Interferometric continuum maps of OMC-2 FIR 4 with natural (top) and uniform weighting (bottom). White contours represent the 2-mm continuum emission obtained with the PdBI, while black contours, as well as the background colour scale, correspond to the 3-mm continuum emission seen with the NMA (S08). Contours for both the PdBI and NMA maps start at 3σ and increase by steps of 3σ. The bottom-left ellipses represent the respective beam sizes. The white open circles mark the primary beam FWHM for the PdBI observations. The black crosses mark the NMA 3-mm cores as reported in Table 4 of S08.