Effect of the type of illumination on perceived blackness of automotive finishes

Abstract

The blackness perception of six black automotive finishes was evaluated under three different illumination conditions: unidirectional illumination, diffuse illumination and light booth condition. The metallic black panels with approximately the same appearance attributes, specular gloss, distinctness of image and orange peel, were selected to minimize the effect of total appearance factors on perceived blackness. Fourteen non-expert observers (5 males and 9 females) assessed the black panels while their normal color vision was examined by the Ishihara test. The pair comparison method was applied to rank the metallic black panels based on their perceived blackness. The results showed that under the diffuse illumination condition, a good correlation was observed between the lightness attribute of metallic black panels and their visual scales, where a decrease of the L* value leads to an increase of perceived blackness. In addition, observers assessed the darkest and the most neutral panel as the blackest sample under the three applied illumination conditions.