Quote:
Originally Posted by Peter.M
In my opinion, the image comparison on your site is misleading. While it shows a marked improvement, the first image is guided horribly, stars are not even round in the first place. Secondly, is the only difference between the two setups the NIR guiding? Who is to say, this is not an example of how well SBIGS AO works since that is mentioned in the text.
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Fair comments Peter,
In both cases (with and without the ONAG) the AO-L was used, the difference is only visible versus NIR guidance.
I think the text could be clearer on this matter, thanks for the question I'll complete it eventually.
I agree that the first image shows some elongated stars too, guiding at 14 degrees over the horizon was quite challenging even with the AO-L enabled, this is a bit an extreme situation.
Obviously I would not recommend to do so, the target was chosen so low above the horizon to test the seeing effect on guiding with visible and NIR under bad conditions.
But even if you correct for the star elongations there is still a significant difference using visible or NIR for auto-guiding (same scope, AO, and target).