Modelling Δn_γ(z) on true galaxy catalogue using our emulator. The detections are divided into six slices based on their true redshifts. The black line shows our correction (Eq. (11)) of each slice on shear calibration that ignores redshift dependence. The grey area around the black line presents the 1-σ uncertainty of the galaxy population model. The correction decomposes into the effect of secondary galaxies n_γ, blend (dashed blue curves) and the falsely adopted self-response $n_{\gamma ,\mathrm{blend}}^{\mathrm{const}}$ from ‘constant-shear’ calibration (dashed red curves).