  The density of states for the three-dimensional Ising model is calculated
with high-precision from multicanonical simulations. This allows us to estimate
the leading partition function zeros for lattice sizes up to L=32. Combining
previous statistics for smaller lattice sizes, we have evaluated the correction
to scaling and the critical exponent $\nu$ through out an analysis of a
multi-parameter fit and of Bulirsch-Stoer (BST) extrapolation algorithm. The
performance of the BST algorithm is also explored in case of the 2D Ising
model, where the exact partition function zeros are known.
