Example of the slit/spectrum distribution over a full VIMOS pointing, showing the disposition of the four quadrants and the “cross” among them. The circles identify the targets selected by the SPOC optimisation algorithm. The elongated blue rectangles reproduce the “shadow” of the 2D spectrum that will result from each target in the final spectroscopic exposure. The thin red lines show the boundary of the actual spectroscopic mask, traced pointing-by-pointing through an automatic detection algorithm that follows the borders of the illuminated area (see Guzzo et al. 2014, for details)