Marginalised probability distributions of dust parameters for an ellipsoidal cloud model. In the radiative transfer modelling (see text) the cloud is viewed either along its minor axis (red lines) or its major axis (purple lines). For both cases, the optical depth along the line of sight is τ_J = 6 and the dashed lines show the input values used in the computations. The stars indicate the projected positions of the χ² minima and the black contours show the 1σ and 2σ of the projections. The greyscale map corresponds to the red lines.