Abstract

Goniospectrophotometry is the measurement of the spectral reflectance of a material using various bidirectional illumination and viewing angles. Goniospectrophotometric measurements are necessary for describing certain geometrical variations in the color of objects. Previously, it has been assumed that barium sulfate approximated a Lambertian diffuser. Many authors have shown that this assumption does not hold. Therefore, only goniospectrophotometers capable of making CIE recommended 0/45 or 45/0 measurements could be calibrated with existing standards to make measurements using nonstandard geometries.

© 1987 Optical Society of America