Index: trunk/psModules/src/objects/pmSourcePhotometry.c
===================================================================
--- trunk/psModules/src/objects/pmSourcePhotometry.c	(revision 18554)
+++ trunk/psModules/src/objects/pmSourcePhotometry.c	(revision 19905)
@@ -3,6 +3,6 @@
  *  @author EAM, IfA; GLG, MHPCC
  *
- *  @version $Revision: 1.43 $ $Name: not supported by cvs2svn $
- *  @date $Date: 2008-07-15 20:25:00 $
+ *  @version $Revision: 1.44 $ $Name: not supported by cvs2svn $
+ *  @date $Date: 2008-10-06 13:03:40 $
  *
  *  Copyright 2004 Maui High Performance Computing Center, University of Hawaii
@@ -230,6 +230,5 @@
     }
 
-    // measure the weight of included pixels
-    // XXX is this supposed to use the weight or the flux?
+    // measure the contribution of included pixels
     if (mode & PM_SOURCE_PHOT_WEIGHT) {
         pmSourcePixelWeight (&source->pixWeight, model, source->pixels, source->maskObj, maskVal);
@@ -379,7 +378,8 @@
     NY = image->numRows;
 
-    // measure modelSum and validSum
-    // XXX this does not work for sources near the edge: we need to measure for
-    // a full square region
+    // measure modelSum and validSum.  this function is applied to a sources' subimage.  the
+    // value of DX is chosen (see above) to cover the full possible size of the subimage if it
+    // were not by an edge; ie, if the source is cut in half by an image edge, we correctly
+    // count the virtual pixels off the edge in normalizing the value of the pixWeight
     for (int ix = -DX; ix < DX + 1; ix++) {
         int mx = ix + dX;