Illustration of the photometric data used in this work. Left panel: the m_F322W2 vs. m_F115W − m_F322W CMD, showing all detected stars. Likely SMC members and 47 Tucanae stars are marked with black and gray points, respectively. Right panel: the same CMD, restricted to stars in the field of the SMC. The black dashed line corresponds to the 50 % completeness limit for SMC stars in this dataset. The inset zooms in on the upper MS (20.4 < m_F322W2 < 23.8), where three isochrones with an age of 7 Gyr, distance modulus (m − M)₀ = 18.9, and reddening E(B − V) = 0.05 are overplotted. The blue and red lines correspond to metallicities of [Fe/H] = −2.2 and −0.5, while the green line indicates the best-fitting isochrone with [Fe/H] =−1.1.