Abstract: Homogeneous and accurate stellar parameters are vital for a number of purposes in stellar and Galactic astronomy. While different photometric and spectroscopic methods exist to translate stellar observables into physical parameters, each one of those comes with its pros and cons. Photometry provides a relatively cheap -yet powerful- way to gauge into those uncertainties. I briefly review different photometric methods and highlight the importance of correctly translate magnitudes into physical fluxes. Further, when photometric stellar parameters are coupled with asteroseismology, new and interesting twists become possible. I present results from the ongoing SAGA survey (Strömgren for Asteroseismology and Galactic Archaeology), which currently includes photometry for over 20,000 stars in the Kepler field, 1000 of which are red giants with seismic information. Coupling Strömgren metallicities with the Infrared Flux Method, and the unique asteroseismic determination of stellar masses and radii, powerful new diagnostics for Galactic studies are obtained. Using this sample I discuss the age and metallicity gradients in the Galactic disc and the impact of our results for understanding some of the processes relevant in its formation.