Age, mass, extinction, and metallicity derived for a sample of 10 000 artificial star clusters of true mass log ₁₀(M/M_⊙) = 4 , with σ = 0.03 mag of Gaussian photometric errors (block of panels a)), σ = 0.05 mag (block b)), and σ = 0.1 mag (block c)) using WFC3+ACS broad-band photometry. The true metallicity of the artificial clusters is indicated on the top of each column of panels. In each panel, the numbers indicate the percentage of the 10 000 clusters with derived parameter in the region between the dashed lines, which is centered on the true parameter value.