Fits to simulated observations with a 10-TMPL model. The observations consist of 160, 250, 350, and 500 μm intensities for a single Τ = 15 Κ MBB function (upper frames) or a sum of 13 Κ and 17 Κ components of equal optical depth (red circles in frames b and e). Frames a and d show random realisations of the combinations of weights W that result in less than 5% errors for all four predicted intensities (curves in frames b and e). The frames c and f show the distributions of the τ values predicted by those fits. The true optical depth is τ(250 μm) = 0.01.