Index: /trunk/ippconfig/recipes/psphot.config
===================================================================
--- /trunk/ippconfig/recipes/psphot.config	(revision 40033)
+++ /trunk/ippconfig/recipes/psphot.config	(revision 40034)
@@ -90,4 +90,7 @@
 # calculate difference stats?
 DIFF_STATS                          BOOL  FALSE
+
+# add backward chip mapping
+CHIP_PARAMS                         BOOL  TRUE
 
 # basic object statistics
@@ -687,5 +690,5 @@
 DIFF	METADATA
   DIFF_STATS			    BOOL TRUE	       # Calculate diff-specific stats
-  OUTPUT.FORMAT		            STR  PS1_DV3       # Format of output file
+  OUTPUT.FORMAT		            STR  PS1_DV5       # Format of output file
 
   # Extended source fit parameters
@@ -701,4 +704,25 @@
 END
 
+# Recipe overrides for STACK-STACK DIFF
+STACK_DIFF         METADATA
+  DIFF_STATS                        BOOL TRUE          # Calculate diff-specific stats
+  OUTPUT.FORMAT                     STR  PS1_DV5       # Format of output file
+
+  CHIP_PARAMS                       BOOL FALSE
+
+  # Extended source fit parameters
+  # these models are used for high-quality shape analysis after all sources have been removed
+  EXTENDED_SOURCE_FITS                BOOL  TRUE  # perform the detailed extended sourc fits?
+  EXT_MODEL                           STR   PS_MODEL_TRAIL
+
+  # extended source models applied to sources
+  EXTENDED_SOURCE_MODELS METADATA
+    TYPE      EXTENDED_SOURCE_MODEL  MODEL            SNLIM   PSF_CONVOLVED
+    TRAIL_RAW EXTENDED_SOURCE_MODEL  PS_MODEL_TRAIL    10.0   FALSE
+  END
+END
+
+
+
 # Recipe overrides for DIFF_PV3
 DIFF_PV3	METADATA
@@ -721,5 +745,5 @@
   PEAKS_NSIGMA_LIMIT_2              F32  3.5           # peak significance threshold -- MOPS would like to see 4.0->3.5 since ppMops fixed
   DIFF_STATS			    BOOL TRUE	       # Calculate diff-specific stats
-  OUTPUT.FORMAT		            STR  PS1_DV3       # Format of output file
+  OUTPUT.FORMAT		            STR  PS1_DV5       # Format of output file
 
   PSF_FIT_MODEL_SUM_FRAC_CUT        F32  0.5
Index: /trunk/ippconfig/recipes/reductionClasses.mdc
===================================================================
--- /trunk/ippconfig/recipes/reductionClasses.mdc	(revision 40033)
+++ /trunk/ippconfig/recipes/reductionClasses.mdc	(revision 40034)
@@ -665,8 +665,8 @@
 END
 
-# reduction class specifically for warpwarp diffs:
+# reduction class specifically for stackstack diffs:
 STACKSTACK	METADATA
 	DIFF_PPSUB	STR	STACKSTACK
-	DIFF_PSPHOT	STR	DIFF
+	DIFF_PSPHOT	STR	STACK_DIFF
 	JPEG_BIN1	STR	PPIMAGE_J1
 	JPEG_BIN2	STR	PPIMAGE_J2
Index: /trunk/psphot/src/psphotChipParams.c
===================================================================
--- /trunk/psphot/src/psphotChipParams.c	(revision 40033)
+++ /trunk/psphot/src/psphotChipParams.c	(revision 40034)
@@ -34,4 +34,11 @@
     psAssert (recipe, "missing recipe?");
 
+    //MEH -- shouldn't do if input is stack... will need to be a config option for now
+    // -- return true method like for psphotExtendedSourceFits to be consistent...
+    if (!psMetadataLookupBool (&status, recipe, "CHIP_PARAMS")) {
+        psLogMsg ("psphot", PS_LOG_INFO, "stack -- skipping backward chip mapping \n");
+        return true;
+    }
+
     int num = psphotFileruleCount(config, filerule);
 
@@ -59,5 +66,5 @@
         if (!psphotChipParamsReadout (config, recipe, view, filerule, readout, sources)) {
             psError (PSPHOT_ERR_CONFIG, false, "failed to measure magnitudes for %s entry %d", filerule, i);
-            return false;
+             return false;
         }
     }
Index: /trunk/psphot/src/psphotReadoutMinimal.c
===================================================================
--- /trunk/psphot/src/psphotReadoutMinimal.c	(revision 40033)
+++ /trunk/psphot/src/psphotReadoutMinimal.c	(revision 40034)
@@ -90,4 +90,5 @@
     psphotKronIterate(config, view, filerule, 1);
 
+    // MEH -- sensless for SSdfiffs...
     psphotChipParams (config, view, filerule);