Fitting photometric models to the average reflectance in a 5 × 5 pixel sized box centered on Cerealia Facula in XMO4 and RC3 clear filter images, with ι, ϵ < 70° (n = 69). The insets zooms in on the smallest phase angles. Panel A: Akimov phase function with Lambert/Lommel-Seeliger disk function. Panel B: as panel A, showing the equigonal albedo. The boundary between the two data sets (XMO4 and RC3) is indicated. The best-fit model is drawn in red, while the best-fit model for Ceres average (Fig. 13), scaled to match the former at α = 0°, is drawn in green. Panle C: best-fit Hapke model, which has . Panel D: best-fit Hapke model for (fixed).