Open the Double Gauss 28 degree field.zmx sample file in ZEMAX/Samples/Sequential/Objectives folder.

Lets suppose that this file represents a camera lens in which the stop semi-diameter is known to be exactly 10 lens units. The system aperture can be then be defined as “float by stop size", thus the semi-diameter value in the Lens Data Editor determine the size of the system aperture; a proper choice when the size of the stop is known.

The system aperture type can be defined under System >General>Apertures

Set the system aperture to “float by stop size”.



The stop semi-diameter can be manually set to 10 lens unit in the Lens Data Editor.