Median retrieved spectra for the HST and Spitzer observations of HD 209458b (left) and WASP-39b (right) for a lower wavelength data cutoff of ﹩{\lambda }_{\min }﹩. Shown are ﹩{\lambda }_{\min }﹩ values from 0.3 μm (dark blue) to 1.1 μm (dark red) in intervals of 0.1 μm. The observed, multi-instrument transmission spectrum is overlaid (black diamonds). The retrieved spectrum is plotted at R = 100 for clarity.