Vertical cuts in B_∥ (left column) and B_⊥ (right column). The cuts have been taken along the long axis of ROI 1, averaging over the central 5 pixels across that axis. Top row: non-LTE-inferred field. Bottom row: MHS field. The non-LTE and MHS panels have been clipped to the same values according the colour bars at the top of the figure. The dashed lines indicate the heights corresponding to log τ₅₀₀ = −5.1 (upper line) and −4.1 (lower line) in the upper panels and the equivalent column mass in the MHS model in the lower panels. The lower panels also show the field over a larger z-height range than in the top row.