  The mass distribution of stellar mass black holes can provide important clues
to supernova modeling, but observationally it is still ill constrained.
Therefore it is of importance to make black hole mass measurements as accurate
as possible. The X-ray transient 1A 0620-00 is well studied, with a published
black hole mass of $6.61\pm0.25\,$M$_{\odot}$, based on an orbital inclination
$i$ of $51.0\pm0.9$ degrees. This was obtained by Cantrell et al. (2010), as an
average of independent fits to $V$-, $I$- and $H$-band light curves. In this
work we perform an independent check on the value of $i$ by re-analyzing
existing YALO/SMARTS $V$-, $I$- and $H$-band photometry, using different
modeling software and fitting strategy. Performing a fit to the three light
curves simultaneously, we obtain a value for $i$ of $54.1\pm1.1$ degrees,
resulting in a black hole mass of $5.86\pm0.24\,$M$_{\odot}$. Applying the same
model to the light curves individually, we obtain $58.2\pm1.9$, $53.6\pm1.6$
and $50.5\pm2.2$ degrees for $V$-, $I$- and $H$-band, respectively, where the
differences in best-fitting $i$ are caused by the contribution of the residual
accretion disc light in the three different bands. We conclude that the mass
determination of this black hole may still be subject to systematic effects
exceeding the statistical uncertainty. Obtaining more accurate masses would be
greatly helped by continuous phase-resolved spectroscopic observations
simultaneous with photometry.
