[Lee]

I've noticed some elongation this week, when previously it wasn't there, and it only seems present in various parts of the sky.
I recently converted from a SBS/guide scope to OAG/lodestar - so the only difference is the OAG in the image train, and everything is threaded together. The OAG itself is in two parts, held by three compression screws though....
The image train is - moonlite focuser/MPCC/TSOAG9/Orion filter wheel/Atik 420.

My thoughts are there is some flex in the OAG at this joint, so I'm planning on pulling it all down and tightening up/collimating etc.

CCDInspector reported collimation is pretty good around 5" off or so, of course my trial expired before I could do some better measurements! Have just registered it, so tonight I may get some more data (expensive software!)....

Does anyone have any advice on this?
Tips to actually diagnose the issue??

The images are high in the NW, and high in the SE this week....

Thanks in advance...