Enlarged section (≈1 Mm  ×  1 Mm) of the continuum intensity image (Figure 2) showing the part of the atmosphere where the 3D NLTE calculation was performed. The yellow line and the five yellow dots (a–e) indicate selected positions used in the text for further analysis. The yellow dots were drawn larger (2  ×  2) than in the actual image for better visibility. The black contours indicate the boundary of the magnetic element corresponding roughly to B_z(z = 0) = 1200 G.