Differences in normalized residuals when correcting for uncertainty in the PSF (this example used the STARRED PSF model). Without this correction, the fitting of the point sources drives the fit while providing little information. Top left: Pixel uncertainty derived from the imaging data alone. Top right: Model-normalized residuals without PSF uncertainty correction. Bottom left: Pixel uncertainty including additional PSF uncertainty, estimated by fitting stars in the field (Sect. 4.1). Bottom right: Model-normalized residuals with PSF uncertainty correction. Residuals are more evenly distributed, encouraging the models to accurately describe the ring structure.