Index: /trunk/psphot/src/psphotPetrosianRadialBins.c
===================================================================
--- /trunk/psphot/src/psphotPetrosianRadialBins.c	(revision 36114)
+++ /trunk/psphot/src/psphotPetrosianRadialBins.c	(revision 36115)
@@ -36,5 +36,5 @@
     pmSourceRadialProfile *profile = source->extpars->petProfile;
 
-    float skyModelErrorSQ = PS_SQR(skynoise);
+    // float skyModelErrorSQ = PS_SQR(skynoise);
 
     int nMax = radiusMax;
@@ -133,16 +133,17 @@
 	if (radius->data.F32[i] > Rmax) {
 	    // calculate the value for the nOut bin
-	    float value, dvalue;
+	    float value; // , dvalue;
 	    if (values->n > 0) {
 		psVectorStats (stats, values, NULL, NULL, 0);
 		value = stats->robustMedian;
-		dvalue = stats->robustStdev;
+		// dvalue = stats->robustStdev;
 	    } else {
 		value = NAN;
-		dvalue = NAN;
+		// dvalue = NAN;
 	    }
 
 	    binSB->data.F32[nOut] = value;
-	    binSBstdev->data.F32[nOut] = sqrt(PS_SQR(dvalue) / values->n + skyModelErrorSQ);
+	    // binSBstdev->data.F32[nOut] = sqrt(PS_SQR(dvalue) / values->n + skyModelErrorSQ);
+	    binSBstdev->data.F32[nOut] = skynoise / sqrt(values->n);
 	    binFill->data.F32[nOut] = values->n / binArea->data.F32[nOut];