An apparatus for observing the appearance of a surface of a sample of semitransparent material, the apparatus comprising a light source for illuminating at least a region of interest of the surface of the sample from a predetermined direction and means for observing a response to the illumination of the region of interest, wherein the illuminated region comprises the region of interest and a region surrounding the region of interest. In this way the influence of emitted scattered light on the accuracy of the observation of the appearance of the sample is minimized.