a) Example of the application of to the best-fitting synthetic SED (light blue) obtained with Starlight for a SDSS-DR7 (York et al. 2000) spectrum (orange) for three t_cut values: 30 Myr (blue), 0.5 Gyr (green), and 5 Gyr (red). The transmission curves of the five SDSS filters u, g, r, i, and z are depicted with shaded areas. Panels b) and c) show, respectively, the luminosity (x_j) and mass (μ_j) contribution (%) of individual SSPs (1 ...j) to the best-fitting population vector. The light-gray vertical lines in the upper-right panel show the ages available in the SSP library for four metallicities (between 0.05 and 0.95 Z_⊙) and vertical arrows depict the applied t_cut values. From panels b) and c) it is apparent that, according to the best-fitting population vector, SSPs younger than 30 Myr contribute less than 2% of ℳ_⋆ but nearly 35% of the observed intensity at the normalization wavelength of 4020 Å. As a result, suppression of these young SSPs results in a significant dimming by 0.56, 0.27, 0.22, and 0.19 mag in the SDSS u, g, r, and i-bands, respectively.