RR Lyrae stars have long been important objects of study in astronomy. The purpose of this study was to compare photometric light curves constructed using DAOPHOT of 21 select known RR Lyrae stars to the light curves of these same stars constructed using ISIS. The globular cluster M3 was chosen for this study because it has a large number of variables both inside the core and outside the core to compare with each other. Outside the core of the globular cluster M3, we found that the light curves produced by DAOPHOT and those produced by ISIS were comparable. However, inside the core we found that ISIS produced superior light curves and results. These superior light curves could allow better analysis of stars located inside the cores of globular clusters. This could eventually lead us to a better understanding of how globular clusters may be formed and what properties they possess.