  The UBVRI broad band photometric system is widely used in CCD astronomy.
There are a lot of sets of standard stars for this photometric system, the
Landolt's and Stetson's catalogues being the most precise and reliable. Another
photometric system, recently considerably spread in CCD observations is ugriz,
which originates from the Sloan Digital Sky Survey (SDSS) and has now many
variations based on its 5 broad-band filters. One of the photometric systems
based on it is The Panoramic Survey Telescope and Rapid Response System
(Pan-STARRS). In this paper we compare the BVRI magnitudes in the Stetson
catalogue of standard stars with the magnitudes of the corresponding stars in
the Pan-STARRS1 (PS1) grizyw catalogue. Transformations between these two
systems are presented and discussed. An algorithm for data reduction and
calibration is developed and its functionality is demonstrated in the magnitude
determination of an asteroid.
