Simulation of a Star Field

Abstract

Twelve observers were asked to estimate the realism of projected star fields. The results clearly indicate that maximum realism is obtained from a star field which has the following characteristics: (1) sky (background) luminance is quite low, preferably as in the outer space sky of 10^-5 candelas per square meter; (2) individual stars are small (1 minute of visual angle), appearing as point sources; and, (3) simulated stars are relatively bright, casting an illumination of about 10^-8 ft-candles upon the eye of the observer (approximately first to third magnitude, average). One important overall characteristic of these conditions is that of virtually infinite contrast between a point source and its background, a true star characteristic as pointed out by Middleton. Any departures from these conditions will affect the apparent realism of the display, as shown by the experimental results.