This article describes the use of vignetting factors in modeling a system with fixed apertures. Vignetting factors can be used to determine the size and shape of the beam which passes through the system unobscured. These factors also provide a mechanism for efficient optimization of such systems.

This article is also available in Japanese.

Question: Why is the illumination of the stop surface referred to as "Apodization"? And What Does Apodization Do?

This article explains:

• What Ray-aiming is
• When it is needed and how to use it

This article includes examples using a sample lens file.

This article expains:

• What the Pupil Shift factor is
• How to specify the Pupil Shift Factor

This article includes a zipped file used as sample case.