Upper assembly: observed brightness-temperature Dopplergrams for the three lines in the format of Fig. 4. Each panel displays the normalized Dopplergram subtraction , with bright implying blueshift (updraft) for spectral absorption features and redshift (downdraft) for spectral emission features. The grayscale is defined so that D = 0 is represented by the same gray in all panels while the ranges are adapted per panel for largest contrast. The separations from line center Δλ, specified in kms^-1 in each panel, are the same as in Fig. 4. Lower assembly: corresponding results from the smeared simulation. The Δλ values are the same as in Figs. 5 and 6.