We present color-magnitude diagrams of five Galactic globular clusters and one Galactic open cluster spanning a wide range of metallicity ( -2.1 \lesssim [ Fe/H ] \lesssim + 0.3 ) , as observed in the F606W ( broad V ) and F814W ( I ) bands with the Advanced Camera for Surveys ( ACS ) on the Hubble Space Telescope .
These clusters are part of two large ACS programs measuring the star formation history in the Andromeda halo , tidal stream , and outer disk .
In these programs , the clusters serve as empirical isochrones and as calibrators for the transformation of theoretical isochrones to the ACS bandpasses .
To make these data more accessible to the community , for each cluster , we provide a ridge line tracing the stars on the main sequence , subgiant branch , and red giant branch , plus the locus of stars on the horizontal branch .
In addition , we provide the transformation of the Victoria-Regina isochrones to the ACS bandpasses .