Abstract: The invention relates to a measuring system for the characterization of materials i.e. determination of the optical properties thereof such as brightness, surface aspect, transparency, color (pigments and colorants) and color effects (pearly or metallic). According to the invention, said system comprises an optical sample illumination device (110, 103, 108), an optical device (100) for measuring the light reflected by the sample for treatment by a spectral decomposition device, and a mechanical support structure (300) for the optical measuring device placed above the sample. The optical measuring device (101, 102) comprises a lens formed by several simultaneous measuring points at several angles of the sample.