Effects of Target Separation and Distance on Commonplace Binocular Depth Discrimination

Two experiments were performed to determine the effects of lateral target separation on commonplace binocular depth perception and to extend previous studies of the effects of distance to the range of 10 to 100 feet. Separations of 1.4 to 114.6 minutes were not found to have a differential effect except at the greater distances. This is attributed to a loss of visual rather than depth acuity. The effects of viewing distance were found to be consistent with previous studies of the distance effect. Differences in the effects of distance were found between sophisticated and unsophisticated subjects; the former tended to make finer discriminations especially at the greater distances.