Above: DEM of the 2010 Oct. 26 active region core. The numbers in parentheses are the ratios between predicted and observed intensities. The points are plotted at the temperature T_max, and at the theoretical vs. the observed intensity ratio multiplied by the DEM value. Below: corresponding AIA 94 Å count rates as a function of temperature and wavelength (the dashed curve is the normalised AIA effective area).