The catadioptric projection can be modeled by an equivalent spherical projection. This idea is more versatile in the conformal geometric algebra, a modern framework for the projective space of hyper-spheres. In this framework we analyze diverse catadioptric mirrors, as a result the algebraic burden is reduced allowing the user to work in a more effective framework for the development of algorithms for omnidirectional vision. We present preliminary experiments useful for omnidirectional visually guided robotics.