Index: /trunk/psphot/src/psphotApResid.c
===================================================================
--- /trunk/psphot/src/psphotApResid.c	(revision 10309)
+++ /trunk/psphot/src/psphotApResid.c	(revision 10310)
@@ -6,6 +6,6 @@
 
 // measure the aperture residual statistics
-bool psphotApResid (pmReadout *readout, psArray *sources, psMetadata *recipe, pmPSF *psf) {
-
+bool psphotApResid (pmReadout *readout, psArray *sources, psMetadata *recipe, pmPSF *psf)
+{
     int Nfail = 0;
     int Nskip = 0;
@@ -30,4 +30,9 @@
     bool IGNORE_GROWTH = psMetadataLookupBool (&status, recipe, "IGNORE_GROWTH");
     bool INTERPOLATE_AP = psMetadataLookupBool (&status, recipe, "INTERPOLATE_AP");
+    int NSTAR_APERTURE_CORRECTION_MIN =
+	psMetadataLookupS32(&status, recipe, "NSTAR_APERTURE_CORRECTION_MIN");
+    if (!status) {
+	NSTAR_APERTURE_CORRECTION_MIN = 5;
+    }
 
     pmSourcePhotometryMode photMode = 0;
@@ -116,6 +121,7 @@
 
     // XXX choose a better value here?
-    if (Npsf < 5) {
-        psError(PSPHOT_ERR_APERTURE, true, "no valid aperture residual sources, giving up");
+    if (Npsf < NSTAR_APERTURE_CORRECTION_MIN) {
+        psError(PSPHOT_ERR_APERTURE, true, "Only %d valid aperture residual sources (need %d), giving up",
+		Npsf, NSTAR_APERTURE_CORRECTION_MIN);
         return false;
     }