Best derivation of the photometric redshift of the foreground lensing galaxy, using the Le PHARE code (Ilbert et al. 2006; Arnouts et al. 1999). The filled triangle shows the HST F110W flux density and the filled circles represent the GTC measurements (see text). The WISE data (open circles) have not been included in the fit. The curve shows the best fit model, a Sb spiral template (Polletta et al. 2007; Ilbert et al. 2009). The inset displays the distribution of χ² as a function of redshift; the dotted horizontal lines correspond to the 1, 2, 3σ levels, defined as . The best photometric redshift for the foreground galaxy is where the errors are 3σ.