Trifid Nebula (photographed using a filter)

This is the Trifid Nebula photographed using a Optolong L’Extreme filter. The filter is a dual narrow-band filter, passing the Ha and OIII specturms. Since the Trifid Nebula is both an emission nebula (Ha emission) and a reflection nebula, the Ha spectrum was passed while the reflections from the nearby stars were filtered out.