Binary fraction estimation in the SMC field. Left panel: m_F322W2 vs. m_F115W − m_F322W2 CMD of SMC stars. Region A (green solid line) includes MS stars and binaries with primary masses between 0.61 and 0.81 M_⊙. Region B (green-shaded area) contains binaries with q > 0.6. MS and binary stars are indicated with black points and red crosses, respectively, while the remaining stars are colored in gray. Central panel: Same as the left panel but for artificial and field stars. Azure star symbols represent stars simulated with the TRILEGAL code (Girardi et al. 2005) within a Galactic field with the same area and coordinates as the one investigated in this work. Right panel: Best-fit simulated CMD. Colors and symbols follow the same scheme as in the left and central panels.