Comparison between the likelihood contours in the Ω_m0-σ₈ plane for two different types of bias. Left panel: no bias due to ellipticity calibration was assumed, but the source-redshift estimate was assumed to be off by Δz_s = 0.05 and Δz_s = −0.1, as indicated by the line type. The right panel is the same as the bottom-left panel in Fig. 2. A wide survey was assumed for both panels. The comparison shows that, for a wide survey with narrow PSF, the calibration bias can be comparable or larger than a realistic bias due to an erroneous source redshift.