title: Colour matching of isoluminant samples and backgrounds: a dimming effect.
abstract: Sequential asymmetrical colour matching of forty Munsell samples simulated under illuminant C and one of eight test illuminants was carried out. The subjects matched the appearance of each sample under illuminant C with its appearance under the test illuminant. Samples and background (N7) were presented for 1 s under the test illuminant and were isoluminant with each other. Subjects adjusted hue, chroma, and value under illuminant C. The experiments distinguished two groups of subjects; some observers needed to reduce the luminance of the sample to make a match while others did not. This 'dimming' occurred when the matches were close to cardinal axes, especially the tritanopic confusion line. A model of luminance and cone-opponent mechanisms contributing to brightness can account for the dimming effect. Details of analysis in cone-opponent space (L - M, L + M - S, L + M) are presented in the companion paper (Stanikunas et al, 2005 Perception 34 this issue).
authors.affiliation: Faculty of Life Sciences, Department of Optometry and Neuroscience, UMIST, PO Box 88, Manchester M60 1QD, UK. Ian.murray@umist.ac.uk
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Murray
authors.forename: Janus J
authors.initials: JJ
authors.lastname: Kulikowski
authors.forename: Rytis
authors.initials: R
authors.lastname: Stanikunas
authors.forename: Henrikas
authors.initials: H
authors.lastname: Vaitkevicius
authors.forename: Avsra
authors.initials: A
authors.lastname: Daugirdiene
mesh_terms: D000221:Adaptation, Ocular; D003118:Color Perception / Q000502:physiology*; D003119:Color Perception Tests; D015350:Contrast Sensitivity / Q000502:physiology; D006801:Humans; D008029:Lighting; D010775:Photic Stimulation; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology