A face-on view of the Galaxy, with the Sun at the center. The right of each panel corresponds to b = 0°, and the Galactic center lies off the right edge of the plot. The left panel shows the initial iteration, without a spatially correlated prior on dust reddening density, while the right panel shows the final iteration, with a correlation length of 1.5 pc. We integrate the reddening from z = − 300 pc to +300 pc. As is evident from a comparison of the two panels, the correlated prior yields more isotropic cloud shapes, with less smearing along the line of sight. This effect is especially pronounced at nearby distances, where neighboring sightlines are more tightly coupled.