BP and RP response curves traced by the ratio between effective SPD computed from BP and RP spectra and source SPDs from ground-based observations. Top: data are plotted against wavelength; black triangles mark the position of Balmer lines. Bottom: residuals between data and the response models are plotted against pseudo-wavelengths. BP pseudo-wavelengths have been swapped left-to-right, while RP data are shifted by 60 samples. Blue- and red-filled triangles mark the position of BP and RP cut-of, f respectively, while blue and red open triangles show where the response drops to zero.