The full three-dimensional dispersion of the $\pi$-bands of graphite measured with angle-resolved photoemission spectroscopy (ARPES) and compared to first-principles calculations. The figures a) and b) are cuts through the H point along the k$_y$ direction, whereas the figures c) and d) are equi-energy contours of the photoemission intensity around the KH axis. The red lines represent the density functional theory (LDA) band structure that underestimates the slope of the bands and the trigonal warping effect. Including electron-electron correlation on the level of the GW approximation (blue lines) renormalizes the Fermi velocity by more than 17%, and yields remarkable improvement with the experiments (A. Grüneis, C. Attaccalite et al. Phys. Rev. Lett. 100, 037601 (2008) )