Synthetic spectra based on Model 1 (high metallicity, purple), Model 2 (low metallicity and cloudy, green) and Model 3 (haze, black) based on the WASP-117b spectrum reduced with the nominal pipeline (left panels), and the CASCADE pipeline (right panels). Colored areas show the 1σ envelope for the solutions for each model. Solid lines in gray, yellow, and light pink present the best fit for Model 1, Model 2, and Model 3, respectively. The spectra are shown for the wavelength range 0.3–0.9 μm (upper panels) and 1–15 μm (lower panels). In addition, a hypothetical data point with 50 ppm accuracy is shown for guidance.