  The new operational mode of aperture masking interferometry has been added to
the CONICA camera which lies downstream of the Adaptive Optics (AO) corrected
focus provided by NAOS on the VLT-UT4 telescope. Masking has been shown to
deliver superior PSF calibration, rejection of atmospheric noise and robust
recovery of phase information through the use of closure phases. Over the
resolution range from about half to several resolution elements, masking
interferometry is presently unsurpassed in delivering high fidelity imaging and
direct detection of faint companions. Here we present results from
commissioning data using this powerful new operational mode, and discuss the
utility for masking in a variety of scientific contexts. Of particular interest
is the combination of the CONICA polarimetry capabilities together with SAM
mode operation, which has revealed structures never seen before in the
immediate circumstellar environments of dusty evolved stars.
