Index: trunk/tools/eam/teleff/truth.pro
===================================================================
--- trunk/tools/eam/teleff/truth.pro	(revision 41719)
+++ trunk/tools/eam/teleff/truth.pro	(revision 41742)
@@ -158,13 +158,16 @@
 
  sprint pagename page.%03d 0
- book getword regbook $pagename ra      -var Rrad
- book getword regbook $pagename decl    -var Drad
- book getword regbook $pagename dateobs -var dateraw
- book getword regbook $pagename filter  -var FILTER
+ book getword regbook $pagename ra       -var Rrad
+ book getword regbook $pagename decl     -var Drad
+ book getword regbook $pagename dateobs  -var dateraw
+ book getword regbook $pagename exp_time -var exptime
+ book getword regbook $pagename filter   -var FILTER
 
  $TIMEREF = 2000/01/01,00:00:00
  $TIMEFORMAT = mjd
 
+ # shift to the midpoint of the exposure
  ctimes -abs $dateraw -var MJD
+ $MJD += 0.5*$exptime/86400.0
 
  $Ro = $Rrad * 180 / $M_PI