Masks for the OMC-3 field. The levels correspond to areas with low emission (Q=−1), extended cloud (Q=0), filament (Q=1), ridge (Q=2), bright parts of the ridge (Q=3), FIR point sources and highsurface brightness areas affected by local heating (Q=4), and MIR point sources (Q=5). The small dots correspond to the NIR star-like (cyan) and potentially extended (blue) sources that are the basis of the NIR extinction map (Meingast et al. 2016).