Distribution of global luminosity density D8 around galaxies versus distance. The black line with error bars shows the median value of global luminosity density D8 at a given distance. We note that the logarithmic scale enhances low values of density and the associated errors. We mark several rich superclusters where D8 values are high. CB denotes the Corona Borealis supercluster, A2142 marks the supercluster SCL A2142, and SGW1 and SGW2 mark the locations of the two richest superclusters in the Sloan Great Wall. The dark red line shows the distance limit 270 h⁻¹ Mpc used to define our final sample of galaxies.