Flow chart of the method used to produce the 3D masks and to compute V_max. The key points are shown in red and the main path followed by the method is indicated in blue. All the steps related to the determination of the bright pixels are shown in grey. The steps related to the computation of the S/N of each source are indicated in green. The numbered labels in light blue refer to the bullet points in Appendix D that briefly sum up all the differnt steps of this figure.