The effect of measuring geometry on computer color matching

The debate over the best optical geometry for color measurement dates back to the development of the first recording reflectance spectrophotometer. It is hypothesized that a bidirectional geometry conforms best to the procedure used to inspect colored surface samples visually. This hypothesis was tested using two spectrophotometers of nearly identical design, one utilizing d/8 geometry and the other utilizing 0/45 geometry. The results indicate that bidirectional geometry may be superior to integrating‐sphere geometry when matching standards with varying gloss. The bidirectional measurements are quite sensitive to the size of the source and the detector‐aperture half angle.