Testing Antlia Quad Band Anti-Light - Strange Halos

you didn't specify which camera you used for the test… in any case, try placing an IRCUT filter on the optical train… before or after the camera and see if it still does it

The ASI 294 does not have an integrated IRCUT filter… I would try with a camera that has this filter to evaluate whether the halos are due to this. Will I be wrong? maybe… but not everyone has the 294, others also have cameras like the 2600 which natively mount an ircut

I tested on Vega the filter, with ASI 294 MC and 150DP F4 Skywatcher, the result is better (the last image was with RC8) but I can see artificat of the microlens of the camera  I will test on the IC434 this weekend, I will give you fedback soon.

Hello Marco, what kind of a telescope do you use?  I am thinking that you have been used a Newton, a RC system . That kind of telescopes procuced always halos around the bright stars and of course large spikes. 
But your image shows too much artifacts. I am thinking that this filter from Atilia is not the right filter for your equipment. Perhaps you have some more filters against light pollution. I am using the Atillia Alp- T 2 Dual Band H Alpha and O III of 5 Nm. It works very good with my Boren Simon Astrograph F 2,8.
Exposuretimes of 720 seconds are possible, of course I can still see some spikes around bright stars and sometimes halos.
These artifacts are very simple to resolve:  Blur X Terminator of RC Astro does the work for you, so that you have a better image. You can try a demo version of 30 days, it is free and shows all the possiblities and you can save the result on your PC. I wish you succes if you want to try that demo version. Perhaps it helps to minisize your artefacts. See my image of the Cygnus Wall, 720 seconds exposure time with a filter from Optolong, the L eNhance 2 made with my Boren Simon at F 2,8, the canera was a SBIG ST 4000 XCM and a self guiding chip. Made on August 14th 2023 in the Netherlands.Untitled488 NGC 7000 Cygnus Wall BS 250 mm F 2,8 ST 4000 XCM Optolong L eXtreme 2 TC 237 G 11 21-08-2023.jpg

Dear,
good news, the problem on IC434 is not visible, there are no artifacts,  with 150DP F4 Skywatcher and ZWO ASI 294 MC, under the single 300" image from Alnitak.

I think we can conclude that the problems I encountered at the beginning were due to the RC8 setup.

Yesterday, I tested on NGC6992, I got 3 hours of exposure. I share the link with you:   https://www.astrobin.com/bgtvrt/ 

Tonight I shot the M33, I will post it on Astrobin soon.

Thank you all for your support.