Contours of the convergence at z_s = 3. The member galaxies used in the model are also shown in black. The value of the convergence is indicated for some contours. We mark the value of κ = 0.5 with a thicker contour, which indicates the approximate position of the cluster critical curve at higher redshift. The value for the convergence in the last contour near the centre of the plot is κ = 1.06.