The distances to open clusters as derived from main-sequence fitting. II. Construction of empirically calibrated isochrones

We continue our series of papers on open cluster distances by comparing multicolor photometry of single stars in the Hyades with theoretical isochrones constructed with various color-temperature relations. After verifying that the isochrone effective temperatures agree well with spectroscopically determined values, we argue that mismatches between the photometry and the theoretical colors likely arise from systematic errors in the color-temperature relations. We then describe a method for empirically correcting the isochrones to match the photometry and discuss the dependence of the isochrone luminosity on metallicity.