  The long exposure times of the HST Ultra-Deep Field plus the use of an
empirically derived position-dependent PSF, have enabled us to measure a
cardioid/displacement distortion map coefficient as well as improving upon the
sextupole map coefficient. We confirmed that curved background galaxies are
clumped on the same angular scale as found in the HST Deep Field North. The new
cardioid/displacement map coefficient is strongly correlated to a product of
the sextupole and quadrupole coefficients. One would expect to see such a
correlation from fits to background galaxies with quadrupole and sextupole
moments. Events that depart from this correlation are expected to arise from
map coefficient changes due to lensing, and several galaxy subsets selected
using this criteria are indeed clumped.
