Thread: Elongated Stars
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Old 13-10-2018, 08:50 AM
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barx1963 (Malcolm)
Bright the hawk's flight

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Join Date: Nov 2008
Location: Mt Duneed Vic
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Quote:
Originally Posted by Atmos View Post
A few questions.

- Have you tried them one after another? I’m wondering if it could be something mechanical that changes over time I’d you did LRGB in that order over the course of the night.

- Do you refocus between filter changes or use filter offsets? Sometimes slight refocus can cause non round stars.
Thanks Col
Had 2 consecutive images (end of run with one filter and start of run with next) that were completely different. Focus adjustment was tiny, only a few steps and this focuser uses steps of 0.2667 microns. Of course, it does rack in and out a bit while refocussing (I have it set to refocus on each filter change as have not yet managed to get filter offsets to work, must try again on that one!)
One thing I did find while packing up last night. The focuser (it's a Moonlite Litecrawler) has an adapter to take the 68mm thread in the focuser down to 42 and it has a locking ring on it. That was wound out a little bit so may be causing a bit of sag. Cannot see how that would very between filters though.

Malcolm
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