Hi Michele,

I would take a look at this forum post: 

Specifically, you could place an object with a table coating on it in front of your detector. The table coating will limit rays of a certain angle from passing through the object and onto the detector. Then you can optimize for maximum flux on your detector. 

-Kaleb

Dear Kaleb,

Sorry if I bother you again, I'm just wondering if you have a specific object in mind for the task: I tried to used a Standard surface, which seemed the simplest choice, but I noticed that one cannot apply coating to it.

Thank you again,

Michele

Hi Michele,

In non-sequeantial mode you cannot coat 2D objects, such as the Standard Surface. If you would like to use a Table Coating, then you will need to use a real 3D object, for example a Rectangular Volume, instead. You may find more info about how to add coatings to non-sequential objects in this knowledgebase article.

Alternatively, if you are using a Detector Rectangle or a Detector Color, you can use the X/Y Angle Min/Max parameters of the detector object to limit the angular sensitivity range:

The minimum and maximum x and y direction angles are in degrees. These settings are used to control the sensitivity of the detector to rays incident upon the detector at an angle when displaying radiant intensity or radiance in angle space. The default setting is -90.0 degrees to +90.0 degrees in both x and y directions, which allows display of angle data for all rays striking the detector. If the angular range is set to cover a subset of the possible incident angles, rays that strike the detector at angles outside the defined range are ignored ONLY for radiant


intensity and radiance in angle space displays.

Best,

Csilla

You might also want to look into using NSC 'Filter Strings' to select only those rays of interest to trace.

Depending on which version / manual you have, the page number might vary, but search for 'The Filter String' under 'The Setup Tab.'