Index: trunk/psphot/src/psphotChipParams.c
===================================================================
--- trunk/psphot/src/psphotChipParams.c	(revision 39926)
+++ 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 39926)
+++ trunk/psphot/src/psphotReadoutMinimal.c	(revision 40034)
@@ -90,4 +90,5 @@
     psphotKronIterate(config, view, filerule, 1);
 
+    // MEH -- sensless for SSdfiffs...
     psphotChipParams (config, view, filerule);