Index: trunk/psModules/src/camera/pmFPAMaskWeight.c
===================================================================
--- trunk/psModules/src/camera/pmFPAMaskWeight.c	(revision 25377)
+++ trunk/psModules/src/camera/pmFPAMaskWeight.c	(revision 25379)
@@ -421,5 +421,6 @@
     psFree(signoise);
 
-    float correction = 1.0 / stats->robustStdev; // Correction factor
+    float covar = sqrtf(psImageCovarianceFactor(readout->covariance)); // Covariance factor
+    float correction = stats->robustStdev / covar; // Correction factor
     psFree(stats);
     psLogMsg("psModules.camera", PS_LOG_DETAIL, "Variance renormalisation factor is %f", correction);
@@ -440,4 +441,5 @@
                        PS_SQR(correction), correction);
         psMetadataAddStr(hdu->header, PS_LIST_TAIL, "HISTORY", PS_META_DUPLICATE_OK, NULL, history);
+        psFree(history);
     }