Illustration of the effect of the telescope PSF on the data. The FOV is divided in two halves for a monochromatic image at Δλ = 91 mÅ from line center in Stokes I (left) and V (right). The lower half shows the observations, without applying the PSF compensation. The upper half shows the synthetic image from the inversion, including the PSF compensation. This inversion has been performed assuming 50% sparsity.