Describes an optical measurement taken at an angle distinct from the specular (mirror-like) reflection angle. In colorimetry and surface evaluation, aspecular angles are used to assess how a finish, such as metallic or pearlescent paint, changes appearance depending on the viewing geometry.
Heard on the job
Check the L-star value at the 15-degree aspecular angle to see how the metallic flake pops near the gloss angle.