Use the Aberration Evaluation () derived values node to compute a list of Zernike coefficients for Zernike polynomials that correspond to various types of monochromatic aberration that arise when electromagnetic rays are focused by a system of lenses and mirrors. An Intersection Point 3D data set (see Intersection Point 2D and Intersection Point 3D) pointing to a Ray (Data Set) data set must be used. The data set must point to an instance of the Geometrical Optics interface in which the optical path length is computed. To add this node, right-click the Derived Values node and choose Aberration Evaluation from the More Derived Values menu

In addition, in the Settings window for the Intersection Point 3D data set, Hemisphere must be selected from the Surface type list. The Center of the hemisphere corresponds to the focus and the Axis direction points from the focus toward the center of the exit pupil in the focusing system.

The optical path difference among all rays that pass through the exit pupil is computed. Then a linear least-squares fit is used to express the optical path difference as a linear combination of a standard set of orthogonal polynomials on the unit circle, called Zernike polynomials. The polynomials are scaled by the coefficients that are computed by the least-squares fit, called the Zernike coefficients.

Select an option from the Maximum polynomial order list: 2, 3, 4, or 5 (the default).