  As the James Webb Space Telescope (JWST) has become fully operational,
early-release data are now available to begin building the tools and
calibrations for precision point-source photometry and astrometry in crowded
cluster environments. Here, we present our independent reduction of NIRCam
imaging of the metal-poor globular cluster M92, which were collected under
Director's Discretionary Early Release Science programme ERS-1334. We derived
empirical models of the Point Spread Function (PSF) for filters F090W, F150W,
F277W, and F444W, and find that these PSFs: (i) are generally under-sampled
(FWHM~2 pixel) in F150W and F444W and severely under-sampled (FWHM~1 pixel) in
F090W and F277W; (ii) have significant variation across the field of view, up
to ~15-20 %; and (iii) have temporal variations of ~3-4 % across multi-epoch
exposures. We deployed our PSFs to determine the photometric precision of
NIRCam for stars in the crowded, central regions of M92, measured to be at the
~0.01 mag level. We use these data to construct the first JWST colour-magnitude
diagrams of a globular cluster. Employing existing stellar models, we find that
the data reach almost the bottom of the M92 main sequence (~0.1 M$_{\odot}$),
and reveal 24 white dwarf candidate members of M92 in the brightest portion of
the white dwarf cooling sequence. The latter are confirmed through a
cross-match with archival HST UV and optical data. We also detect the presence
of multiple stellar populations along the low-mass main sequence of M92.
