Mean clustering with its standard deviation of the Planck 2018 25 boxes using the median HOD. In red, ξ₀ is computed using Eq. (8) with a fixed LoS, and in blue using Eq. (3) with a varying midpoint LoS. In the latter case, in order to get a realistic clustering, we place the observer at the centre of the boxes, and cut a spherical full-sky footprint from z = 0.15 to z = 0.25. The bottom panel shows the residual using the cosmic variance of the (realistic) varying LoS.