Your laser collimator, is it collimated this is a fundamental error every newbie makes... its a laser it must be straight. wrong
if the laser isn't centered within the holder game over.
If you are deadly serious about astrophotography cut the !$#@!rap and go buy yourself Cats eye collimation kit - Autocollimator + Collimated Cheshire. Job done instant greatness no stuffing around!
I would say that 99% of your issues are collimation and tracking. not pinched optics or focuser alignment to the tube or any other myriad of things. Get the collimation perfect then you can eliminate that as a cause for anything!
The next step is your Focuser you could have focuser slop causing A. Tilt where the image is focusing at differently at different parts of the sensor. B Flexure... of the two of these flexure is the most frustrating and hardest to eliminate it takes patience time and understanding to figure it out!
Keep up your questions and be sure to give every single bit of detail other wise its like walking into Repco and asking for a part to fix your car without knowing what part/car or year model.
Brendan
