Figure 1.

Personal objects brought for the study by participants shown under neutral daylight illumination (top left) and the four experimental filter conditions (A–D). In the top right, we show details of several objects under the four colorful illuminants to illustrate how different the reflected wavelength composition and cone excitations are under each illumination. These images were taken with a Nikon D70 digital camera with the white balancing turned off. They were not colorimetrically calibrated and only serve illustration purposes. The objects were never seen by the observers during the experiments.