create a dummy surface before the first lens surface and assign it a radius similar to the radius of the first lens surface and you should ge the rays from 100 half field of view display properly. i think you system design is a bit similar to the example file, Wide angle lens 200 degree field.zmx in ZEMAX. If so I think there is a dummy surface already. Just change radius of the dummy surface shall put you right. pP<8zTLn
`FHudSK
What you see in your second diagram is not TIR but the result od sequential ray tracing!! : )
