Results for 3C279. Lower panel: γγ absorption optical depth as a function of location of the emission region, R_em, for a fixed value of u_BLR as encountered by the emission region at the respective location (see the text), for several γ-ray photon energies. Upper panel: required luminosity of the BLR, according to the re-normalization of the local BLR emissivity (Equation (8)).