Best-fit SEDs for A1703-zD1 with constrained models (A_UV< 1.2) to two different sets of IRAC measurements (cf. Sect. 2.2). Red crosses show the synthesized fluxes in the photometric bands, black circles the observations. In both cases the resulting fit parameters are quite similar, which confirms the high specific SFR for this galaxy. The same is also obtained without the constraint on UV attenuation.