Star Halo Test Antlia Golden Dual band Filter

[Startrek]

I wanted to prove all the media hype about the Antlia Golden OSC Filter having little or no halo around Stars compared to my L Exteme which does.
Tuesday night was clear in Sydney so picked the bright nebula M8 Lagoon which has quite a few medium to larger sized stars as a test

6” f6 Bintel GSO Newt
EQ6-R pro mount
ZWO2600MC cooled to -10C Gain 100
Antlia Golden Dual band OSC filter ( Ha 5mn / Oiii 5mn )
TS Optics GPU coma corrector
45 x 2 minute dithered guided subs
40 x Flats
60 x Bias
PHD2 Multistar guiding ( atmospheric conditions were average, guiding started out at 0.60 and ended up 0.80 )
EQMOD, Stellarium, APT
Stacked in DSS
Processed in Startools V1.7 Compose OSC NB Bi Colour

Processed some different versions to check for any Halo around the stars
Synthetic Luminance
SHO bi colour versions
Interpolate bi colour versions

The results from the Antlia filter were pretty damn good ( almost no Halo ) compared to my L Extreme which had a pronounced Halo
Obviously I’m imaging with a Newt so results might be different say for a refractor ???
Antlia do make the same dual band filter for faster optics f2.2 to f3.6

Comments most welcome
Thanks

[RyanJones]

Good to see you testing out the new equipment Martin.

May I suggest a more effective test would be of a bright star in a star field. Maybe Achernar would be a good choice at the moment. Take an image with the main bright star on and off axis. Split the resulting channels and show the halo or lack their of for each channel. Unprocessed raw from the camera . You could also take one with no filter as a control image and if you still have the L-Extreme, repeat the process so you are comparing apples with apples from the same night and same equipment. Also testing with the f6 is likely to result in significantly reduced halos than your f/5s. I’m not sure if you have the 8 with you in Sydney or if it’s down south with your 10”. If you don’t you’ll have to wait for the real test.

Cheers

Ryan

[Dave882]

Looking good Martin- that’s super sharp and the contrast is amazing. I’ve got my eye on this new crop of dual band filters- between this in and the l-ultimate I reckon it’s going to be a game changer for us osc city dwellers!

[Startrek]

Thanks Ryan
Yeh a bright comparison would be ideal
I did compare an M8 captured in June with same scope, similar exposures and the L Extreme and yep halos are exhibited on all medium to larger stars
I also checked a few M8’s with my 8” f5 and L Extreme and yes halos are there similar to the 6” f6
I’m also stoked at the level of detail I pulled out for only 1.5hrs under Bortle 7/8 with only 2 min subs. I get better SNR with 2 min subs using the Antlia ( Ha 5nm , Oiii 5nm ) than I do with 3min subs using the L Extreme ( Ha 7mn , Oiii 7nm ). I agree with Mono and Narrowband filters you can push long subs ( 5min + ) to capture and expose more detail but with OSC ( ZWO2600MC ) at least in my experiences under heavy LP , the longer subs just introduce more noise.
So for the immediate future under Bortle 7/8 in Sydney I’m going to limit my subs to 2min for Narrowband and 60 sec to 90 sec for Broadband
Down South under Bortle 3, I push much longer subs for both NB or BB

Cheers
Martin

[Startrek]

Thanks Dave,
Very happy with the new filter , so much clean detail for very little data under heavy LP
Thumbs up for the Antlia Golden Dusl band filter !!

Cheers
Martin

[Sunfish]

Thanks Martin . Great test and very helpful. Top images

[Startrek]

Thanks Ray

Only used the Antlia filter a few times but it’s a winner , worth the investment
I’m interested to hear any feedback from folk who have bought the Optolong L Ultimate 3nm filter. I’m sure Optolong have rectified the halo issues that I experienced with my L Extreme

Cheers
Martin

[Craig_]

Some nice results Martin. I stuck my head out on Tuesday night (Sydney) considering setting up, but the seeing was absolutely diabolical where I was so didn't bother.

[Nikolas]

I've got an optolong ultimate on order and have finally purchased the Askar FRA300 pro so will be doing a full test when they all arrive
will be selling a few items soon to pay for these :)