New Exit Pupil Drawing

Userlevel 7
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Hey Zemax team,

Sadly my license for OS does not include the new ‘draw entrance and exit pupils’ feature, but I saw a posting on LinkedIn that leads me to think it’s not correct.

I’m assuming that the red pupils are the off-axis pupil (and so sees the red rays). The pupils appear to me to be:

  • tilting the wrong way
  • not centered on the chief ray of the field point

I can’t play with the feature to satisfy myself. Could someone post this layout (its the double Gauss sample file) with ‘Draw Marginal and Chief Rays’ selected please?

  • Mark

26 replies

Userlevel 5
Badge +3

For engineers who are not that familiar with pupil aberration, here is a quick summary and I hope this helps you understand the above conversation.

The different fields work as “stops” by selecting rays that comes from the object (the stop).  When we reduce the size of the stop, we get the performance as on-axis field at different “pupil” coordinate. For rays that forms the on-axis fields, they become the chief rays from the viewpoint of pupil imaging system. For systems whose aberrations are not well corrected, it’s not surprising to have large position differences between the center field and the maximum field if the stop size is large enough, which is the difference between the ENPP and the one traced by the new feature.

The method used to determine the pupil position is similar to the paraxial ray tracing method from my viewpoint. Using rays from different orientation instead of tangential and sagittal is similar to the method we use in spot diagram.

(Feel free to correct me if I am wrong.)