Experimental Methods to investigate time-course of chromatic adaptation

Abstract

Two different experimental methods, method of adjustment and yellow/blue forced choice, were tested to investigate the time-course of chromatic adaptation. Inside the lighting booth, 2cm × 2cm square color stimulus was displayed on LCD and the surface of the display was covered with gray paper except for the stimulus area. The lighting of the booth was controlled to have 3,000 K or 6,500 K with 800 lux at the bottom of the booth. correlated color temperatures (CCT) of the booth lighting were changed from 6,500 K to 3,000K or 3,000K to 6,500K every two minutes. During the adjustment method experiment, the observers adjusted the stimulus to preserve an achromatic appearance. In the forced choice experiment, observers are asked to identify whether the stimuli are yellow or blue. In all experiments, evaluations were performed once every 5 seconds to track color appearance over time. The results showed that the observers had difficulties tracking the neutral colors using the adjustment method while the forced choice experiment showed the more consistent result.