Investigating the effect of achromatic level and illumination/observation geometry on visually perceived specular gloss

In the present study, attempt were made to investigate the visual perception of specular gloss of a series of achromatic samples. To this end, seven achromatic physical scales of specular gloss each consisting 10 samples were prepared using lithographically printed black, white and five in between gray papers. The samples were visually assessed and subsequently quantified in terms of a visually uniform color constant lightness scale, by a panel of 14 observers in an especially designed unidirectional light chamber at three illumination/observation geometries, namely 20˚/20˚, 60˚/60˚ and 85˚/85˚. It was found that the visual perception of specular gloss is influenced by the achromatic level of the sample, as well as the assessment geometry.