Vulcan's Anvil. The blue open cluster at about 7 o'clock is NGC 3572 in SW Carina. The strongly sculptural nebulosity above it is strong in H-alpha (green), shows moderate SII emission at the strongest shock fronts (red), and has a very weak general glow in OIII (blue). It reminds us of a giant anvil being struck very hard indeed, breaking off bits of molten metal, which drip down. One such chunk, about 10 o'clock from dead centre, has taken the shape of a bat flying with upstretched wings to the right. Note the unidentified isolated blob of H-alpha in the middle of the cluster. It is virtually impossible to get any detail on this object in straight RGB. Exposure 12 hrs (4 hours on each channel). STL-11000M on 20" PlaneWave on MI-750.