Lenses designed designed for digital cameras, where the rays emerging from the rear of the lens remain nearly normal (perpendicular) to the sensor surface, tend to have reduced light falloff. For aesthetic purposes I generally recommend undercorrecting the image, i.e., using a larger Lens ...
Since the ratio of refractive indices of the waveguide and refractive layer 99 is smaller than to air, the TIR circle is larger than at the air boundary. The four conjugate images propagating along first waveguide 10 are all outside both circles 107 and 109, so that the images propagate ...