A methodfor upgrading a projective reconstruction to metric is presented. The reconstruction is first transformed by considering cheirality so that the convex hull of the set of camera projection centres is the same as in the metric counterpart. The method then proceeds iteratively and starting fiom such a reconstruction is a necessary condition for many iterative calibration algorithms to converge. The results show that in practice it is also most often sufficient, provided that the-minimised objectivefunction is a geometrically meaningful quantity. The method has been found extretnely reliable for both large and small reconstructions in a large number of experiments on real data. When subjected to the common degeneracy of little or no rotation between the views, the method still yields a vety reasonable member of thefamily of possible solutions. Furthermore, the method is vetyfast and therefore suitable for the purpose of viewing reconstructions.