Index: trunk/psphot/src/psphotSourceSize.c
===================================================================
--- trunk/psphot/src/psphotSourceSize.c	(revision 27532)
+++ trunk/psphot/src/psphotSourceSize.c	(revision 27657)
@@ -44,6 +44,11 @@
     psAssert (status, "programming error: must define PSPHOT.INPUT.NUM");
 
+    // skip the chisq image (optionally?)
+    int chisqNum = psMetadataLookupS32 (&status, config->arguments, "PSPHOT.CHISQ.NUM");
+    if (!status) chisqNum = -1;
+
     // loop over the available readouts
     for (int i = 0; i < num; i++) {
+	if (i == chisqNum) continue; // skip chisq image
 	if (!psphotSourceSizeReadout (config, view, "PSPHOT.INPUT", i, recipe, getPSFsize)) {
             psError (PSPHOT_ERR_CONFIG, false, "failed on source size analysis for PSPHOT.INPUT entry %d", i);