Impact of PSF model errors. Multiplicative (left panel) and additive (right panel) shear bias differences obtained employing a Euclid/VIS pixel scale of $0\stackrel{″}{.}1$ (test Ic with PSF stack). For the analysis shown here we have employed a star stack as PSF model for the convolution and a model stack for the deconvolution, as described in Sect. 5.5. The data points show the bias obtained from the fit with the error bars indicating 1σ uncertainties employing N_gal ≃ 18.3 × 10⁶ galaxies for each S/N value.