Spectrophotometric light curves for the transit of WASP-17b, produced with bins of 100 Å width after the common mode correction (CMC), shifted for clarity. The solid black line for each plot is the best-fit transit systematics model and the grey areas are the 1σ representations of those solutions. The dashed lines represent transit models derived with the optimised parameters of each light curve. The central wavelength of each channel used to produce the light curve is given next to each plot. The light curves excluded from transmission spectroscopy have been included here for completeness.