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Old 10-01-2020, 01:42 PM
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multiweb (Marc)
ze frogginator

multiweb is offline
Join Date: Oct 2007
Location: Hinchinbrook
Posts: 20,348
Originally Posted by HeavyT View Post
Cheers mate, I'm at 765mm (900 x 0.85 reducer / flattener) using ZWO 36mm filters, 7nm.

Is it normal for Oxygen subs to look blurry even with a focused Bahtinov pattern?
Yeah Oiii let's light in around the blues, turquoise colors. Blues are very likely to be scattered by the atmosphere. Ha is the high end of the deep red and that's always sharp and tight. So it's normal. You can work around it by shooting your Oii closer to the zenith or higher in the sky. Less air to go through.
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