This picture appeared in National Geographic and according to the snippet, it was captured with Samsung NX10 and 18-55mm f/2.8 lens. Samsung currently has only a 18-55 f/3.5-5.6 lens in their lineup. Samsung NX10 roadmap for 2011 mentions only a new 16mm /f2.8 and a 60mm f/2.8 lenses. Maybe a typo?
Via dpreview