Ray-tracing and radiative transfer calculation of 2D recoiling black-hole simulation. Left column: as viewed at an observer inclination angle of θ_obs = 0.1°. Right column: viewed at an observer inclination angle of θ_obs = 60°. From top row to bottom row, as viewed at t = 0, 10 000, 15 000, and 20 000 M. The colour scale is logarithmic in the total intensity, I, from each pixel (arbitrary units).