Modulated flux (normalized to the maximum), Doppler factor (1 + z)^-4 and solid angle (arbitrary units) in the rest coordinate frame of an emitting clump in a circular orbit around a Schwarzschild BH for different radii and inclinations angles. The continuous black lines are calculated with the exact equations, while the dashed red lines are calculated with the approximate equations. All quantities are plotted as a function of the arrival phase at the observer. In the left panels a self-eclipse of the spot is apparent.