Crawford B H, Palmer D A
Vision Res. 1985;25(6):863-6. doi: 10.1016/0042-6989(85)90194-4.
The scotopic visibility curves of two observers have been measured by determining their absolute thresholds for monochromatic lights and by direct comparison matching just above the threshold, in a 10 degree field with its centre 15 degrees above the fixation point. The results were all similar to the CIE scotopic curve. However, the threshold results in the long-wave part of the spectrum could be considerably modified by subliminal red and green lights. This is consistent with Drum's observations of sub-additivity at threshold. Above threshold, supra-additivity was obtained. A scotopic curve is evidently a non-linear combination of rod and cone responses which varies with the conditions of observation.
通过测定两名观察者对单色光的绝对阈值，并在中心位于注视点上方15度的10度视野中，在阈值之上通过直接比较匹配，测量了他们的暗视觉可见度曲线。结果均与CIE暗视觉曲线相似。然而，光谱长波部分的阈值结果可能会受到阈下红光和绿光的显著影响。这与德拉姆对阈值下的次可加性的观察结果一致。在阈值之上，得到了超可加性。暗视觉曲线显然是杆体和锥体反应的非线性组合，它会随观察条件而变化。
