The Leray transform L is studied on a family Mγ of unbounded hypersurfaces in two complex dimensions. For a large class of measures, we obtain necessary and sufficient conditions for the L 2 -boundedness of L, along with an exact spectral description of L * L. This yields both the norm and high-frequency norm of L, the latter giving an affirmative answer to an unbounded analogue of an open conjecture relating the essential norm of L to a projective invariant on a bounded hypersurface. L is also shown to play a central role in bridging the function theoretic and projective geometric notions of duality. Our work leads to the construction of projectively invariant Hardy spaces on the Mγ , along with the realization of their duals as invariant Hardy spaces on the dual hypersurfaces.