Example of continuum intensity images (left column), mask of the magnetic regions identified in the data (middle column, white (black) shows the magnetic (quiet) component) and stray-light fraction (right column) derived from the SIR inversion of the IBIS Fe I 617.3 nm line data, at seven stages of the pore formation at a) 13:58 UT, b) 14:26 UT, c) 15:08 UT, d) 16:08 UT, e) 18:44 UT, f) 19:29 UT, and g) 20:35 UT. North is at the top; west is to the right. The small black squares in the continuum intensity images show the 20 positions considered for the comparison between observed and inverted profiles in Figs. A.2–A.8. The contour line in the panels of the middle and right columns shows the location of the evolving structure singled out in the continuum data, as specified in Fig. 3.