We present the composite luminosity function ( hereafter LF ) of galaxies for 80 Abell clusters studied in our survey of the Northern Hemisphere , using DPOSS data in the framework of the CRoNaRio collaboration .
Our determination of the LF has been computed with very high accuracy thanks to the use of homogeneous data both for the clusters and the control fields and to a local estimate of the background , which takes into account the presence of large-scale structures and of foreground clusters and groups .
The global composite LF is quite flat down to M ^ { * } +5 and it has a slope \alpha \sim - 1.0 \pm 0.2 with minor variations from blue to red filters , and M ^ { * } \sim - 21.9 , -22.0 , -22.3 mag ( H _ { 0 } = 50 km s ^ { -1 } Mpc ^ { -1 } ) in g,r and i filters , respectively ( errors are detailed in the text ) .
We find a significant difference between rich and poor clusters supporting the existence of an LF ’ s dependence on the environment .