Index: trunk/psModules/src/camera/pmFPAMosaic.c
===================================================================
--- trunk/psModules/src/camera/pmFPAMosaic.c	(revision 38457)
+++ trunk/psModules/src/camera/pmFPAMosaic.c	(revision 38458)
@@ -23,8 +23,10 @@
 #define CELL_LIST_BUFFER 10             // Buffer size for cell lists
 
-#define BLANK_VALUE 0.0                 // Value for pixels that are blank in the mosaicked image (e.g., //
+// #define BLANK_VALUE 0.0                 // Value for pixels that are blank in the mosaicked image (e.g., //
+
+#define BLANK_VALUE NAN                 // Value for pixels that are blank in the mosaicked image (e.g., //
                                         // between cells).
                                         // XXX This should ultimately be set to NAN, but psphot doesn't like
-                                        // that (masking needs to be more thorough).
+                                        // that (masking needs to be more thorough). -- still true??
 
 //////////////////////////////////////////////////////////////////////////////////////////////////////////////