The unfolded differential energy spectrum of B3 2247+381 observed by MAGIC. The black data points refer to the measured spectrum, while the grey dashed points have been corrected for the attenuation of the EBL. The thick black and dashed grey lines are power-law fits to the respective data points (fit results are given in the text). The dashed band corresponds to the statistical error of the fit to the measured spectrum, while the white band surrounding it is the sum of the statistical and systematic errors of the fit.