IMPLICIT:  The implicit format for the RAYLIST.TXT file consists of two numbers on each line: one for the Px and one for the Py normalized pupil coordinates.  The syntax is as follows:

Px Py

For example, in a rotationally symmetric system, the two meridional marginal rays are defined in the RAYLIST.TXT file by:

These specified rays are traced at each defined field and wavelength in the settings of the respective layout plot.

Take the “Double Gauss 28 degree field.ZMX” sample file (ZEMAX/Samples/Sequential/Objectives directory) as an example.  The Double Gauss design includes three fields (0, 10, and 14 degrees) and three wavelengths (F, d, and C wavelengths representing the visible spectrum).

If we choose to display the two defined meridional rays at the primary wavelength (wavelength 2) and from All fields, a total of 6 rays will be drawn.  That is, 2 marginal rays * 1 wavelength * 3 fields.  Remember to select List as the “Ray Pattern!”