The model cone mosaic was a hexagonal mosaic in which cone density, cone aperture, and outer segment length all varied with eccentricity according to measurements by Curcio et al. (
1991). The construction of such mosaics is described in detail in Cottaris et al. (
2018). The peak cone density was 204,213 cones/mm
2, with a corresponding minimum cone spacing of 2.36 microns, which is within the range of foveal densities reported by Curcio et al. (
1991). There were 9629 cones in all, 6167 (64%) L cones, 3,085 (32%) M cones, and 377 (4%) S cones, corresponding to current views on the relative numbers of cones of each class in the typical human retina (Hofer, Carroll, Neitz, Neitz, & Williams,
2005). There were no S cones in the central 0.15°, with a semiregular arrangement of S cones outside this region. The non-S cones were assigned as L or M randomly with 2:1 as the expected L:M ratio. Photopigment absorbance for the L, M, and S cones was taken from the CIE
2006 standard (CIE,
2006), and absorption by the foveal macular pigment (Stockman, Sharpe, & Fach,
1999) was incorporated. These choices, together with that used for lens density above, yield the CIE (
2006) 2° cone fundamentals. We assumed a quantal efficiency for cone photopigment of 0.67 (Rodieck,
1998) and a foveal cone inner segment acceptance area of 1.96 um
2, an area that sits between those provided by Kolb (
http://webvision.med.utah.edu) and Rodieck (
1998). We assumed a mean rate of spontaneous isomerizations of 100/cone-sec, consistent with estimates obtained psychophysically but lower than those obtained physiologically (see Koenig & Hofer,
2011). We used a cone integration time of 50 ms and computed the mean number of isomerizations of each cone in response to each image. From the mean number of isomerizations, we can simulate the number of isomerizations on an individual trial, because trial-by-trial isomerizations are Poisson distributed (Hecht, Schlaer, & Pirenne,
1942; Rodieck,
1998). The mean numbers of L, M, and S cone isomerizations under the standard illuminant for this experiment, taken across the image patches, were 439.8, 315.0, and 50.8 respectively for Modeled Experiment 1. For Modeled Experiment 2, the values were 325.6, 246.3, and 33.4.
Supplementary Table S1 provides the mean number of isomerizations for all of the illuminations for both modeled experiments.