  The quantum Cram\'er-Rao bound for the joint estimation of the centroid and
the separation between two incoherent point sources cannot be saturated. As
such, the optimal measurements for extracting maximal information about both at
the same time are not known. In this work, we ascertain these optimal
measurements for an arbitrary point spread function, in the most relevant
regime of a small separation between the sources. Our measurement can be
adjusted within a set of tradeoffs, allowing more information to be extracted
from the separation or the centroid while ensuring that the total information
is the maximum possible.
