PSF reconstruction errors (left column) and biases (right column). From top to bottom, plots for the size and two ellipticity components, e₁ and e₂, are shown. In each panel, the values are given as a function of the binary fraction in the stellar population considered and for the three different PSF shapes described in Table 2. The solid lines represent the predicted values using the formalism in Sect. 3. The latter is valid for N_⋆ → ∞ while the simulations used in this figure are for N_⋆ = 40 stars with apparent magnitude in the range 18 ≤ i(AB) ≤ 19.