Consider a simple Standard Lens object. This has three faces (faces are counted starting from zero):

For any object, the manual describes the faces of that object, and the coat/scatter tab lists the "friendly names" of the faces. Once you select a face, you can select three different ways for rays to interact with it:

If you choose "object default" then the reflectivity of the face is defined by the refractive material of the glass entered in the Non-Sequential Component Editor, the refractive material on the other side of the face, any thin-film coating on the face (described later), and the wavelength, polarization and incident angle of the ray that hits the face. Scattering functions can also be applied.

If you choose "Reflective", the face behaves as if the optical material was "MIRROR". Rays approaching the face from either side are reflected. Coating and scattering functions can be applied as normal.

If you choose "Absorbing" then any ray incident on the face is terminated. No coating or scattering function can be applied.

In the rest of this article, it is assumed that "Object Default" is selected.

Once a face is selected, any coating from the currently loaded coating file can be applied to that face using the "coating" drop-down box. ZEMAX incorporates a complete polarization ray tracing and analysis capability. Any input polarization state may be defined. ZEMAX accounts for transmission, reflection, absorption, polarization state, diattenuation, and retardance.

Coatings may be composed of arbitrary layers of arbitrary material, each defined with a complex index of refraction, with full dispersion modeling in the coating materials. Substrates may be glass, metallic, or user defined. Full details are given in the manual, chapter "Polarization Analysis", subsection "Defining Coatings in ZEMAX". ZEMAX can also import coating definitions directly from The Essential Macleod, Film Star and other thin-film coating design packages. ZEMAX automatically reverses the coating layer order if faces go from air to glass then glass to air, so the same coating may be applied on many faces without the need to define “mirror image” coatings.

If the original coating prescription is not available, a TABLE coating of performance data versus wavelength and angle may be used, or an IDEAL coating which simply gives reflection and transmission for all rays at all angles and wavelengths may be used.

With the coating data in place, ZEMAX computes the diattenuation, phase, retardance, reflection, transmission, or absorption of any coating as a function of input polarization, wavelength and angle.

Next, a surface scattering function can be applied. The scattering functions available include Lambertian, Gaussian, ABG, and user-defined.

For example, the front face of the lens is likely to be well polished, and may have a quarter-wave MgF₂ coating on it. This coating is called "AR" in the default coating catalog which ships with ZEMAX. To place this coating on Face 1, the front face:

Face 0, which is the side face, is likely to be unpolished and uncoated, and so could be entered like so: