Comparing the optically thin formalism used in this work (blue) to the optically thick formalism (red) for A13 in IC 1613 (for which v_windturb is also a free parameter; top) and A15 in WLM (bottom). Also shown in the three rightmost plots are the best-fit (solid line), 1σ (dark shaded region), and 2σ (light shaded region) uncertainties obtained for Ṁ, v_∞, and f_cl for both runs.