Spectra of the luminosity xl_x (upper panels), PD (middle panels) and PA (bottom panels) for different inclinations i = 30° (left), 60° (middle), and 80° (right column) and BH spin a = −1 (pink lines), 0 (red), 0.5 (orange), 0.8 (green), and 0.94 (blue). The solid lines correspond to the results obtained with the approximate analytical formulae (ARTPOL), while the dashed lines correspond to the exact numerical integration of the geodesics (ARCMANCER). The accretion disk extends from r_ISCO to r_out = 3000 for each case. Narrow panels show the difference between the results given by the two methods. The black dotted lines denote the results for a Newtonian disk from Loktev et al. (2022).