  The Multi-Unit Spectroscopic Explorer (MUSE) has enabled a renaissance of the
planetary nebula luminosity function (PNLF) as a standard candle. In the case
of NGC 300, we learned that the precise spectrophotometry of MUSE was crucial
to obtain an accurate PNLF distance. We present the advantage of the integral
field spectrograph compared to the slit spectrograph in delivering precise
spectrophotometry by simulating a slit observation on integral field
spectroscopy data. We also discuss the possible systematic shift in measuring
the PNLF distance using the least-square method, especially when the PNLF
cutoff is affected by small number statistics.
