1. Apparatus designed to examine a surface ( 9 ), comprising a polarization analyser element or analyser ( 14 ) placed in the path of a light beam ( 17 ) reflected by the said surface, characterized in that it comprises a means for taking digital images ( 13 ) placed in the path of the beam reflected by the said surface downstream of the analyser, and a processing unit ( 15 ) capable of calculating the brightness and the intensity of a plurality of points of the said surface from pixels of at least two images of the said surface.