[dima55]

I would love for us to move past the idea that non-pinhole projections have "distortion", and we should strive to remove this "distortion" by reprojecting stuff to pinhole models. In practice, ALL projections distort straight lines and/or shapes and/or sizes, so if you use the pinhole projection everywhere, your images look like crap (see iphone wide-lens camera output for instance). Most of the normal non-pinhole projection functions work fine for wide lenses, while behaving like a pinhole lens with long lenses: https://en.wikipedia.org/wiki/Fisheye_lens#Mapping_function