A system and method for identifying imperfections in a reflective surface. The reflective surface may be a metal coating on a sheet such as in a galvanization process. The system comprises a laser detector. The laser detector may be part of a triangulation unit. The laser detector takes readings corresponding to the angles of travel of diffuse light of a laser off of different portions of the reflective surface. Imperfections in the surface are identified based on variance in the readings. The method comprises detecting diffuse light of a laser beam off of different portions of the reflective surface, and identifying imperfections based on variances in the angles of travel of the diffuse light detected.