Index: /trunk/MagicSoft/Mars/mcalib/MCalibrationChargePix.cc
===================================================================
--- /trunk/MagicSoft/Mars/mcalib/MCalibrationChargePix.cc	(revision 3274)
+++ /trunk/MagicSoft/Mars/mcalib/MCalibrationChargePix.cc	(revision 3275)
@@ -742,5 +742,8 @@
   // Calculate the conversion factor between PHOTONS and FADC counts
   //
-  fMeanConversionFFactorMethod         =  fPheFFactorMethod / GetMeanCharge() / fAverageQE;
+  // Nphot = Nphe / avQE
+  // conv  = Nphot / FADC counts
+  //
+  fMeanConversionFFactorMethod         =  fPheFFactorMethod / fAverageQE / GetMeanCharge();
 
   if (fMeanConversionFFactorMethod < 0.)