Hi @anis2073,

The Object Space NA is independant of the object height. In the screenshot below, I have a single field at 0.0 as you described, and I changed the Object Space NA from 0.2 (blue rays) to 0.4 (green rays):

The only difference is the solid angle that subtend the rays. The cone of light described by the blue rays is more “narrow”. There is no notion of object height here.

For your second question, if you have a single field at 0.0. Then, it doesn’t matter what value of Hx and Hy you use in RAID. They will always be zero (your starting point). The Help File (F1) has a section Normalized Field Coordinates that you may be interested in.

Then, if you choose Px and Py randomly but in a way that:

Then, the random ray should be within the cone described by the NA. A larger Object Space NA means a larger system aperture stop, but RAID uses normalized coordinates in the interval -1, 1]. So, whatever the value of your Object Space NA, if you select Px and Py as described above, you will still sample your entire aperture (or cone).

Does that make sense? I hope I understood the question correctly.

Take care,

David