Hi Kaleb, 

I am in Sequential mode. Can this be from aspheric terms of the first glass coupled with a large field angle?

Thanks for the answer,

Nadav

It's possible to generate this kind of confusion with a negative thickness. (Usually used for mirror spaces.) If that's the case, and you look at a complete 3D view, you will see the ray is reflected from a point on the surface which is not in the plane of the slice. (I also set  hide lens edges on the layout.)

Hi Nadav,

With my example, the issue is the negative thickness in the LDE. If you don't have a negative thickess, then my last post does not help.

However, it is possible to create non-physical lenses where a region of the lens seems to have a negative thickness. In the example below, the curvatures and thicknesses are such as to produce such a case. Note the appearance of something that looks like a reflection. If you use MNEG in the merit function you will find the edge thicknss of surface 1 is negative. This uses a spherical surface -- it would be even easier to create such a problem using aspherics. You can avoid this by including a minimum edge thickness operand MNEG in the merit function or by using an edge thickness solve on the offending surface.