ROD INFLUENCE ON HUE-SCALING FUNCTIONS

Rod influence on hue appearance of spectral lights was characterized b y comparing the scaling of red, green, yellow, and blue hue sensations for an 8 degrees-diameter, 7 degrees-eccentric test spot under condit ions that minimized (cone plateau:) and maximized (dark adapted) rod i nfluence at two mesopic light levels (1.5 and 3.0 log sceptic trolands ). At the lower light level, the hue-scaling functions showed that rod signals influenced the spectral range and magnitude of all four prima ry hues. The rod influence could not be characterized. as a ubiquitous augmentation or diminution of ally hue over the entire spectrum. This constrains models of rod influence on color vision. (C) 1998 Elsevier Science Ltd. All rights reserved.