A variety of compact nebulae was observed to retrieve the morphology in the light of infrared recombination lines ([Siv] at λ = 10.5μm and [Neii] at λ = 12.8μm) using TIMMI, ESO's focal reducer for the thermal infrared at the 3.6m telescope (Käufl et al. 1994). Compared to optical images in some cases striking differences are found. It should be noted that the dust in nearly all PNs is transparent at λ ≈ 10μm even if there is substantial extinction in the optical (λ ≤ 1μm). As compared to space based infrared platforms (IRAS and ISO) our observations have lower sensitivity but sub-arcsec spatial resolution. In some cases the data allow also to assess the relative spatial distribution of dust and gas.