The authors investigate monocular perception of egocentric distance and advocate the necessity of a perception-action approach because calibration is intrinsic to definite distance perception. They used a helmet mounted camera and display to isolate optic flow generated by head movement towards a target and analyzed reaches to place a stylus either in a target hole (Experiments 1, 2 and 4) or aligned under a target surface (Experiment 3). The conclusions were that binocular distance perception is accurate; monocular distance perception yields compression that is not eliminated by feedback; but feedback is used to eliminate underestimation generated by restricting the visual field.