Hi Almax,

I’m not entirely sure what you’d like to do, but in Sequential mode, you can setup apertures on your surfaces. To do so, you can double-click on the surface of interest, which will open its properties, and go to the Aperture tab. You can then choose Aperture Type: Circular Aperture and adjust the Minimum Radius, Maximum Radius, Aperture X-Decenter, and Aperture Y-Decenter.

In Non-Sequential mode, you should be able to tilt the assembly you described. It is a good idea to overlap the standard surface with a cylinder volume (nested rule) to create the aperture as this will give among the fastest results with raytracing. The trick is perhaps to use the Ref Object column and a dummy (Null) object. I’m showing an example below:

By referencing the cylinder to the surface and the surface to the null object you can apply a tilt by simply changing the value of the Tilt About… columns.

In case my example is not clear, the reason the cylinder works as an aperture is because it is made of air, and when two objects intersect, it is the properties of the latest (greater object number) in the non-sequential data editor that prevail.

Let me know if this helps.

Take care,

David

Hi David,

first of all thank you for your reply.

your example is clear and solved my problem. Just to clarify an aspect, once tilted the mirror, how can I change the angle of the image plane correspondingly? I tried to add a coordinate break before the non sequential component but it does not work.

thank you again

Hi Almax,

My pleasure. You may want to have a look at this thread.

Let me know if it doesn’t solve your issue.

Take care,

David

Hi David,

With reference again to your examples, I need to ask you some more clarifications:

• Sequential scheme: it is clear, everything works in reflection but I cannot make rays propagate through the aperture. I am trying to propagate reflected (-z direction) rays for 750mm but I need also a propagation of 1000mm in the +z direction. I cannot achieve the latter. I guess I am not allowed to do this in a sequential scheme.

• Non sequential example. I defined a non sequential object composed by a flat mirror with an aperture facing a tilted concave (spherical) mirror. The latter reflects rays coming from the aperture again on the flat mirror. Then I assign a value to the Exit Loc Z parameter in the Lens Data, relative to the NSC, to propagate rays towards the image plane. 

I add a dummy and a coordinate break surface just after the NSC and before the IMAGE one.

If the image plane is after the curved mirror, the conjugate point is correctly identified, but if the image is formed on a plane located in between the flat and the curved mirror, ray propagation is stopped and I cannot evaluate it anymore. 

Is there a way to overcome this problem?

Thank you again