Comparison of difference and ratio spectra at deep penumbral phase during ingress. (a) the Na I D lines at 5890 Å and 5896 Å, (b) the Mn I line at 5432.5 Å (with a close Fe I line at 5433 Å that does not show excess absorption) and, (c), the Ba II line at 5853.7 Å. The two middle spectra in each panel are the observed spectrum outside eclipse (red pluses) and the Ring-corrected spectrum inside eclipse (black line). The spectrum at unit intensity is the ratio, and the spectrum at zero intensity the difference, always with respect to the observed lunar spectrum outside eclipse. All eclipse spectra are from UT 3:50 during ingress. The x-axes are wavelength in Ångstroem.