Color map of the systematic percent error of the covering fraction as a function of the resolution and S/N. The synthetic spectra are created with R < 120 km s⁻¹ combine a theoretical stellar continuum spectra with R(S99) = 120 km s⁻¹ and absorption lines of spectral resolution R. The covering fraction is recovered to within 5% of the estimated parameter for all observations within the dark blue region.