The Essential Macleod Core is the minimum configuration and contains all the normal design and analysis tools. It considers individual coatings, of as many layers as required, and any number of such coatings on any number of surfaces in an assembly, provided that the surfaces are reasonably parallel. The multiply-reflected beams between the various surfaces may be incoherently summed in the calculation or may be considered to walk out of the system. This permits, for example, stray light calculations. The media between the surfaces may be of any kind, even filter glasses.

Performance Calculations
Calculations in the Core include reflectance, transmittance, phase shifts where meaningful, dispersive parameters such as Group Delay Dispersion, the ellipsometric parameters, together with derivatives in terms of wavelength, up to the third order, where relevant. All of these can be derived in terms of wavelength, frequency, angle of incidence, polarization and thickness of a chosen layer. The effect of Lambertian or Gaussian cones of illumination, including polarization, or of scanning bandwidth as in a spectrometer, can be included. Provided the substrate is rigid, the effect on performance of temperature changes can be assessed.

Color Calculations
Calculable color parameters include all the common color spaces, color rendering index, purity, dominant wavelength, correlated color temperature. Color patches give an idea of the quality of a color. Plots include chromaticity diagrams, uniform color space, hue and chroma correlates and user-defined plots. A selection of sources, including many standard illuminants together with the CIE 1931 and 1964 color matching functions are supplied but the user may define others as necessary. Color parameters can be calculated for imported transmittance or reflectance data as a function of wavelength. They may also be specified as targets for refinement.

Design and Analysis Tools
Tools include admittance diagrams, electric field distribution, Herpin equivalents, absorptance distribution, stress, optical scattering, performance envelopes, non-polarizing edge filter design, and induced transmission.

Extraction Tools
Optical constants for both thin films and thick substrates can be derived from spectroscopic data.

Reverse Engineering
A reverse engineering tool analyses performance of coatings from deposition cycles that somehow failed to achieve the required performance.

Tolerancing
Random errors may be introduced in layer thickness in a simple tool to assess the tolerances for production while other tools give a sense of layer sensitivity. [Note: A more advanced tool that actually models coating production, is the Simulator Enhancement, described separately.]

Refinement and Synthesis
Five refinement tools and two synthesis tools are provided. Layers may be locked or linked (layer linking is a more advanced form of grouping where noncontiguous layers may be associated) and packing density may be included in the Simplex form of refinement. Many different constraints may be introduced, including total thicknesses of selected materials. Refinement and synthesis of multiple coatings is also possible. Context permits the use of agile materials.

Plots and Tables
Normal plots, active plots (where the effect of parameter variations can immediately be seen) and three-dimensional plots are all available. Normal plots are adaptive, that is the interval varies according to the detail in the results. This faithfully traces even tight fringes without any effort on the part of the user. User-defined templates allow plot styles to be changed instantly so that, for example, the same plot, but with different styles, can be copied and pasted first into a Microsoft Power Point slide, next into a document in Microsoft Word, and, finally, into a News Letter in Microsoft Publisher.

Reports
A powerful report generator uses user-defined templates to generate automatically multi-page reports that may include many different aspect of designs, performance, materials, and other details.

Importing and Exporting
The clipboard is fully supported for importing and exporting data and is the recommended method for sharing data with other applications. Many other techniques are available. There are also special facilities for certain designated applications for optical design including ZEMAX, Code V, FRED, VirtualLab.

Units
Units can be anything that the user wishes provided only that they are proportional to SI units. Default wavelength and frequency are in nm and cm-1 respectively but, as supplied, the program can be quickly switched to m and cm-1, Å and eV, or nm and GHz. Other units can be readily defined by the user.

Operation
Operation is virtually intuitive. For example to combine two plots, drag one over the other. To add the plot of a table column, drag the column onto the plot. Right click in a plot to edit its details. Toolbars can be customized by the user and placed anywhere in the application window. Icons can be altered or added.

Limits
There are virtually no limits to parameters such as the number of layers in a design and the number of wavelength points in a material except the inherent capacity of the computer and the patience of the user.