A few hours without clouds and a lovely moon during twilight at mean distance and favorable libration, mostly transparent air but turbulent ripples the worse the later the evening. Out of curiosity I purchased the latest Takahashi 2x Ortho barlow lens (
https://www.takahashijapan.com/ct-news/topics/23xii15_info_2xOB.html). My first impression is thoroughly positive also considering that the thread diameter of the lens part is 1.25" in that it can be threaded directly to the nose piece of the planetary camera resulting in a lower magnification of 1.6x which is just right for a 2.9µm pixels camera in terms of sampling.
Rev G compares three images stretched to equal height.
For me 1.6x magnification works best though I'd like to repeat the test on a night with calmer seeing.
Rev H: Does anybody know a possible cause of the strong image shift?
Celestron C8
Autoguiding was good
Dither 5x randomly
A mount issue, mirror shift, a dummy at the scope?
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