Color Measurement on Metalized Substrates
Fig. 1: 45°/0° spectrophotometers use directed geometry. (Double click illustrations to enlarge.)
Fig. 2: Spherical instruments use diffuse geometry.
Fig. 3: A 45° instrument may yield values that indicate that the shiny sample is darker and more saturated.
Fig. 4: Using the specular-included mode, a sphere spectrophotometer will yield similar measurement results, regardless of the reflectance of the surface.
Fig. 5: Using the specular-excluded mode, a sphere spectrophotometer will yield measurements that take into account the reflectance of a surface and produce results that are pretty similar to a 45° instrument, which is usually the condition closest to the visual assessment.
Fig. 6: With mirror-like surfaces, a 45° instrument will essentially be “blind” since almost none of the light is available to be measured by the sensor.