Table I
Values of the Required Luminance B r in ft-L,a as a Function of the Equivalent
Contrast C
C
˜
B r 0.451 2985 0.452 2680 0.453 2450 0.454 2305 0.455 2180 0.456 2090 0.457 2000 0.458 1890 0.459 1820 0.460 1760 0.461 1690 0.462 1640 0.463 1580 0.464 1535 0.465 1490 0.466 1440 0.467 1405 0.468 1360 0.469 1320 0.470 1280 0.471 1250 0.472 1210 0.473 1180 0.474 1150 0.475 1125 0.476 1100 0.477 1060 0.478 1035 0.479 1020 0.480 994 0.481 965 0.482 934 0.483 906 0.484 893 0.485 866 0.486 847 0.487 829 0.488 804 0.489 789 0.490 774 0.491 759 0.492 744 0.493 724 0.494 706 0.495 697 0.496 679 0.497 666 0.498 655 0.499 644 0.500 632 0.501 621 0.502 606 0.503 595 0.504 580 0.505 572 0.506 557 0.507 544 0.508 538 0.509 526 0.510 514 0.511 508 0.512 496 0.513 487 0.514 479 0.515 467 0.516 460 0.517 452 0.518 444 0.519 437 0.520 428 0.521 422 0.522 416 0.523 408 0.524 402 0.525 396 0.526 388 0.527 382 0.528 374 0.529 368 0.530 362 0.531 354 0.532 348 0.533 342 0.534 334 0.535 328 0.536 322 0.537 316 0.538 312 0.539 304 0.540 298 0.541 293 0.542 289 0.543 284 0.544 279 0.545 275 0.546 270 0.547 264 0.548 259 0.549 255 0.550 252 0.551 248 0.552 243 0.553 241 0.554 239 0.555 234 0.556 229 0.557 226 0.558 222 0.559 219 0.560 216 0.561 213 0.562 210 0.563 206 0.564 202 0.565 199 0.566 196 0.567 193 0.568 190 0.569 187 0.570 184 0.571 182 0.572 179 0.573 177 0.574 175 0.575 172 0.576 170 0.577 166 0.578 164 0.579 161 0.580 159 0.581 156 0.582 155 0.583 152 0.584 150 0.585 147 0.586 145 0.587 142 0.588 141 0.589 140 0.590 138 0.591 136 0.592 135 0.593 133 0.594 132 0.595 130 0.596 128 0.597 126 0.598 125 0.599 124 0.600 122 0.601 120 0.602 118 0.603 117 0.604 115 0.605 114 0.606 112 0.607 110 0.608 108 0.609 107 0.610 106 0.611 104 0.612 102 0.613 101 0.614 100 0.615 98.4 0.616 96.8 0.617 96.0 0.618 94.4 0.619 92.8 0.620 92.0 0.621 90.8 0.622 89.8 0.623 88.4 0.624 87.4 0.625 86.3 0.626 84.9 0.627 84.2 0.628 82.9 0.629 81.7 0.630 81.1 0.631 79.9 0.632 78.7 0.633 77.8 0.634 76.9 0.635 76.0 0.636 75.1 0.637 74.0 0.638 73.2 0.639 72.5 0.640 72.0 0.641 71.0 0.642 70.0 0.643 69.5 0.644 68.5 0.645 67.5 0.646 66.5 0.647 65.8 0.648 65.3 0.649 64.7 0.650 63.9 0.651 63.3 0.652 62.7 0.653 61.9 0.654 61.1 0.655 60.7 0.656 59.9 0.657 59.3 0.658 58.7 0.659 57.9 0.660 57.5 0.661 56.9 0.662 56.3 0.663 55.5 0.664 54.7 0.665 54.1 0.666 53.5 0.667 52.7 0.668 51.9 0.669 51.5 0.670 51.1 0.671 50.3 0.672 49.5 0.673 48.9 0.674 48.4 0.675 47.8 0.676 47.5 0.677 46.9 0.678 46.3 0.679 46.0 0.680 45.4 0.681 45.0 0.682 44.5 0.683 44.0 0.684 43.6 0.685 43.0 0.686 42.6 0.687 42.0 0.688 41.5 0.689 40.9 0.690 40.4 0.691 40.2 0.692 39.9 0.693 39.3 0.694 39.0 0.695 38.7 0.696 38.3 0.697 38.0 0.698 37.7 0.699 37.4 0.700 37.1 0.701 36.3 0.702 35.9 0.703 35.6 0.704 35.3 0.705 34.9 0.706 34.7 0.707 34.4 0.708 34.1 0.709 33.7 0.710 33.3 0.711 32.9 0.712 32.7 0.713 32.4 0.714 32.1 0.715 31.7 0.716 31.4 0.717 31.1 0.718 30.9 0.719 30.7 0.720 30.5 0.721 30.2 0.722 30.0 0.723 29.7 0.724 29.4 0.725 29.1 0.726 29.0 0.727 28.8 0.728 28.5 0.729 28.2 0.730 28.0 0.731 27.8 0.732 27.5 0.733 27.2 0.734 27.0 0.735 26.8 0.736 26.6 0.737 26.2 0.738 26.0 0.739 25.8 0.740 25.6 0.741 25.5 0.742 25.2 0.743 25.0 0.744 24.8 0.745 24.5 0.746 24.4 0.747 24.2 0.748 24.0 0.749 23.9 0.750 23.6 0.751 23.4 0.752 23.3 0.753 23.1 0.754 22.9 0.755 22.8 0.756 22.6 0.757 22.4 0.758 22.3 0.759 2212 0.760 22.0 0.761 21.8 0.762 21.6 0.763 21.5 0.764 21.3 0.765 21.1 0.766 20.9 0.767 20.8 0.768 20.6 0.769 20.5 0.770 20.3 0.771 20.2 0.772 20.0 0.773 19.8 0.774 19.7 0.775 19.5 0.776 19.3 0.777 19.2 0.778 19.1 0.779 19.0 0.780 18.8 0.781 18.7 0.782 18.6 0.783 18.4 0.784 18.3 0.785 18.2 0.786 18.0 0.787 17.8 0.788 17.7 0.789 17.6 0.790 17.4 0.791 17.3 0.792 17.2 0.793 17.1 0.794 17.0 0.795 16.9 0.796 16.8 0.797 16.6 0.798 16.5 0.799 16.3 0.800 16.2 0.801 16.1 0.802 16.0 0.803 15.9 0.804 15.8 0.805 15.6 0.806 15.5 0.807 15.4 0.808 15.3 0.809 15.2 0.810 15.1 0.811 15.0 0.812 14.9 0.813 14.8 0.814 14.8 0.815 14.7 0.816 14.6 0.817 14.5 0.818 14.4 0.819 14.3 0.820 14.2 0.821 14.1 0.822 14.0 0.823 13.9 0.824 13.8 0.825 13.7 0.826 13.6 0.827 13.6 0.828 13.5 0.829 13.4 0.830 13.3 0.831 13.2 0.832 13.1 0.833 13.0 0.834 13.0 0.835 12.9 0.836 12.8 0.837 12.7 0.838 12.6 0.839 12.5 0.840 12.5 0.841 12.4 0.842 12.3 0.843 12.2 0.844 12.1 0.845 12.0 0.846 12.0 0.847 11.9 0.848 11.8 0.849 11.8 0.850 11.7 0.851 11.6 0.852 11.5 0.853 11.4 0.854 11.4 0.855 11.3 0.856 11.3 0.857 11.2 0.858 11.1 0.859 11.0 0.860 11.0 0.861 10.9 0.862 10.8 0.863 10.7 0.864 10.7 0.865 10.6 0.866 10.6 0.867 10.5 0.868 10.5 0.869 10.4 0.870 10.3 0.871 10.3 0.872 10.2 0.873 10.2 0.874 10.1 0.875 10.1 0.876 10.0
a The value in ft-L multiplied by 3.426 yields the value in cd/m
2 .
Table II
Experimental Values of CRF Target 30–4–2 Horizontal Task Location
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 0.836 0.837 0.856 0.859 0.837 Fixtures, prisms 0.788 0.789 0.847 0.882 0.896 Fixtures, polarizers 0.830 0.838 0.880 0.904 0.908 Ceiling, diffusers 0.957 0.980 0.988 0.988 0.971 Ceiling, polarizers 0.963 0.989 1.003 1.016 1.018
Table III
Experimental Values of CRF Target 30–4–2 Vertical Task Location
Installation On-axis viewing angle Fixtures, diffusers 1.046 Fixtures, prisms 1.051 Fixtures, polarizers 1.057 Ceiling, diffusers 1.030 Ceiling, polarizers 1.037
Table IV
Experimental Values of DGF Horizontal Task Location
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 1.026 1.026 1.028 1.029 1.029 Fixtures, prisms 1.027 1.027 1.030 1.030 1.030 Fixtures, polarizers 1.028 1.028 1.030 1.031 1.031 Ceiling, diffusers 1.025 1.025 1.027 1.028 1.028 Ceiling, polarizers 1.028 1.028 1.029 1.030 1.030
Table V
Experimental Values of DGF Vertical Task Location
Installation On-axis viewing angle Fixtures, diffusers 1.027 Fixtures, prisms 1.025 Fixtures, polarizers 1.025 Ceiling, diffuser 1.021 Ceiling, polarizers 1.023
Table VI
Values of the Variable k as a Function of θ
θ k 0–45° 450 — — — — 50° 473 55° 506 60° 550 65° 602 70° 661 75° 729 80° 800 — — — —
Table VII
Experimental Values of TAF Horizontal Task Location
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 0.912 0.912 0.914 0.914 0.914 Fixtures, prisms 0.932 0.932 0.931 0.931 0.931 Fixtures, polarizers 0.926 0.926 0.925 0.925 0.925 Ceiling, diffusers 0.928 0.928 0.928 0.928 0.928 Ceiling, polarizers 0.954 0.954 0.955 0.955 0.955
Table VIII
Experimental Values of TAF Vertical Ceiling Location
Installation On-axis viewing angle Fixtures, diffusers 0.889 Fixtures, prisms 0.882 Fixtures, polarizers 0.882 Ceiling, diffusers 0.938 Ceiling, polarizers 0.945
Table IX
Individual Values of TAF Horizontal Task Location 40° Viewing Angle
Installation N E S W U R D L Fixtures, diffusers 0.988 0.999 0.986 0.993 0.958 0.998 0.989 1.000 Fixtures, prisms 0.999 0.995 0.983 0.998 0.981 0.990 0.989 0.994 Fixtures, polarizers 0.995 0.995 0.985 0.997 0.971 0.993 0.988 0.998 Ceiling, diffusers 0.987 0.996 0.991 0.996 0.969 0.998 0.992 0.997 Ceiling, polarizers 0.995 1.000 0.990 1.000 0.977 1.000 0.992 1.000
Table X
Individual Values of TAF Vertical Task Location
Installation U R D L Fixtures, diffusers 0.907 0.998 0.987 0.994 Fixtures, prisms 0.891 0.999 0.992 0.998 Fixtures, polarizers 0.899 0.997 0.991 0.993 Ceiling, diffusers 0.956 0.998 0.988 0.996 Ceiling, polarizers 0.957 1.000 0.990 0.999
Table XI
Values of Task Background Luminance Horizontal Task Location*
Installation E h
(ft-c)Viewing angle (degrees from vertical)
10 25 40 50 60 Fixtures, diffusers 150 98.5 98.8 108 111 112 Fixtures, prisms 232 154 154 174 172 172 Fixtures, polarizers 210 146 146 162 162 162 Ceiling, diffusers 208 138 143 148 152 152 Ceiling, polarizers 218 153 156 163 165 166
Table XII
Values of Task Background Luminance Vertical Task Location*
Installation E v (ft-c)On-axis viewing angle Fixtures, diffusers 75.8 53.7 Fixtures, prisms 94.0 67.3 Fixtures, polarizers 95.0 72.0 Ceiling, diffusers 112 76.7 Ceiling, polarizers 106 74.8
Table XIII
Task Background Reflectances Horizontal Task Location
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 0.657 0.658 0.722 0.740 0.746 Fixtures, prisms 0.662 0.664 0.749 0.742 0.742 Fixtures, polarizers 0.698 0.698 0.772 0.774 0.772 Ceiling, diffusers 0.663 0.688 0.713 0.730 0.732 Ceiling, polarizers 0.702 0.713 0.745 0.756 0.760
Table XIV
Task Background Reflectances Vertical Task Location
Installation On-axis viewing angle Fixtures, diffusers 0.708 Fixtures, prisms 0.716 Fixtures, polarizers 0.758 Ceiling, diffusers 0.685 Ceiling, polarizers 0.706
Table XV
Values of CSF, 70 ft-c Sphere Reference Horizontal Task Location
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 1.091 1.092 1.105 1.107 1.108 Fixtures, prisms 1.152 1.152 1.168 1.168 1.168 Fixtures, polarizers 1.147 1.147 1.160 1.160 1.160 Ceiling, diffusers 1.138 1.144 1.148 1.152 1.152 Ceiling, polarizers 1.152 1.155 1.160 1.162 1.164
Table XVI
Values of CSF, 70 ft-c Sphere Reference Vertical Task Location
Installation On-axis viewing angle Fixtures, diffusers 1.008 Fixtures, prisms 1.039 Fixtures, polarizers 1.049 Ceiling, diffusers 1.058 Ceiling, polarizers 1.050
Table XVII
Values of LPI and TVI Horizontal Task Location
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 0.853 0.856 0.888 0.893 0.871 Fixtures, prisms 0.868 0.870 0.948 0.988 1.004 Fixtures, polarizers 0.907 0.914 0.972 1.000 1.005 Ceiling, diffusers 1.037 1.065 1.082 1.085 1.067 Ceiling, polarizers 1.090 1.120 1.143 1.161 1.165
Table XVIII
Values of LPI and TVI Vertical Task Location
Installation On-axis viewing angle Fixtures, diffusers 0.962 Fixtures, prisms 0.987 Fixtures, polarizers 1.000 Ceiling, diffusers 1.043 Ceiling, polarizers 1.053
Table XIX
Values of ESI (ft-c) Horizontal Task Location
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 24.6 25.0 30.9 32.2 28.0 Fixtures, prisms 27.0 27.5 46.9 63.0 72.0 Fixtures, polarizers 35.5 37.0 56.3 70.0 72.3 Ceiling, diffusers 91.5 113 131 132 115 Ceiling, polarizers 136 171 209 230 237
Table XX
Values of ESI (ft-c) Vertical Task Location
Installation On-axis viewing angle Fixtures, diffusers 52.2 Fixtures, prisms 63.0 Fixtures, polarizers 70.0 Ceiling, diffusers 97.5 Ceiling, polarizers 105
Table XXI
Illuminance to Match 70 ft-c Sphere Reference Horizontal Task Location TVI = 1
Viewing angle (degrees from vertical)
Installation 10 25 40 50 60 Fixtures, diffusers 612 590 417 399 501 Fixtures, prisms 864 820 367 258 227 Fixtures, polarizers 518 470 272 210 201 Ceiling, diffusers 154 123 109 108 123 Ceiling, polarizers 110 88.8 75.6 67.6 64.3
Table XXII
Illuminance to Match 70 ft-c Sphere Reference Vertical Task Location TVI = 1
Installation On-axis viewing angle Fixtures, diffusers 102 Fixtures, prisms 103 Fixtures, polarizers 95.0 Ceiling, diffusers 83.1 Ceiling, polarizers 69.3