DMC: Digital multi-coated filter, greatly reduces the appearance of lens flare and ghosting caused by reflections BAF: Black Almite Frame, a black matte aluminum satin finish almite frame which reduces reflections BRG: Black Rimmed Glass, reduces the chance of light reflecting off the edge Low profile frame, ultra thin frames to help avoid vignetting on super wide angle lenses Kef: Knurling edge frame, these filters are equipped with a straight knurling edge for non-slip, easy attachment and removal