Measured spectral resolution of the MILES SSP model spectra for both versions. To minimize template mismatch, we concentrated on SSP models with [M/H] =  [ − 1.31, − 0.71, − 0.4, + 0.0,0.22] and Age = [0.5,17] Gyr (160 models). The KPNO and S⁴N spectra were not included in this test because they do not contain enough representative stars to accurately reproduce the SSP models.