Saturation
Amount of color intensity comparing to the gray of of the same lightness. Saturation may vary from a neutral gray (no saturation) to a vivid (high saturation).

Saunderson Correction
Calculations that apply to reflectance measurements and correct for external and internal scattering of incident light at an interface.

Scattering
Diffusion or redirection of radiant energy encountering particles of a different refractive index.

Spectrophotometer
An instrument used for measuring the transmittance and reflectance of specimens as a function of wavelength.

Spectrophotometric Curve
A curve measured on a spectrophotometer resulting in a plot of relative reflectance versus wavelength.

Specular Reflectance Coefficient
A numerical term used to describe the value for the specular reflectance when used in the saunderson corrections.

Specular Excluded
Measurement of reflectance made in such a way that the specular reflectance of glossy samples is trapped and excluded from the measurement. Instrument calibration in this mode requires an optional change in calibration data.

Specular Included
The inclusive of spectral reflectance in the measured reflectance of a sample. This condition is normally used in the formulation program.

Specular Reflectance
Light striking a surface and is reflected or turned back at an angle equal to the angle of incident - the reflected light is the specular reflectance.

Standard Observer
A numerical description of the response of the normal human eye to color defined by CIE. Two sets of standard observers have been defined.

1) The 1931 - 2 Degree visual field - represents the human eye's view from a distance.
2) The 1964 - 10 Degree visual field - represents the human eye's view from arm's length.