The problem relates to the effect of distance judgment under conditions of semi-scotopic vision. The levels of illumination ranged between .01 and 1.30 foot candles. Two series of experiments are reported. The first series used 16 subjects with illumination levels ranging between .04 and 1.30 foot candles. The second series used seven subjects between the ranges of .01 and .04 foot candles. Time and errors were used as the criteria of performance. Both showed considerable variation throughout the series but greatest effects are noted below .03 foot candles. The time for setting varied more than the error score. Differential settings for colored test objects are given.
Proceedings of the Iowa Academy of Science
© Copyright 1942 by the Iowa Academy of Science, Inc.
Lauer, A. R. and Winterstein, Merwyn
"The Effect of Varying Illumination on Distance Perception of Objects Subtending,"
Proceedings of the Iowa Academy of Science, 49(1), 449-449.
Available at: https://scholarworks.uni.edu/pias/vol49/iss1/90