Comparison of the UV-phase signature of the same amount of aberration (here coma) for a non-saturated PSF (on the left) and a saturated one (on the right). The saturation primarily affects the higher spatial frequencies of the image, corresponding to the outermost parts of the Fourier plane. In the inner region of the saturated case (within the highlighted smaller circle), the Fourier-phase signature of the aberration is similar to its non-saturated counterpart.