Contours of constant χ^tot at the accretion disk plane (r, φ). The observer is situated at inclinations i = 30° (panel a), 60° (panel b), and 80° (panel c). The coordinates are in units of R_S. The polar angle φ is measured from the projection of the direction to the observer on the disk plane. The disk rotates in the counterclockwise direction. The innermost stable circular orbit at r = 3 is shown with a black circle. The dotted lines (wherever visible) show corresponding contours computed using the approximate formula for light bending (35).