Index: trunk/Mars/mhist/MHCamEvent.cc
===================================================================
--- trunk/Mars/mhist/MHCamEvent.cc	(revision 13381)
+++ trunk/Mars/mhist/MHCamEvent.cc	(revision 13387)
@@ -54,4 +54,5 @@
 // ----------------
 //  + fNameSub
+//  + fIsRatio
 //
 /////////////////////////////////////////////////////////////////////////////
@@ -96,5 +97,5 @@
 MHCamEvent::MHCamEvent(const char *name, const char *title)
 : fSum(NULL), fErr(NULL), fEvt(NULL), fSub(0), fType(0), fErrorSpread(kTRUE), fErrorRelative(kFALSE),
-fThreshold(0), fUseThreshold(0)
+fThreshold(0), fUseThreshold(0), fIsRatio(false)
 {
     Init(name, title);
@@ -109,5 +110,5 @@
 MHCamEvent::MHCamEvent(Int_t type, const char *name, const char *title)
 : fSum(NULL), fErr(NULL), fEvt(NULL), fSub(0), fType(type), fErrorSpread(kTRUE), fErrorRelative(kFALSE),
-fThreshold(0), fUseThreshold(0)
+fThreshold(0), fUseThreshold(0), fIsRatio(false)
 {
     Init(name, title);
@@ -226,5 +227,10 @@
     case kNoBound:
         if (fSub)
-            fSum->AddCamDifference(*evt, *fSub, fType);
+        {
+            if (fIsRatio)
+                fSum->AddCamRatio(*evt, *fSub, fType, w);
+            else
+                fSum->AddCamDifference(*evt, *fSub, fType, w);
+        }
         else
             fSum->AddCamContent(*evt, fType, w);
Index: trunk/Mars/mhist/MHCamEvent.h
===================================================================
--- trunk/Mars/mhist/MHCamEvent.h	(revision 13381)
+++ trunk/Mars/mhist/MHCamEvent.h	(revision 13387)
@@ -32,4 +32,6 @@
     Char_t fUseThreshold;  // Use a threshold? Which direction has it?
 
+    Bool_t fIsRatio;       // If NameSub is set: Use Ratio or difference
+
     Int_t fNumReInit;      //!
 
@@ -51,5 +53,5 @@
 
     void SetNameEvt(const TString name)  { fNameEvt = name; }
-    void SetNameSub(const TString name)  { fNameSub = name; }
+    void SetNameSub(const TString name, Bool_t ratio=kFALSE)  { fNameSub = name; fIsRatio = ratio;  }
     void SetNameGeom(const TString name) { fNameGeom = name; }
     void SetType(Int_t type) { fType = type; }