Visual representation of the PSF-matching procedure. All cutouts are 2″ per side. (a) Empirical PSF for the F275W filter in the mosaic frame, with the total flux normalised to unity. (b) Target PSF, i.e. the normalised F444W PSF from the MegaScience data release. (c) Convolution kernel as derived by PYPHER. (d) Original PSF (a) convolved with the kernel (c). (e) Residuals of the convolved PSF compared to the target, i.e. (d)−(b).