Index: trunk/psastro/src/psastroChooseRefstars.c
===================================================================
--- trunk/psastro/src/psastroChooseRefstars.c	(revision 15941)
+++ trunk/psastro/src/psastroChooseRefstars.c	(revision 15963)
@@ -22,6 +22,7 @@
     }
 
-    float fieldExtra = psMetadataLookupS32 (&status, recipe, "PSASTRO.FIELD.EXTRA");
-    if (!status) fieldExtra = 0.0;
+    // extra field fraction to add
+    double fieldPadding = psMetadataLookupF32 (&status, recipe, "PSASTRO.FIELD.PADDING");
+    if (!status) fieldPadding = 0.0;
 
     bool matchLumFunc = psMetadataLookupBool (&status, recipe, "PSASTRO.MATCH.LUMFUNC");
@@ -55,8 +56,8 @@
                 int Ny = psMetadataLookupS32 (&status, hdu->header, "NAXIS2");
 
-                float minX = -fieldExtra*Nx;
-                float maxX = (1+fieldExtra)*Nx;
-                float minY = -fieldExtra*Ny;
-                float maxY = (1+fieldExtra)*Ny;
+                float minX = -fieldPadding*Nx;
+                float maxX = (1+fieldPadding)*Nx;
+                float minY = -fieldPadding*Ny;
+                float maxY = (1+fieldPadding)*Ny;
 
                 // the refstars is a subset within range of this chip
Index: trunk/psastro/src/psastroLoadRefstars.c
===================================================================
--- trunk/psastro/src/psastroLoadRefstars.c	(revision 15941)
+++ trunk/psastro/src/psastroLoadRefstars.c	(revision 15963)
@@ -15,4 +15,16 @@
     float DECmin = DEG_RAD*psMetadataLookupF32(NULL, recipe, "DEC_MIN");
     float DECmax = DEG_RAD*psMetadataLookupF32(NULL, recipe, "DEC_MAX");
+
+    // extra field fraction to add
+    double fieldPadding = psMetadataLookupF32 (&status, recipe, "PSASTRO.FIELD.PADDING");
+    PS_ASSERT (status, NULL);
+
+    float dRA = RAmax - RAmin;
+    RAmin -= dRA * fieldPadding;
+    RAmax += dRA * fieldPadding;
+
+    float dDEC = DECmax - DECmin;
+    DECmin -= dDEC * fieldPadding;
+    DECmax += dDEC * fieldPadding;
 
     // XXX CATDIR needs to look up abstracted name from psastro.config