The spectroscopic properties of elemental terbium, dysprosium, holmium, and erbium are investigated using first-principles calculations taking into account intra-atomic correlation effects. In order to describe the strongly localized f electrons together with the conduction bands, we have used the multiband Hubbard-I approximation to reproduce the multiplet features present in the experimental spectra. A comparison with available experimental data is made and the overall agreement is found to be good.