Na D ratio spectra during penumbral eclipse (black) compared to out-of-eclipse (blue; top five spectra). Each spectrum is labeled with its UT at start of exposure. Bottom spectrum: single out-of-eclipse spectrum. The deeper penumbral phases are reconstructed with excess Na D absorption while the shallow penumbral phases (UT 7:03–7:10) are not. We also note that the strong excess absorption during the deep penumbral ingress at UT 3:50 could not have been seen with CD VI (which includes the O₂ A-band, the neutral K line, and the Ca IRT) because CD IV was used instead. The residual excess emissions during shallow penumbral eclipse are due to the improper Ring corrections for these phases (see text). Wavelengths are in Ångstroem and a vertical offset of 0.1 is applied.