I've duplicated this question on the PEMPro forum of CCDWare, then noted a query between PEMPro vs Tpoint dating back to April 2011. It's of real interest because the author of TPoint - Patrick Wallace - comes into the thread on page 2 and he and Ray Gralak do a real masters course on the issue!
http://ccdware.infopop.cc/eve/forums...8/m/1377011106