Index: trunk/ppMerge/src/ppMergeCombine.c
===================================================================
--- trunk/ppMerge/src/ppMergeCombine.c	(revision 9376)
+++ trunk/ppMerge/src/ppMergeCombine.c	(revision 9463)
@@ -258,4 +258,12 @@
                 }
 
+                // Set the dark time for the output image, since we normalised
+                if (options->darktime) {
+                    psMetadataItem *darkItem = psMetadataLookup(cell->concepts, "CELL.DARKTIME");
+                    darkItem->data.F32 = 1.0;
+                    psMetadataItem *expItem = psMetadataLookup(cell->concepts, "CELL.EXPOSURE");
+                    expItem->data.F32 = 1.0;
+                }
+
                 memCheck();
 #endif