Sample image of a hotspot at different points in the orbit. Top row: image of the hotspot before, during, and after a strong lensing event. Top-right plot: image averaged over the whole orbit. Lower left panel: lightcurve produced over several orbits, lower right panel: motion of the centroid of emission. This figure was produced with a hotspot in a circular orbit at R = 5M around a black hole with spin a = 0.9. The spin axis of the black hole is inclined i = 15° from the observer’s line of sight and the relative inclination between the spin axis and the orbital plane is θ = 50.54°.