Column density maps for a selected small region in Cloud I. Frame a) shows the true column density of the model cloud and the frames b) and c) the errors in the estimates of Method A and Method B, respectively (N(A) − N_true and N(B) − N_true). Frame d) shows the column density errors when estimates are calculated using data with 18.3″ resolution at all wavelengths, N(18.3) − N_true. The frames e–f) show the errors of Method A and Method B relative to the estimates from 18.3″ resolution data. The range of data values is given at the bottom of each frame.