Hello there friends from the Zemax community,

I have a freeform surface which was obtained via an external numerical routine. 

My numerical routine provides me with the surface sag information (x and y coordinates and the associated surface height).

I have tried importing this surface into a sequential mode system via a grid sag object. 

However, I can observe that the surface profile changes depending on the distance set between my previous surface and the imported freeform surface.

I would expect the surface to have the same extension always, isnt it? 

Any comment or feedback will be highly appreciated!