Index: trunk/psModules/src/concepts/pmConceptsStandard.c
===================================================================
--- trunk/psModules/src/concepts/pmConceptsStandard.c	(revision 20597)
+++ trunk/psModules/src/concepts/pmConceptsStandard.c	(revision 20598)
@@ -113,5 +113,6 @@
                         float gain = psMetadataLookupF32(NULL, cell->concepts, "CELL.GAIN"); // Gain (e/ADU)
                         if (!isfinite(gain)) {
-                            psWarning("CELL.READNOISE is supposed to be in ADU, but CELL.GAIN isn't set");
+                            psWarning("CELL.READNOISE is supposed to be in ADU, but CELL.GAIN isn't set -- forcing to 1.0");
+			    gain = 1.0;
                         }
                         rn /= gain;