Index: trunk/ppStack/src/ppStack.h
===================================================================
--- trunk/ppStack/src/ppStack.h	(revision 20995)
+++ trunk/ppStack/src/ppStack.h	(revision 21092)
@@ -154,8 +154,8 @@
 /// Calculate transparency differences between images
 ///
-/// Corrects the source PSF photometry to a common system
-bool ppStackSourcesTransparency(const psArray *sourceLists, // Sources for each input
-                                const pmFPAview *view, // View to readout
-                                const pmConfig *config // Configuration
+/// Corrects the source PSF photometry to a common system.  Return the sum of the exposure times.
+float ppStackSourcesTransparency(const psArray *sourceLists, // Sources for each input
+                                 const pmFPAview *view, // View to readout
+                                 const pmConfig *config // Configuration
     );