Upper panels: zenith angle ζ′ the photon reaching the observer makes to the local normal in the fluid frame as a function of the azimuth for disk inclinations i = 30° (panel a), 60° (b), and 80° (c) and different emission radii r = 3 (black solid line), 5 (red dashed), 15 (green dot-dashed), and 50 (blue dotted). Lower panels: difference between ζ′ computed using the analytical formula (35) for light bending and the one using exact formula.