Peter Stetson has already derived precise (and accurate) B and V photometry
for about 40 stars within our field - so these will be included by default
and can be used to set photometric zero-points. However we will need to
observe standard fields with 
photometry on the standard system as
well in order to derive a proper photometric calibration which is independent
of Peter Stetsons. It will only be necessary
to do this photometric calibration for the DFOSC observations as we can
transform the CTIO and Siding Spring observations to the DFOSC system.
We should observe such standard fields on nights when the weather is suspected to be photometric. The observer should evaluate this - although of course you will never know until afterwards whether it actually was photometric. Therefore, obtain observations of standard stars on at least 3 different nights.
When observing the standard fields, take care that they are well distributed
in airmass, such that extinction coefficients can be determined. The
observations of NGC
6397 should give the 
extinction coefficient.
Note, that there will be periods for the D1.54m telescope when the object is inaccesible due to pointing restrictions. If the weather is photometric calibration observations of std. stars can be obtained during such periods.
There is an extensive list of UBVRI standard stars available at:
http://cadcwww.hia.nrc.ca/standards/ continue with the link: stetson in the upper left cornor.
This gives a long list of fields suitable for CCD observations. It is from this list the fields selected here has been chosen. These fields are listed in Appendix A and comprise a mixture of Landolt (1992, AJ, .......) fields, globular and open cluster fields that Peter Stetson has transformed carefully to the standard system. Most of the Landolt fields contain 3-5 bright stars, but many fainter ones which Peter Stetson has put on the standard system, by collecting other peoples observations of these fields and reduced them in a homogeneous manner.