[gregbradley]

A nice wide field view. Reflections like that are probably best handled by moving the scope a bit. Often they drop out. Chances are this is from the scope not the adapters but yeah check out your adapters. Anodised aluminium reflects IR. Keep in mind Alnitak is about the worst test out there for reflections.

Adjusting the tilt adjuster on your camera should reduce those corner aberrations. Top left are out of focus in the corners and the bottom right shows the most tilt. Bottom left corner looks quite good so that is the standard you need to adjust for all 4 corners.

I think you'll find that from the viewpoint of standing behind the camera the bottom left equates to the top right of you camera.
Top and bottom and left and right are reversed in these compound scopes.

With a methodical approach it can only take 10 minutes to adjust. Not methodical can take a few weeks hehehe.

Greg.