Point source strong lensing cross-section as a function of lens axis ratio. Solid lines show the cross-section based on the lens event definition of Eq. (13) and dashed lines the cross-section based on the detection of four images (quad cross-section). Lines of different colours correspond to sources of different intrinsic magnitudes. The dashed blue line, corresponding to the brightest source magnitude, overlaps completely with the dashed orange line. The dashed purple line is zero: very faint sources cannot produce any detectable quads. The parameters of the lens density profile are f_DM = 0.5, γ_DM = 1.5, r_s = 10R_e, and θ_e = θ_Ein. The baryonic and dark matter components have the same ellipticity and direction of the major axis.