Histograms of the inferred azimuthal angle of the magnetic field vector, φ, when employing Eq. (6) in the synthesis of Stokes profiles. The original distribution δ(φ − π/8) is indicated by the vertical black arrow located at φ = 22.5°. The inferred histograms using S/R_quv, S/R_qu, and S/R_no−qu criteria are indicated by the solid, dashed, and dotted-dashed lines, respectively. Blue curves are obtained with a photon noise σ = 10^-3, whereas red ones correspond to σ = 3 × 10^-4.