Comparison between estimated ages (left panel) and metallicities (right panel) using different upper limits on the age of the input SSPs. Blue, orange, and green dots represents the estimated ages using a 7, 8, and 10 Gyr age limit, respectively, marked in the left panel by the corresponding horizontal dotted lines. The magenta vertical line corresponds to the 6.5 Gyr age limit imposed in section 3. The gray horizontal line is the age of the Universe at z = 0.6 (≈7.8 Gyr). On both panels, the red line is the one-to-one relation, while the black dashed lines are the 1σ_Age and 1σ_[M/H] uncertainties.