A plano-concave lens is a lens with one side being flat and the other side being concave. It is characterized by being thin in the center and thick at the edges, and can make parallel light rays ...

One existing type, called a Fresnel zone plate (FZP), uses concentric ridges to focus light, rather than a thick, curved surface. While this method does create a lightweight and compact lens ...

While the patent lists a number of examples of different lenses, one of the examples suggests that the lens would be a fisheye without the second set of optics and a normal ultra-wide lens without ...