Index: trunk/ppSub/src/ppSubCamera.c
===================================================================
--- trunk/ppSub/src/ppSubCamera.c	(revision 23299)
+++ trunk/ppSub/src/ppSubCamera.c	(revision 23309)
@@ -180,15 +180,33 @@
 
     // Convolved input image
-    defineOutputFile(config, input, "PPSUB.INPUT.CONV", PM_FPA_FILE_IMAGE);
-    defineOutputFile(config, input, "PPSUB.INPUT.CONV.MASK", PM_FPA_FILE_MASK);
+    pmFPAfile *inConvImage = defineOutputFile(config, input, "PPSUB.INPUT.CONV", PM_FPA_FILE_IMAGE);
+    pmFPAfile *inConvMask = defineOutputFile(config, input, "PPSUB.INPUT.CONV.MASK", PM_FPA_FILE_MASK);
+    if (!inConvImage || !inConvMask) {
+        psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+        return false;
+    }
     if (inVar) {
-        defineOutputFile(config, input, "PPSUB.INPUT.CONV.VARIANCE", PM_FPA_FILE_VARIANCE);
+        pmFPAfile *inConvVar = defineOutputFile(config, input, "PPSUB.INPUT.CONV.VARIANCE",
+                                                PM_FPA_FILE_VARIANCE);
+        if (!inConvVar) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+            return false;
+        }
     }
 
     // Convolved ref image
-    defineOutputFile(config, input, "PPSUB.REF.CONV", PM_FPA_FILE_IMAGE);
-    defineOutputFile(config, input, "PPSUB.REF.CONV.MASK", PM_FPA_FILE_MASK);
+    pmFPAfile *refConvImage = defineOutputFile(config, input, "PPSUB.REF.CONV", PM_FPA_FILE_IMAGE);
+    pmFPAfile *refConvMask = defineOutputFile(config, input, "PPSUB.REF.CONV.MASK", PM_FPA_FILE_MASK);
+    if (!refConvImage || !refConvMask) {
+        psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+        return false;
+    }
     if (refVar) {
-        defineOutputFile(config, input, "PPSUB.REF.CONV.VARIANCE", PM_FPA_FILE_VARIANCE);
+        pmFPAfile *refConvVar = defineOutputFile(config, input, "PPSUB.REF.CONV.VARIANCE",
+                                                 PM_FPA_FILE_VARIANCE);
+        if (!refConvVar) {
+            psError(PS_ERR_UNKNOWN, false, "Unable to define output files");
+            return false;
+        }
     }