  The electric field conjugation (EFC) algorithm has shown promise for removing
scattered starlight from high-contrast imaging measurements, both in numerical
simulations and laboratory experiments. To prepare for the deployment of EFC
using ground-based telescopes we investigate the response of EFC to unaccounted
for deviations from an ideal optical model. We explore the linear nature of the
algorithm by assessing its response to a range of inaccuracies in the optical
model generally present in real systems. We find that the algorithm is
particularly sensitive to unresponsive deformable mirror (DM) actuators,
misalignment of the Lyot stop, and misalignment of the focal plane mask.
Vibrations and DM registration appear to be less of a concern compared to
values expected at the telescope. We quantify how accurately one must model
these core coronagraph components to ensure successful EFC corrections. We
conclude that while the condition of the DM can limit contrast, EFC may still
be used to improve the sensitivity of high-contrast imaging observations. Our
results have informed the development of a full EFC implementation using the
Project 1640 coronagraph at Palomar observatory. While focused on a specific
instrument our results are applicable to the many coronagraphs that may be
interested in employing EFC.
