Upper panel: reconstructed transmission spectrum of GJ3470b. The U_spec and F972N20 data points are extracted from our LBC light curves (blue circles), the g′R_cI_cJ points from Fukui et al. (2013) (green circles), and the 4.5  μm point from Demory et al. (2013) (red circle). The model plotted with a dark green line is scaled from a Howe & Burrows (2012) model computed for a 10-M_⊕ cloud-free, haze-free planet with T_eq = 700 K and a pure water (H₂O) atmosphere. The open squares represent the model points integrated over the instrumental passbands. Second panel: same as above, but with a cloud-free, haze-free, metal-poor atmosphere dominated by H and He, computed by the same authors (orange line). Abundances are scaled from the solar ones (Z = 0.3 × Z_⊙). Third panel: same as above, but adding the contribution of a scattering haze from Tholin particles at 1 μbar. Lower panel: instrumental passbands employed for each data point.