Comment 2 for bug 696668

Regarding optimisation of FoV, the problem with 'v' reducing to zero only happens with very narrow panoramas .

Think about the panorama as segment of the 'sphere'. With a narrow field of view this segment is very similar to a flat surface, and the photos will fit whatever 'v' you give them.

With a scene with a large field of view (>90) the segment is significantly curved and it isn't possible to get a 'better' fit by simply reducing 'v' for the photos.