As I understand it, the Smax number is the theoretical max Strehl possible compared to an unobstructed aperture, most likely calculated from the mask generated from the two fits images. Refractor runs in WinRoddier show Smax at 1.00 so it's understandable that an obstructed optic would have a lower Strehl by definition - and the advertised Strehl would be the comparison ratio of the calculated Strehl to Smax. So for my runs, the Smax of 0.8 is the theoretical max, and the actual returned number of 0.25 and 0.36 as returned from the runs with defocused disks in the ~30 waves defocus range are definitely more indicative of my optics. The 3rd run above does have defocus disks that are too small to get useful/trustable numbers from - about 8 waves of defocus I think, but it does have a nice set of images to show the difference in breakout. I ran the third set through Winroddier just for curiosity purposes to see if the aberrations continued to show in that run. I don't think I could read too much into the numbers or analysis as the deficus disks are too small as per Winroddier forum postings.
I think the severe undercorrection on my mirror is most of the problem, as I really do not ever have a point of best focus, I have more of about a mm where the zone of least confusion is mushy and not dropping near to a point.
Yep, the seeing was not good that evening, but things are typical of this in Ireland with a fairly consistent jet stream overhead for most of the year. These are other videos from that attempt to record a startest. My priority was to try to get the difference in shadow sizes, as that alone is enough to show a Skywatcher rep that the mirror is flawed optically. All of the other optical defects present, the zonal artifact and the 12-spoke pattern seen, definitely contribute to the problem, but not as bad as the undercorrection. That's based on unticking the "higher orders" polynomial selection in the floating window, and seeing the effect the run had on the numbers.
https://youtu.be/vHj10gfUvKY - A slow run through from outside focus to inside, might be a little more clear
https://youtu.be/5HjQGQzKA8Q - I could see cloud coming in for this one, so I just continued racking through focus a number of times.
All of the star test videos start from outside of focus and head inwards, so the large-shadowed video portions are all intra-focal.
One item of interest in the as-captured avi files, I can see a clear Poisson spot in the centre of the disk, with quick rays from the bright portion of the disk as seeing wobbles the lightpath around.
But yes, I'm hopeful that with the star test videos, and the other files I've provided, that the vendor will work on my behalf to get a replacement mirror from the distributor. As it stands I am of the opinion that I have two issues with the mirror that individually would warrant a replacement. One being the optical issues showing up in my recent posts, and the second being the mechanical issues causing the collimation problems. There's no way that a commercial scope from a well-known manufacturer should have had a mirror of that quality pass QA before shipping, and there's no way that a Newt should have that much movement of the central collimation zone when moved in altitude.
I'm not looking for perfection, just good enough to work as-described, which shouldn't be too much to ask.
If the distributor does provide a replacement, I would like to get the mirror tested in the UK before having it shipped to me in Ireland. Any suggestions for this? Would anyone advise against Orion Optics to test?