Newtonian reflector collimation question After an initial collimation, I took my scope (150mm/750mm) out for a star test. While I could see concentric circles when the bright star is at the centre of the video, when the star is on the side of the view, I get an image typical of an uncollimated scope. Please refer the images below. The left image is how it appears when the bright star is at the centre. The right image is how it appears when the star is on the upper portion of the view.



Does my scope require further collimation, or is it fine the way it is now?
Your scope is f/5. There will always be some coma aberration.
Always, the image quality is worse as you get closer to the edge of the field of view (FOV).
Personally, given that the fact that you will want to observe your targets at the center of the FOV, this collimation would be acceptable.

Happy photon hunting!