[O III] luminosities measured in the SALT spectra, after dust attenuation correction and flux calibration, compared with luminosities of mid-IR lines ([Ne III], [Ne V], and [O IV], from top to bottom on the left) and with bolometric luminosities inferred in different ways (from SED fitting, [Ne V] lines, and [O IV] lines, from top to bottom on the right). Symbols and colors of the observations are the same as in Fig. 2. Solid lines show the relations in Eqs. (1)–(3), while dotted lines are those obtained considering the [O III] luminosities from Malkan et al. (2017).