Index: trunk/ppStack/src/ppStackThread.c
===================================================================
--- trunk/ppStack/src/ppStackThread.c	(revision 20711)
+++ trunk/ppStack/src/ppStackThread.c	(revision 21366)
@@ -38,15 +38,15 @@
         psFitsClose(stack->imageFits->data[i]);
         psFitsClose(stack->maskFits->data[i]);
-        psFitsClose(stack->weightFits->data[i]);
-        stack->imageFits->data[i] = stack->maskFits->data[i] = stack->weightFits->data[i] = NULL;
+        psFitsClose(stack->varianceFits->data[i]);
+        stack->imageFits->data[i] = stack->maskFits->data[i] = stack->varianceFits->data[i] = NULL;
     }
     psFree(stack->imageFits);
     psFree(stack->maskFits);
-    psFree(stack->weightFits);
+    psFree(stack->varianceFits);
     return;
 }
 
 ppStackThreadData *ppStackThreadDataSetup(const psArray *cells, const psArray *imageNames,
-                                          const psArray *maskNames, const psArray *weightNames,
+                                          const psArray *maskNames, const psArray *varianceNames,
                                           const pmConfig *config)
 {
@@ -54,5 +54,5 @@
     PS_ASSERT_ARRAYS_SIZE_EQUAL(cells, imageNames, NULL);
     PS_ASSERT_ARRAYS_SIZE_EQUAL(cells, maskNames, NULL);
-    PS_ASSERT_ARRAYS_SIZE_EQUAL(cells, weightNames, NULL);
+    PS_ASSERT_ARRAYS_SIZE_EQUAL(cells, varianceNames, NULL);
 
     ppStackThreadData *stack = psAlloc(sizeof(ppStackThreadData)); // Thread data, to return
@@ -64,5 +64,5 @@
     stack->imageFits  = psArrayAlloc(numInputs);
     stack->maskFits   = psArrayAlloc(numInputs);
-    stack->weightFits = psArrayAlloc(numInputs);
+    stack->varianceFits = psArrayAlloc(numInputs);
     for (int i = 0; i < numInputs; i++) {
         if (!cells->data[i]) {
@@ -73,14 +73,14 @@
         psString imageResolved = pmConfigConvertFilename(imageNames->data[i], config, false, false);
         psString maskResolved = pmConfigConvertFilename(maskNames->data[i], config, false, false);
-        psString weightResolved = pmConfigConvertFilename(weightNames->data[i], config, false, false);
+        psString varianceResolved = pmConfigConvertFilename(varianceNames->data[i], config, false, false);
         stack->imageFits->data[i] = psFitsOpen(imageResolved, "r");
         stack->maskFits->data[i] = psFitsOpen(maskResolved, "r");
-        stack->weightFits->data[i] = psFitsOpen(weightResolved, "r");
+        stack->varianceFits->data[i] = psFitsOpen(varianceResolved, "r");
         psFree(imageResolved);
         psFree(maskResolved);
-        psFree(weightResolved);
-        if (!stack->imageFits->data[i] || !stack->maskFits->data[i] || !stack->weightFits->data[i]) {
+        psFree(varianceResolved);
+        if (!stack->imageFits->data[i] || !stack->maskFits->data[i] || !stack->varianceFits->data[i]) {
             psError(PS_ERR_UNKNOWN, false, "Unable to open convolved files %s, %s, %s",
-                    (char*)imageNames->data[i], (char*)maskNames->data[i], (char*)weightNames->data[i]);
+                    (char*)imageNames->data[i], (char*)maskNames->data[i], (char*)varianceNames->data[i]);
             return false;
         }
@@ -156,14 +156,14 @@
                 // override the recorded last scan
                 ro->thisImageScan  = thread->firstScan;
-                ro->thisWeightScan = thread->firstScan;
+                ro->thisVarianceScan = thread->firstScan;
                 ro->thisMaskScan   = thread->firstScan;
                 ro->lastImageScan  = thread->lastScan;
                 ro->lastMaskScan   = thread->lastScan;
-                ro->lastWeightScan = thread->lastScan;
+                ro->lastVarianceScan = thread->lastScan;
                 ro->forceScan      = true;
 
                 psFits *imageFits  = stack->imageFits->data[i]; // FITS file for image
                 psFits *maskFits   = stack->maskFits->data[i]; // FITS file for mask
-                psFits *weightFits = stack->weightFits->data[i]; // FITS file for weight
+                psFits *varianceFits = stack->varianceFits->data[i]; // FITS file for variance
 
 
@@ -189,8 +189,9 @@
                 }
 
-                if (pmReadoutMoreWeight(ro, weightFits, 0, rows, config)) {
+                if (pmReadoutMoreVariance(ro, varianceFits, 0, rows, config)) {
                     keepReading = true;
-                    if (!pmReadoutReadChunkWeight(ro, weightFits, 0, rows, overlap, config)) {
-                        psError(PS_ERR_IO, false, "Unable to read chunk %d for file PPSTACK.INPUT.WEIGHT %d",
+                    if (!pmReadoutReadChunkVariance(ro, varianceFits, 0, rows, overlap, config)) {
+                        psError(PS_ERR_IO, false,
+                                "Unable to read chunk %d for file PPSTACK.INPUT.VARIANCE %d",
                                 numChunk, i);
                         *status = false;