Table I
Contrast sensitivity for sine-wave test object, constant luminance, 20 ft-L; visual angle, 6°. ν0=frequency in cycles or lines/mm in object space. νr=frequency in cycles or lines/mm on retina.
Obj. space ν0 | 10-in. viewing distance | 14-in. viewing distance | 35-in. viewing distance | 56-in. viewing distance | 10-ft viewing distance |
---|
Retina νr | CT | Retina νr | CT | Retina νr | CT | Retina νr | CT | Retina νr | CT |
---|
0.05 | 0.747 | 0.01120 | 1.046 | 0.0091 | 2.615 | 0.0041 | 4.184 | 0.0043 | 8.965 | 0.0053 |
0.075 | 1.120 | 0.00682 | 1.569 | 0.0067 | 3.922 | 0.0027 | 6.275 | 0.0027 | 13.45 | 0.0040 |
0.15 | 2.241 | 0.00356 | 3.138 | 0.0036 | 7.844 | 0.0019 | 12.55 | 0.0025 | 26.89 | 0.0050 |
0.25 | 3.735 | 0.00308 | 5.229 | 0.0026 | 13.07 | 0.0019 | 20.92 | 0.0037 | 44.82 | 0.0096 |
0.50 | 7.471 | 0.00202 | 10.46 | 0.0034 | 26.15 | 0.0041 | 41.84 | 0.0096 | 89.65 | 0.0310 |
0.60 | 8.965 | 0.00289 | 12.55 | 0.0036 | 31.38 | 0.0066 | 50.20 | 0.0130 | 107.6 | 0.0550 |
0.80 | 11.95 | 0.00566 | 16.73 | 0.0038 | 41.84 | 0.0100 | 66.94 | 0.0230 | 143.4 | 0.1790 |
1.00 | 14.94 | 0.00906 | 20.92 | 0.0034 | 52.29 | 0.0130 | 83.67 | 0.0410 | 179.3 | 0.2740 |
1.20 | 17.93 | 0.01090 | 25.10 | 0.0047 | 62.75 | 0.0210 | 100.4 | 0.0600 | ⋯ | ⋯ |
1.60 | 23.91 | 0.01500 | 33.47 | 0.0083 | 83.67 | 0.0400 | 133.9 | 0.1120 | ⋯ | ⋯ |
1.80 | 26.89 | 0.01520 | 37.65 | 0.0100 | 94.13 | 0.0500 | 150.6 | 0.1590 | ⋯ | ⋯ |
2.40 | 35.86 | 0.02110 | 50.20 | 0.0180 | 125.5 | 0.1790 | 200.8 | 0.8410 | ⋯ | ⋯ |
2.80 | 41.84 | 0.02330 | 58.57 | 0.0240 | 146.4 | 0.3050 | ⋯ | ⋯ | ⋯ | ⋯ |
3.60 | 53.79 | 0.04570 | 75.30 | 0.0390 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ |
4.00 | 59.76 | 0.05470 | 83.67 | 0.0500 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ |
5.00 | 74.71 | 0.06450 | 104.6 | 0.1080 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ |
6.00 | 89.65 | 0.10900 | 125.5 | 0.1920 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ |
7.00 | 104.6 | 0.21600 | 146.4 | 0.2830 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ |
Table II
Contrast sensitivity for square-wave test object, constant luminance, 20 ft-L; visual angle, 6°. ν0=frequency in cycles or lines/mm in object space. νr=frequency in cycles or lines/mm on retina.
Obj. space ν0 | 10-in. viewing distance | 14-in. viewing distance | 35-in. viewing distance | 56-in. viewing distance |
---|
Retina νr | CT | Retina νr | CT | Retina νr | CT | Retina νr | CT |
---|
0.05 | 0.747 | 0.0026 | 1.046 | 0.0029 | 2.615 | 0.0025 | 4.184 | 0.0019 |
0.075 | 1.120 | 0.0028 | 1.569 | 0.0023 | 3.922 | 0.0024 | 6.275 | 0.0017 |
0.10 | ⋯ | ⋯ | 2.092 | 0.0020 | 5.229 | 0.0021 | 8.367 | 0.0015 |
0.125 | ⋯ | ⋯ | ⋯ | ⋯ | 6.537 | 0.0021 | 10.46 | 0.0015 |
0.15 | 2.241 | 0.0017 | 3.138 | 0.0018 | 7.844 | 0.0017 | 12.55 | 0.0015 |
0.175 | ⋯ | ⋯ | ⋯ | ⋯ | 9.151 | 0.0021 | 14.64 | 0.0023 |
0.20 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | 16.73 | 0.0022 |
0.25 | 3.735 | 0.0019 | 5.229 | 0.0016 | 13.07 | 0.0024 | 20.92 | 0.0031 |
0.30 | ⋯ | ⋯ | ⋯ | ⋯ | 15.69 | 0.0027 | 25.10 | 0.0035 |
0.375 | ⋯ | ⋯ | 7.844 | 0.0018 | ⋯ | ⋯ | ⋯ | ⋯ |
0.50 | 7.471 | 0.0019 | 10.46 | 0.0019 | 26.15 | 0.0037 | ⋯ | ⋯ |
0.625 | 9.338 | 0.0028 | 13.07 | 0.0023 | 32.68 | 0.0056 | ⋯ | ⋯ |
0.75 | 11.21 | 0.0026 | 15.69 | 0.0033 | ⋯ | ⋯ | ⋯ | ⋯ |
0.875 | ⋯ | ⋯ | ⋯ | ⋯ | 45.76 | 0.0110 | ⋯ | ⋯ |
1.00 | 14.94 | 0.0030 | 20.92 | 0.0041 | 52.29 | 0.0140 | ⋯ | ⋯ |
1.25 | 18.68 | 0.0095 | 26.15 | 0.0080 | 65.37 | 0.0230 | ⋯ | ⋯ |
1.50 | 22.41 | 0.0130 | 31.38 | 0.0086 | 78.44 | 0.0310 | ⋯ | ⋯ |
2.50 | 37.40 | 0.0230 | 52.29 | 0.0340 | 130.7 | 0.1620 | ⋯ | ⋯ |
3.00 | 44.80 | 0.0480 | 62.75 | 0.0550 | ⋯ | ⋯ | ⋯ | ⋯ |
4.00 | 59.76 | 0.0770 | 83.67 | 0.1140 | ⋯ | ⋯ | ⋯ | ⋯ |
5.00 | 74.71 | 0.1680 | 104.6 | 0.2340 | ⋯ | ⋯ | ⋯ | ⋯ |
6.00 | 89.65 | 0.2680 | 125.5 | 0.5060 | ⋯ | ⋯ | ⋯ | ⋯ |
7.00 | ⋯ | ⋯ | 146.4 | 0.9320 | ⋯ | ⋯ | ⋯ | ⋯ |
8.00 | 119.5 | 0.5500 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ |
9.00 | 134.5 | 0.7350 | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ | ⋯ |
Table III
Contrast sensitivity for sine-wave test object, viewing distance, 35 in.; visual angle, 6°. ν0=frequency in cycles or lines/mm in object space. νr=frequency in cycles or lines/mm on retina.
Obj. space ν0 | Retina νr | CT |
---|
20 ft-L | 300 ft-L |
---|
0.05 | 2.615 | 0.0041 | 0.00477 |
0.075 | 3.922 | 0.0027 | 0.00289 |
0.15 | 7.844 | 0.0019 | 0.00173 |
0.25 | 13.07 | 0.0019 | 0.00156 |
0.50 | 26.15 | 0.0041 | 0.00193 |
0.60 | 31.38 | 0.0066 | 0.00275 |
0.80 | 41.84 | 0.0100 | 0.00395 |
1.00 | 52.29 | 0.0130 | 0.00522 |
1.20 | 62.75 | 0.0210 | 0.00627 |
1.60 | 83.67 | 0.0400 | 0.01240 |
1.80 | 94.13 | 0.0500 | 0.02300 |
2.40 | 125.5 | 0.1790 | 0.03530 |
Table IV
Effect of viewing distance on the limit of resolution, constant luminance, 20 ft-L.
| Limit of resolution, cycles or lines/mm for |
---|
|
|
---|
Viewing distance (inches) | Sine-wave test object | Square-wave test object |
---|
On the retina νr | In object space ν0 | On the retina νr | In object space ν0 |
---|
10 | 155 | 10.4 | 145 | 9.71 |
14 | 193 | 9.23 | 150 | 7.17 |
35 | 215 | 4.11 | 210 | 4.02 |
56 | 225 | 2.69 | ⋯ | ⋯ |
120 | 250 | 1.39 | ⋯ | ⋯ |