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Old 17-12-2020, 12:03 AM
MarkInSpace (Mark)
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Optolong L-extreme - Extreme Halos?

I've got a brand new L-Extreme, and I'm worried.
My first proper image is positively riddled with Halos around the stars, even the moderately bright ones - I've never had this problem with the L-Enhance (which I sold to afford the L-extreme).
the photo was
180sX27 subs
SkyRover 115 F/7 +0.8 flattener reducer
ASI294MC Pro
Halos are present on the individual subs - ouch!
Does this filter always have these halos? Will faster subs reduce the problem?
Help please!!
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  #2  
Old 17-12-2020, 11:04 AM
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Nikolas (Nik)
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I have those halos around the same two stars on the left side but never got halos on my other images, I'm going to try placing the filter drawer as close to the sensor as possible and see if that changes things
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Old 17-12-2020, 11:36 AM
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That looks like internal reflection from filter. Multicoating is missing?

Placing it closer to sensor will help.
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Old 17-12-2020, 04:39 PM
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xa-coupe (Jeff)
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I get it on Alnitak in particular. I've been told more subs and attention in processing will fix it. Still compiling enough subs to make it worth processing thanks to rubbish weather.
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Old 17-12-2020, 09:31 PM
MarkInSpace (Mark)
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The filter is as close as possible with the setup that i have.
Iíll try shorter subs and report back.
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Old 18-12-2020, 06:03 AM
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bojan
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Or.. maybe try to move it away then.
This will produce larger, but fainter circles. At some point (and exposure) they will be fainter than noise and virtually disappear.
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Old 18-12-2020, 11:05 AM
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ChrisV (Chris)
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I've got this filter. I get a bit of halo on brighter stars, but mostly on the green passband. But not like you are getting. Imaging train on my newt is
L-extreme
Baader coma corrector
Spacers - 55mm from corrector to sensor
ASI071

Chris
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Old 19-12-2020, 12:03 PM
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Robert_T
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Quote:
Originally Posted by MarkInSpace View Post
I've got a brand new L-Extreme, and I'm worried.
My first proper image is positively riddled with Halos around the stars, even the moderately bright ones - I've never had this problem with the L-Enhance (which I sold to afford the L-extreme).
the photo was
180sX27 subs
SkyRover 115 F/7 +0.8 flattener reducer
ASI294MC Pro
Halos are present on the individual subs - ouch!
Does this filter always have these halos? Will faster subs reduce the problem?
Help please!!
I get halos with this filter but did with the enhance as well. I have found moving the filter around and trying different drawers etc you can minimise, but it vary from camera to camera as well. Frankly at this stage of my journey I am more concerned with fundamentals like focus and don't mind halos so much. Here's an orion I took with the L-extreme and ASI071mc a few weeks ago... plenty of Haloes as well on brighter stars.
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  #9  
Old 27-12-2020, 09:08 AM
Craig_
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My L-Extreme does halo on very bright stars, but then, so did my Enhance. It does seem worse/more noticeable on this though, which makes sense given the Oiii band is much tighter (7nm vs 24nm). Proper Oiii narrowband filters will also produce halos for the most part, except for Astrodon and Chroma.

I'll be choosing my targets carefully with this filter to avoid it. So far I've used it on Tarantula Nebula and Carina Nebula with good results and no halos, but they lack the super bright stars you see around M42.

I was going to sell my Enhance but might keep it for a while just in case.
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