-normal conditions to be higher than those for the 45°-normal conditions.
Colormetric Computations
- ↑ Compound for noon sunlight. The Value of Y for neutral 9/ of which is the most selective of the neutral samples, is 0.763 for I.C.I. Illuminant C. Difference in illuminant therefore will not account for the differences between the values of Y for the neutral samples and the average values of Y for the chromatic samples.
