# Understanding stereographic projection in fish-eye lenses

Can I imagine a stereographic projection as looking on a reflecting sphere from an infinite distance?

Or could I say that it's the same as a perspective projection but the imaging plane is a sphere which is then parallel projected onto a plane?

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Stereographic projection and conformity is explained here and it is award-winningly neat. –  user13838 Nov 5 '11 at 2:17