Reading this excellent answer about field of view, focal length and sensor size a new question came to mind.
From the drawn diagrams it is clearly visible that for the same focal length an increase in sensor size means an increase in field of view. If, following the diagram, an (imaginary) sensor of 100mm wide would be used with a 50mm lens the field of view would be 90 deg.
However, I have the feeling that something will be limiting the actual field of view. What determines the maximum sensor size a lens can project onto and still increase field of view, i.e. without showing a black border? Is it the size of lens element closest to the sensor? The size of the frontal element? Some other factor?