Posterior distributions of the Hapke parameters for Apollo 12 soil sample 12001 at 550 nm. The left panel compares the retrieval using the restricted single-geometry subset (red) with that using the full multigeometry BUG dataset (blue). The values above the diagonal panels indicate the median and 16th–84th percentile credible intervals for the single-geometry retrieval. The right panel shows the multigeometry posterior on an expanded scale, with the corresponding median and 16th–84th percentile credible intervals. The much broader single-geometry posterior illustrates the strong parameter degeneracies introduced by limited angular sampling.