Hi Matt and Raymo,
After rotating the objective lens a few times, I am pretty certain the scope suffers a little astigmatism, not really bad, but it is there. It is not as bad as before, but obvious especially as star light hits the outer perimeter of the lens.
By opening to full 70mm, the star image is also is softer than when it was stopped down to 60mm. But overall still a fine and versatile scope, I am happy to leave it open to 70mm as opposed to moving the baffle back up to baffling it down to 60mm.
That's why this scope was deliberately stopped down from 70mm to 60mm, as:
http://toothwalker.org/optics/astigmatism.html
Extract of above:
"A trusty method to mitigate image impairment by astigmatism and field curvature is to stop down the lens."
Live and learn something new every day.
Kind regards,
Bill