2D maps of the values for A_Veff and R_Veff for a face-on simulated spiral (left) and elliptical galaxy (right). The galaxy dust density has been normalized so that the total optical depth along the R axis is τ_VR = 5. Each point corresponds to a single pixel with a resolution of 25 pc, color-coded according to their galactocentric distance. Binned medians are shown in red, with error-bars defined by the bin standard deviation. The dashed black line reflects the true R_V of the medium, with the dotted black lines defining a 10% deviation from this value. Only pixels with A_Veff > 0 and R_Veff > 0 are shown.