Red halos with Radi...
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Red halos with Radian Triad Ultra Quad-Band Narrowband Filter  


White Dwarf Customer
Joined: 3 years ago
Posts: 10
July 21, 2021 16:33  

I'm getting red halos around all stars when integrating with APP with Radian quad band filter lights.

With the same config in APP, when I integrate my lights from other filters (Optolong L-Pro is on the right) I don't get the halos (attached left is Radian quad and right is Optolong L-Pro). Also, all subs using the Radian quad filter have pure white stars, no halos:


Is there any easy fix to this? I'm hoping there is some setting I'm using in APP that is causing this - is there an easy way I can share all the APP settings in a forum post?

I'm too novice to know all the differences in the options I'm selecting in the tool though, I select the bayer in tab 0 and I use the bayer dithering, other than that for the most part using default settings (a few others I've changed like rejection, normalization etc but I don't believe those could be creating this?)

The camera is the ASI2600 MC pro (color) and lights are 5min.

Is it as simple as altering the multipliers? Given the real differences in the halos (vast variation) it seems just a broad multiplier will give very mixed results:



Thx for suggestions


This topic was modified 2 months ago 2 times by chasdso

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White Dwarf Customer
Joined: 3 years ago
Posts: 10
July 23, 2021 21:10  

Anyone have insight on why the red halos are happening only with the Radian Triad Ultra Quad-Band Narrowband Filter?

I can work them out somewhat with a lot of patience - but I'd love to understand what is causing this and to eliminate -

They are not visible in subs (Radian ultra subs)

They do not occur with same APP stack settings when I use other filters like Optoplong L-Pro.


Thanks for suggestions!

Main Sequence Star Customer
Joined: 1 year ago
Posts: 25
July 23, 2021 21:49  

Hi, first, leave everything on default in tab 0.
No need to change (AAP will recognise 2600 fits).

Although QUAD band, this looks similar to Dual band, mostly prominent Ha (red) / Oiii (green/blue) colors, especially for stars.

L-Pro is wide band RGB, hence you will see regular star color (red-orange to white, to blue), as opposed to any multi-narrow filter (the quad, l-enhance, l-extreme, etc).

See image here, from a photo i finished with l-extreme (dual band Oiii+Ha)
This is of course after process, reduction, neutralization, wb adjust, etc.



And this is another old shot (with the l-pro) natural colors for stars: