Deviations from the fitted modified black body law in the case of the MHD model. The plot shows the relative deviations for 5% of the highest (blue symbols) and 5% of the lowest column density (black symbols with larger error bars) pixels. The error bars correspond to noise per pixel for the general noise level N = 0.1. The dotted line shows relative deviations between a ν^2.1 dependence and the actual opacity in the employed dust model.