Correlation between WISE and IRAS. In the top panel we plot the WISE 12 μm flux versus the IRAS 12 μm flux; in the bottom panel we show the ratio of the IRAS 12 μm flux to the WISE 12 μm flux, as a percentage. The dotted line in both panels shows a one to one relationship. Errors are the 1σ photometric uncertainties. There is a correlation between the two fluxes over four orders of magnitude, although there is significant scatter in the relationship. This scatter is likely due in large part to the difficulty of IRAS photometric measurements. We have included only H II regions that are not saturated in the WISE 12 μm band.