Index: trunk/psphot/src/psphotApResid.c
===================================================================
--- trunk/psphot/src/psphotApResid.c	(revision 9526)
+++ trunk/psphot/src/psphotApResid.c	(revision 9529)
@@ -73,5 +73,5 @@
 	}
 
-	dMag->data.F64[Npsf] = model->dparams->data.F32[PM_PAR_FLUX] / model->params->data.F32[PM_PAR_FLUX];
+	dMag->data.F64[Npsf] = model->dparams->data.F32[PM_PAR_I0] / model->params->data.F32[PM_PAR_I0];
 
 	psVectorExtend (mask, 	 100, 1);