Use of Paraxial surface in NSC mode for Image simulation

  • 12 August 2021
  • 1 reply


I have to simulate a NSC component and some image analysis in non-sequential mode.
Kindly help on how to use paraxial surfaces in NSC mode and how to set up the parameters (focal length, exit pupil location etc.)




Best answer by David 14 August 2021, 21:04

View original

1 reply

Userlevel 6
Badge +4

Hi Naresh,

The paraxial lens in non-sequential is similar to the paraxial lens in sequential mode. The x and y focal lengths are parameters of the object and entered in the the non-sequential component editor as part of the object definition. There is a thorough description of the paraxial lens in the help system in both sequential and non-sequential modes.

For a system consisting of a single paraxial lens the entrance and exit pupils coincide with the lens. For a more complex system it is not so simple. The exit pupil is the image of the aperture stop as seen from the image side. The chief ray crosses the optical axis at the position of the exit pupil. The semi-diameter of the exit pupil is determined by the height of a marginal ray at that position. These rays may be real or virtual. (You will need to back trace to see them if the pupil is virtual.)

Non-sequential mode has no real understanding of the aperture stop or chief and marginal rays. In sequential mode the aperture stop is defined, and OpticStudio has ray aiming capabilities that allow it to produce and analyze chief and marginal rays. This means you can measure and target pupil positions. There are merit function operands that do so.If you need to control the entrance and exit pupils of a system it is best to work in sequential mode. Then, if you need to do stray light analysis or radiometry, convert the design to non-sequential for that purpose.

Kind regards,