Hi Nadav,

The Tilt About X and Tilt About Y cells act upon the local coordinate system of the object, so if you have both an X and Y tilt, you need to consider the final compounded tilt to get the actual angle the rotated local coordinate makes in global space. 

The following Knowledgebase Article provides an in-depth discussion of rotation angles in OpticStudio:

https://optics.ansys.com/hc/en-us/articles/42661777200403-Rotation-Matrix-and-Tilt-About-X-Y-Z-in-OpticStudio

Hi MichaelH,

Thanks for the answer.

I tried also “convert to nsc group” and i got error of 0.1% with small fields. At larger field (30,30) it gets worse- error of 10%. Does it make sense?

B,R

Nadav

Asking it in another way: Let’s say we have field x=30deg,y=20deg in sequantial mode, how can I transform it to Non sequantial mode? Is there is no quick method?

EDIT:

I am uploading another file, where there is a very large discrepancy between two sources and the detector.

Please advice.

Thanks,

Nadav

Hi Nadav,

Going back to your original question, if you want to know the angle of a ray after reflection, diffraction, etc., you should look at the direction cosines of the ray and the normal vector of the object the ray hit.  You can calculate the angle of incidence using either multiple NSRA operands or you can use a ZRD with the Ray Database Viewer.  To get the AOI, you simply take the dot product of the direction cosines with the normal vector:

Since OpticStudio always normalizes both the direction cosine and the normal vectors, the denominator is always 1; also, if the Detector Rectangle is pointing in the z-direction (no rotation on the Detector Rectangle), then the n_x and n_y portions of the normal vector become zero and the AOI simplifies to:

This can easily be calculated in the MFE for a single ray for both sources:

If you use a Coordinate Break in sequential mode with both a (45°, 45°) and a (30°, 45°) tilt (in 2 different configurations), you will get the same AOI when you use the RAID operand:

So there is agreement between sequential and non-sequential modes in terms of rotation angles; note that in sequential mode, the angles are negative because we need to make the Image Surface the GCRS so the common reference between both configurations is the image plane, but this doesn’t affect the AOI calculation.

In your scenario, you said you want the angle after refraction or reflection, so you’ll need the segment after the ray interacts with the object (NSC will provide the direction cosine before refraction or reflection).  The following KBA talks about calculating the angle of incidence in non-sequential mode:

Is an angle of incidence report available in the Ray Database Viewer? | Zemax Community

As for the values being reported in the Detector Viewer, these are the projected solid angles on the Detector Rectangle, not the propagation angles of the rays.  The following KBA talks about how the angular data is calculated for the Detector Viewer Radiance in Angle Space.

Hi Michael,

Thanks for the detailed answer.

I don’t see the KBA. Is it the” Is an angle of incidence report available in the Ray Database Viewer? | Zemax Community”?

Regarding the final part of the answer, how can there be projected solid angles when we are dealing with plane-waves?

I should write it earlier but I have complicated system made from refracting and diffractive elements when I use fields from a sequntial systmen( lets say x=30, y=20 field), and I need to make sure that I exit the system with same field(s). What would be the best and efficient way to do it?

B.R

Nadav

Hey Nadav,

Sorry, here is the second KBA that I was mentioning:

How is radiant intensity defined? | Zemax Community