Top row: Line-of-sight magnetic field (B_LoS) at log ξ = −4 from the input model (a), compared with the weak-field estimates obtained from the original synthetic spectra (b), and from the same spectra after convolution with the CHROMIS spectral PSF with (c), and without noise (d). Bottom row: Logarithmic density plots comparing the input B_LoS with the weak-field results, for the case without the convolution with the PSF (e), and with the convolution with the PSF for the noiseless case (f) and the case with added noise (g). Dashed lines in the bottom row mark the identity line.