Comparison of 250 µm optical depth estimates from MBB fits and RT models. The upper frames show the results of single-temperature MBB fits with β = 1.8 (frame a) and β = 2.0 (frame b). The second row shows the ratios between the MBB fit with a Gaussian temperature distribution and the corresponding single-temperature fit from the first row, with contours drawn at levels of ±5%. The bottom row shows the τ ratios for two RT models (FWHM = 0.5 pc, A_V = 1^mag) and the single-temperature MBB fits from above. The dust models are COM in frame e and CMM in frame f.