Ca IIλ854.2 nm line averaged over regions of different vertical magnetic fields. The layout is similar to Fig. 3a but shows a larger wavelength range, which also includes the continuum. The black line shows the observed data from the Hamburg FTS atlas. The dashed orange line indicates the line profile of the IM computation averaged over regions that have |B_z|_avg < 60 G, and the solid orange line the IM computation averaged over regions that have |B_z|_avg ≥ 60 G (see Sect. 3.4). For simplicity, we show only the data for the IM computation. The insets show zoomed-in views of the continuum and the line core; the latter is similar to Fig. 3a.