Maps of the magnetic field strength in the region of interest from the Bifrost simulation (left panels), from the mME approximation (central panels), and from the WFA (right panels); and for the Mg I b2 line (top) and for the Ca II 854.2 nm (bottom). The maps in the left panels are taken at the estimated optical depths according to the mME inversion results (log τ₅₀₀ = −3.0 for Mg I b2 and log τ₅₀₀ = −5.0 for Ca II).