Mustonen J, Rovamo J, Näsänen R
Department of Vision Sciences, Aston University, Birmingham, England.
Vision Res. 1993 Oct;33(15):2065-72. doi: 10.1016/0042-6989(93)90005-h.
Contrast sensitivity was measured as a function of retinal illuminance (I) for vertical cosine gratings of various circular areas (A) and spatial frequencies (f < or = 4 c/deg). Spatial frequency and grating diameter varied in inverse proportion to each other in order to keep the relative grating area (A x f2) constant at either 3.14, 12.6, 50.3, or 201 square cycles. At all grating areas and spatial frequencies contrast sensitivity in dim light first increased in proportion to the square root of retinal illuminance. Then the increase saturated and contrast sensitivity became independent of luminance level in bright light. For gratings with constant relative area contrast sensitivity functions were similar in shape and had the same maximum sensitivity but were shifted horizontally towards lower illuminances with decreasing spatial frequency. However, when replotted as a function of retinal illuminance divided by spatial frequency squared, contrast sensitivity functions fell on a common curve at all levels of relative retinal illuminance (I/f2).
测量了不同圆形面积（A）和空间频率（f≤4周/度）的垂直余弦光栅的对比敏感度与视网膜照度（I）的函数关系。空间频率和光栅直径成反比变化，以使相对光栅面积（A×f²）在3.14、12.6、50.3或201平方周期保持恒定。在所有光栅面积和空间频率下，暗光下的对比敏感度首先与视网膜照度的平方根成正比增加。然后增加趋于饱和，强光下的对比敏感度变得与亮度水平无关。对于具有恒定相对面积的光栅，对比敏感度函数形状相似，具有相同的最大敏感度，但随着空间频率降低，水平方向朝着较低照度移动。然而，当重新绘制为视网膜照度除以空间频率平方的函数时，在所有相对视网膜照度（I/f²）水平下，对比敏感度函数落在一条共同曲线上。
