  We present griz observations for the clusters M92, M13 and NGC 6791 and gr
photometry for M71, Be 29 and NGC 7789. In addition we present new membership
identifications for all these clusters, which have been observed
spectroscopically as calibrators for the SDSS/SEGUE survey; this paper focuses
in particular on the red giant branch stars in the clusters. In a number of
cases, these giants were too bright to be observed in the normal SDSS survey
operations, and we describe the procedure used to obtain spectra for these
stars. For M71, also present a new variable reddening map and a new fiducial
for the gr giant branch. For NGC 7789, we derived a transformation from Teff to
g-r for giants of near solar abundance, using IRFM Teff measures of stars with
good ugriz and 2MASS photometry and SEGUE spectra. The result of our analysis
is a robust list of known cluster members with correctly dereddened and (if
needed) transformed gr photometry for crucial calibration efforts for SDSS and
SEGUE.
