Long-period eclipsing binaries (variables) are a valuable source of data for calculating stellar masses. Such objects have a sufficient amount of both photometric and spectral data for determining their parameters and further analysis. We began a project to study long-period massive eclipsing binaries in order to determine their component masses and refine the mass-luminosity relation for stars of high and intermediate masses. We describe our project in general terms, focusing in more detail on the use of large photometric surveys as an important base in our research. We will talk about almost all avaliable large sky surveys, from which we collected all available photometric data on our objects and constructed light curves. We present the results of photometric data analysis for the objects we study using existing and specially constructed software packages. In particular we demonstrate several cases, where application of the surveys' data to our objects allows us to obtain new orbital period for eclipsing binaries. The paper is based on a talk presented at the astrophysical memorial seminar "Novelties in Understanding the Evolution of Binary Stars", dedicated to the 90th anniversary of Professor M.A. Svechnikov.