Cumulative distribution along the vertical coordinate of the VISTA tile for sources with different classifications on the VDFS catalog: stellar in both J and Z (solid red line), extended in both J and Z (dot-dashed black line), stellar in J and extended in Z (long-dashed magenta line), stellar in Z and extended in J (short-dashed blue line). A flat spatial distribution corresponds to a line at 45 degrees (dotted line). The hatched region indicates the location of the disk of NGC 253, where the surface brightness is too high to measure individual sources and number counts are heavily affected by crowding effects.