“…horizontal size ratios of 0.5 or 2.0, depending on whether the surface is slanted left- or right-side back). For more distant and less slanted surfaces, which are more common in natural viewing ( Adams, Elder, Graf, Leyland, Lugtigheid, & Muryy, 2016 ; Backus, Banks, van Ee, & Crowell, 1999 ; Burge, McCann, & Geisler, 2016 ; Kim & Burge, 2018 ; Kim & Burge, 2020 ; Yang & Purves, 2003 ), the ratio tends to be substantially smaller. However, typical natural images have broadband 1/f spectra, and frequencies above the contrast detection threshold typically vary by a factor of 10 or more.…”