Judgments of Relative Distance Based on Separate 2-D TV Views’

An experiment was conducted to determine human capabilities for making judgments of relative distance based on cues obtained from two ordinary, tw+dimensional, closed-circuit television systems. The two cameras were placed so that their lines-of sight converged symmetrically upon the mid-point between the two rods of a mdixed Howard-Dolman depth perception apparatus. Four camera lines-ofsight con-vergence angles were investigated: IS”, 30”. @”, and 90”. Difference thresholds for relative depth percep-tion were determined for 24 subjects by the psychophysical Method of Limits. Thresholds were on the order of 12-13 minutes of an: in terms of the parallactic diffeerence angle for the camera lines-of-sight. The results are related to the design of viewing systems for remote operations. Adequate provision for visual feedback is criti-cal to effective remote-handling operations. Re-strictions imposed by shielding or the necessity for working at great distances from the task area often make unaided viewing impossible. Under such circumstances, the primary visual display may be a closed-circuit television system monitor