#### Table I

Observed and calculated visual transmissions, foveal.Observations with a 1-degree field, fixated within the fovea, and exposed for 1 second. Calculated visual transmissions, (*T*_{υ}), are based on foveal values of relative sensitivity (*K*_{λ}) taken from Fig. 4, and on the energy distribution of a black body at 3200°K. λ_{max} is the wave-length of maximum spectral visual transmission of each filter (Fig. 3). In the designations of the filters, J = Jena, C = Corning, and EBH designates a special group of infra-red filters manufactured by the Polaroid Corporation.

Filter | JRG-8 plus C 3961 | C 2600 | EBH 3 | EBH 5–27 |
---|

λ_{max} | 685 | 725 | 835 | 873 |

No. of observers | 54 | 48 | 39 | 54 |

I. Calc. log *T*_{υ} relative to 685 m*μ* filter | 0.00 | +0.03 | −3.30 | −3.90 |

II. Obs. log *T*_{υ} relative to 685 m*μ* filter | 0.00 | −0.09 | −3.23 | −3.91 |

III.
$$log\frac{\text{calculated}}{\text{observed values}}(\text{I}-\text{II})$$ | 0.00 | +0.12 | −0.07 | +0.01 |

#### Table II

Observed and calculated visual transmissions, peripheral.Observations made with a 1-degree field, fixated 8 degrees above the fovea and exposed for one second. Source at 3200°K; 2 cm of water in light path. Otherwise as in Table I.

Filter | JRG=8 plus C 3961 | C 2600 | EBH 3 | EBH 5–27 |
---|

λ_{max} | 685 | 725 | 838 | 874 |

No. of observers | 54 | 48 | 39 | 54 |

I. Obs. log *T*_{υ} relative to 685 m*μ* filter | 0.00 | +0.02 | −3.07 | −3.68 |

II. Calc. log *T*_{υ} based on Goodeve’s sensitivity function | 0.00 | +0.01 | −3.27 | −4.01 |

III. Discrepancy (I minus II) | 0.00 | +0.01 | +0.20 | +0.33 |

IV. Calc. log *T*_{υ} based on corrected sensitivity function | 0.00 | +0.09 | −3.10 | −3.62 |

V. Discrepancy (I minus IV) | 0.00 | −0.07 | +0.03 | −0.06 |

#### Table III

Variation, with respect to wave-length, of the ratio between foveal and peripheral thresholds in the red and infra-red.Measurements with the adaptometer described in text, using a 1-degree field and 1-second exposures. Peripheral fields fixated 8 degrees above the fovea.

Filter | JRG-8 plus C 3961 | C 2600 | C 2540 plus C 2600 | EBH 3 | EBH 5–27 | EBH 5–36 |
---|

λ_{max} | 685 | 725 | 762 | 835 | 873 | 908 |

No. of observers | 54 | 48 | 10 | 39 | 54 | 4 |

$$log\frac{\text{peripheral threshhold}}{\text{foveal threshhold}}$$ | +0.04 | −0.08 | −0.08 | −0.16 | −0.20 | −0.34 |

#### Table IV

Observed and calculated visual transmissions, peripheral.Data from 11 observers, using a 7-degree field, fixated peripherally and exposed for 1 second.

Filter | EBH 5–36 | EBH 5–8 | EBH 5–14 |
---|

λ_{max} | 908 | 928 | 944 |

I. Obs. log *T*_{υ} relative to 873 m*μ* filter | −0.75 | −1.18 | −1.44 |

II. Calc. log *T*_{υ} relative to 87.3 m*μ* filter, based on corrected sensitivity function | −0.76 | −1.14 | −1.46 |

Discrepancy (I minus II) | +0.01 | −0.04 | +0.02 |

#### Table V

Spectral sensitivity (*K*_{λ}) in the red and infra-red. Values selected as described in the text, for 1° test fields, exposed for 1 second, and fixated either within the fovea or 8° above the fovea in the wholly dark-adapted eye. The foveal values beyond 750 m*μ* are identical with those of Goodeve (1936). All spectral sensitivities are stated relative to the maximum sensitivity of the fovea, here taken as 1 (log*K*_{λ} =0.0); on this basis the maximum sensitivity of the peripheral area, at 505 m*μ*. is 363 (log*K*_{λ}=2.56).

Wavelength (m*μ*) | 1° oveal field | 1° field fixated 8° above fovea |
---|

log*K*λ | *K*_{λ} | log*K*_{λ} | *K*_{λ} |
---|

700 |
$$\overline{3}.55$$ | 3.55×10^{−3} |
$$\overline{3}.53$$ | 3.4×10^{−3} |

710 |
$$\overline{3}.23$$ | 1.7 |
$$\overline{3}.23$$ | 1.7 |

720 |
$$\overline{4}.92$$ | 8.3×10^{−4} |
$$\overline{4}.92$$ | 8.3×10^{−4} |

730 |
$$\overline{4}.61$$ | 4.1 |
$$\overline{4}.63$$ | 4.3 |

740 |
$$\overline{4}.31$$ | 2.0 |
$$\overline{4}.34$$ | 2.2 |

750 |
$$\overline{4}.02$$ | 1.04 |
$$\overline{4}.06$$ | 1.15 |

760 |
$$\overline{5}.71$$ | 5.1×10^{−5} |
$$\overline{5}.78$$ | 6.0×10^{−6} |

770 |
$$\overline{5}.43$$ | 2.7 |
$$\overline{5}.51$$ | 3.2 |

780 |
$$\overline{5}.15$$ | 1.4 |
$$\overline{5}.25$$ | 1.8 |

790 |
$$\overline{6}.87$$ | 7.4×10^{−6} |
$$\overline{6}.99$$ | 9.8×10^{−6} |

800 |
$$\overline{6}.59$$ | 3.9 |
$$\overline{6}.73$$ | 5.4 |

810 |
$$\overline{6}.34$$ | 2.2 |
$$\overline{6}.48$$ | 3.0 |

820 |
$$\overline{6}.08$$ | 1.2 |
$$\overline{6}.23$$ | 1.7 |

830 |
$$\overline{7}.83$$ | 6.8×10^{−7} |
$$\overline{7}.99$$ | 9.8×10^{−7} |

840 |
$$\overline{7}.57$$ | 3.75 |
$$\overline{7}.76$$ | 5.75 |

850 |
$$\overline{7}.34$$ | 2.2 |
$$\overline{7}.53$$ | 3.4 |

860 |
$$\overline{7}.11$$ | 1.3 |
$$\overline{7}.32$$ | 2.1 |

870 |
$$\overline{8}.88$$ | 7.5×10^{−8} |
$$\overline{7}.11$$ | 1.3 |

880 |
$$\overline{8}.65$$ | 4.5 |
$$\overline{8}.90$$ | 7.9×10^{−8} |

890 |
$$\overline{8}.45$$ | 2.8 |
$$\overline{8}.71$$ | 5.1 |

900 |
$$\overline{8}.23$$ | 1.7 |
$$\overline{8}.52$$ | 3.3 |

910 |
$$\overline{8}.03$$ | 1.07 |
$$\overline{8}.35$$ | 2.2 |

920 |
$$\overline{9}.83$$ | 6.6×10^{−9} |
$$\overline{8}.17$$ | 1.5 |

930 |
$$\overline{9}.62$$ | 4.2 |
$$\overline{8}.00$$ | 1.0 |

940 |
$$\overline{9}.43$$ | 2.7 |
$$\overline{9}.82$$ | 6.6×10^{−9} |

950 |
$$\overline{9}.24$$ | 1.7 |
$$\overline{9}.65$$ | 4.5 |

960 |
$$\overline{9}.05$$ | 1.1 |
$$\overline{9}.48$$ | 3.0 |

970 |
$$\overline{10}.87$$ | 7.4×10^{−10} |
$$\overline{9}.31$$ | 2.0 |

980 |
$$\overline{10}.69$$ | 4.9 |
$$\overline{9}.14$$ | 1.4 |

990 |
$$\overline{10}.51$$ | 3.2 |
$$\overline{10}.98$$ | 9.55×10^{−10} |

1000 |
$$\overline{10}.34$$ | 2.2 |
$$\overline{10}.82$$ | 6.6 |

1010 | | |
$$\overline{10}.66$$ | 4.6 |

1020 | | |
$$\overline{10}.51$$ | 3.2 |

1030 | | |
$$\overline{10}.35$$ | 2.2 |

1040 | | |
$$\overline{10}.19$$ | 1.55 |

1050 | | |
$$\overline{10}.04$$ | 1.1 |