Color-matching functions (CMFs) were derived with the Maxwell method for 10 subjects using two field,conditions: (1) horizontally bisected circular 10 degrees and (2) vertically bisected rectangular 102 degrees (wide) X 50 degrees (high). The primary set was composed of 453-533-601 nm components with a mean full-width at half maximum of 18.3 nm; the reference field was illuminated with daylight fluorescent lamplight. Field size had a significant effect on the shape of the resulting CMFs. Under the large-field conditions subjects were less sensitive to shorter wavelengths as characterized with the (b) over bar function and had higher sensitivities to the longer wavelengths as characterized with the (r) over bar function. (C) 2005 Wiley Periodicals, Inc.