Left: equivalent width of the Hβ line for ⟨3D⟩ (solid line) and 1D (dashed) spectra as a function of log g for T_eff = 8000, 9000, 10 000, 11 000, and 12 000 K (values identified on the panel). Right: ratio of the Hϵ and Hβ equivalent widths as a function of T_eff for log g = 7.0, 7.5, 8.0, 8.5 and 9.0 (values identified on the panel). The line cores are not included in the equivalent width (see Eq. (4)).