Thanks for the feedback jd.
Thanks for pointing out the collimation difference between the barlow and no barlow sessions. I had not even processed that since I knew that nothing changed with the collimation. The collimation has held up for months now without a change. I was even surprised by the small amount in the barlow photo because it looks spot on with the Tri-B and Duncan masks.
I did catch that you were insulated. I stored in an unheated pole barn and found that if the delta was greater than around 6° or if the temperature drop significantly during viewing, the insulation ultimately fails. That is, initial star tests were great, but later ones showed thermals. I added fans and my views of the planets and airy disks became much more consistent, though still very dependent upon good seeing.
Pickering scale. You should be able to evaluate an airy disk, though it is unlikely to be as clean as with the 5" refractor shown in the animations, due to the larger aperture of the C11. One difference is in the flaring. I've had two nights where the refractor on top showed 10/10, but the C11's first ring had some slight flaring (8/10), though it was very well formed and very still. Still is good! Especially with the central disc. Another difference is that when seeing is bad 1 to 3/10, your central disk will become quite large and broken/broiling within. In good seeing and proper acclimation, it is smaller than what is shown in the animations, again, due to the aperture.
The point is not really about about the Pickering Scale, it's that thermals within an OTA are going to appear much the same as bad seeing. It's hard to tell them apart unless you happen to have a refractor to compare with. Not saying you should use one, rather be aware and look for consistency in an occasional in focus or out of focus star test.
Also, if you have a nice well formed first diffraction ring that is concentric to the central disk, you know your collimated. Flaring to one side, not so much. These in focus star test are much easier to see in mag 3-4 stars than mag 1 stars and at ridiculously high mags due to how small the central disc gets with more aperture. I generally use 667x in my C11, but 500x might get it done.
Edited by Migwan, 12 August 2021 - 06:03 AM.