Index: /trunk/ippconfig/megacam/ppImage.config
===================================================================
--- /trunk/ippconfig/megacam/ppImage.config	(revision 11102)
+++ /trunk/ippconfig/megacam/ppImage.config	(revision 11103)
@@ -7,34 +7,42 @@
 OVERSCAN.STAT		STR	MEAN		# MEAN | MEDIAN
 
-# this table lists constraints which should be applied when selecting the
-# detrend images. 
+# for a test, turn off selected detrend types
+OVERSCAN	BOOL	FALSE		# Overscan subtraction
+BIAS		BOOL	FALSE		# Bias subtraction
+DARK		BOOL	TRUE		# Dark subtraction
+FLAT		BOOL	TRUE		# Flat-field normalisation
+
+# megacam needs fringe subtraction
+FRINGE		BOOL	TRUE		# Fringe subtraction
+
+# this table lists extra constraints which should be applied when
+# selecting the detrend images.
+# note: camera and time are always applied
+
 DETREND.CONSTRAINTS  METADATA
   BIAS METADATA
-    CAMERA  STR FPA.INSTRUMENT
-    TIME    STR FPA.TIME
     DETTEMP STR FPA.TEMP
   END
   DARK METADATA
-    CAMERA  STR FPA.INSTRUMENT
-    TIME    STR FPA.TIME
     DETTEMP STR FPA.TEMP
     EXPTIME STR FPA.EXPTIME
   END
   FLAT METADATA
-    CAMERA  STR FPA.INSTRUMENT
-    TIME    STR FPA.TIME
-    FILTER  STR FPA.FILTER
+    FILTER  STR FILTER.ID:FPA.FILTER
     VERSION STR RAW
   END
-  FRINGE
-    CAMERA  STR FPA.INSTRUMENT
-    TIME    STR FPA.TIME
-    FILTER  STR FPA.FILTER
-    AIRMASS STR FPA.AIRMASS
-    TWITIME STR TWILIGHT.TIME
+  FRINGE METADATA
+    FILTER   STR FPA.FILTER
+    AIRMASS  STR FPA.AIRMASS
+    TWILIGHT STR TWILIGHT:FPA.TIME
   END
-  SHUTTER
-    CAMERA  STR FPA.INSTRUMENT
-    TIME    STR FPA.TIME
+  SHUTTER METADATA
   END	
 END
+
+# only apply the fringe for these filters
+FRINGE.FILTERS  MULTI
+FRINGE.FILTERS	STR r
+FRINGE.FILTERS	STR i
+FRINGE.FILTERS	STR z
+