The Legibility of Type As a Function of Reflectance of Background under Low Illumination
TUFTS UNIV MEDFORD MA
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The legibility of lower case type as a function of illumination level, reflectance of background, and type size was measured by means of speed and accuracy scores on a letter cross out test. Simulated red cockpit illumination was used, covering the range from 0.014 to 0.129 foot-candles. Red light reflectance of background was varied from 0.26 to 0.87. Type sizes were 6 and 8 point. Scores fell off at an accelerated rate with decreasing illumination and background reflectance, and were lower under all conditions for 6 than for 8 point type. The specific application of these data to chart design will be covered in a subsequent report.
- Anatomy and Physiology
- Human Factors Engineering and Man Machine Systems