Comparison of the three $A_{K_{\mathrm{s}}}$ (int) values estimated from three MIR datasets with the $A_{K_{\mathrm{s}}}$ (int) values from surrounding stars. Left panel: $A_{K_{\mathrm{s}}}$ (int) values from the MSX data are plotted vs. the median $A_{K_{\mathrm{s}}}$ (int) estimated with surrounding stars by Messineo et al. (2005). Middle panel: $A_{K_{\mathrm{s}}}$ (int) values from the WISE data are plotted vs. the median $A_{K_{\mathrm{s}}}$ (int) from Messineo et al. (2005). Right panel: $A_{K_{\mathrm{s}}}$ (int) values from the GLIMPSE data are plotted versus the median $A_{K_{\mathrm{s}}}$ (int) from Messineo et al. (2005). The dashed lines are fits to the data points (see text); the red dotted lines are the equity lines.