Antlia Filters VS Alnitak and a Hidden Galaxy

After 4 years, I'm going back to the Horsehead Nebula (and Alnitak) to see if these 3nm SHO filters can deal with Alnitak's halo. Also, thanks to a gentle reminder from the Euclid Space telescope team, I'm trying to image the Hidden Galaxy, IC 342, from my Bortle 8 skies.

[@HeavenlyBackyardAstronomy]

Hi James, I have purchased the 4.5nm Antlia narrowband filters and just love them. I decided to go with the 4.5 versus the 3.0 due to ... I didn't want to cancel out too many of the stars. I am extremely pleased the the 4.5nm. I too had issues with Alnitak with ATIK filters and the ZWO 1600. Super large O3 halo plus distortion of Alnitak from the 1600 sensor. I acquired the Player One Poseidon mono camera (IMX 571) and shot the horsehead with it and the Antlia filters ... wow what a difference. Very little halo and a much smoother cleaner view of Alnitak. Good video James.

[@Aero19612]

Hey Pat. I think everyone who uses the Antlia filters is impressed with them. Glad to hear you’re in that camp as well. I watched your vid in the Poseidon - very interesting (been meaning to post a reply and question. Darn it, I watch YT videos on the television and can’t comment unless I remember to go back to the laptop, haha). The market has moved since the time of ZWO and QHY as the only suppliers. Thanks for watching!

[@Aerostar509]

I'm happy with my Antilia 2.8nm filters. Good value for the money. Thanks for the video.

[@Aero19612]

Excellent. I wonder if there’s noticeable difference between the 2.8nm vs the 3.0nm filters? They didn’t have the 2.8 when I bought my 3.0 set (at least I don’t think they did). Thanks for watching!

[@gregerianne3880]

I bit the bullet on the cost of the Antlia filters when I transitioned to a monochrome camera, and I'm very happy I did. The filters are terrific, in my opinion, and although not cheap are not the most expensive option out there. Very happy with them, and glad you got a good result with them, James! Edit: Have you seen this video by VisibleDark: kzbin.info/www/bejne/nqbZnGOAhdKSrJY Shawn gives a nice algorithm for preventing the loss of stars when removing them to process the galaxy separately.

[@Aero19612]

Totally agree with you, Greg. No, I haven’t seen the video. I will often use a mask to remove just the stars outside of the galaxy disk, deal with them separately, and then blend back in. Thanks for watching!

[@captaindanield5827]

The horse head / Flame was my first target. I go back to it every fall and winter as a touchstone to see how my equipment is doing and test new techniques. The one thing I always use to judge my image is the little companion star next to Alnitak. If it stands out distinctly, then I consider that a better indication of a good image. If Alnitak "eats" it up, then I think the image could be better. I can just start seeing the little star in your Antlia filter image. Not in the zwo filter image. - While i am sticking with osc for now, I am considering retrieving some HSO data by using a couple of duo band filters (Ha/Olll and Sll/Olll) to collect these narrow bands. Maybe the Altair filter set, either the 4nm or 6nm, still trying to find out if these filters create halos. Asi2600 mc and 152ed doublet F-8 (uder construction a 140mm triplet F6.5 - purchased lens cell, building the rest).

[@Aero19612]

Yep. The Horse head kicked my butt the first time. Nice observation about the small star next to Alnitak! Been so distracted by the stupid halos. Still room for much improvement for me on this target, including adding significant RGB.

[@crateer]

Thanks James, another great video! I just got the 2.5nm 2" Antlia filters (SHO) and just tested them last night for Halos and performance compared to the L-Ultimate. Tested with the horsehead nebula, I can happily report that I got basically no visible/barely visible halos from neither the Ha, Sii or Oiii filter (5min and 10min subs). Blew my mind away. Compared to the halos of the L-Ultimate, which I had used for my DSLR prior getting a mono camera, the Antlias are pretty amazing and way beyond my expectations (my L-Ultimate has significant/bad halos, seems like I lost the lottery there compared to other reviews I found online). I even tested for halos on Capella (Mag 0.24! compared to Alnitaks Mag 1.68) simply because why not test them on an extreme star and because the horsehead was still behind trees at that time, and even there, I got no/no noticable halos for all SHO filters. Prior purchasing I searched for reviews about the 2.5nm filters but could only find a single guy who wrote about them a little bit over at Cloudy Nights, so I wasn't sure whether I could get lucky or not with those filters. The benefit of the 2.5nm compared to the 3nm Antlias (other than a little smaller bandwidth) is the higher emission, which was my reasoning for going with them. Next clear night (hopefully without 70% moon close to Orion) I will do some more testing with long exposures (10minute subs) and most likely post my results online for others as resource. If I do, I will report back here on this comment if anyone is interested?! But until the next clear night without moon close around, it might take a while unfortunately, as the weather here in Germany is insanely bad at the moment.. :/

[@Aero19612]

Excellent feedback! Sounds like you’re getting great results with the Antlia filters too. Capella is a tough test. Your a brave soul. Yes indeed, please let me know how your imaging goes. Thanks for watching!

[@markcollins5901]

Nice video. Thanks, James. -- For what it's worth, I have the Baader CMOS Optimized 3.5 - 4 nm Ultra-Narrowband filter set on one setup, and the Optolong 3 nm set on the other setup. Both of these sets do quite well in Hα and SII, but have noticeable -- but not too terribly bad -- halos in Oiii. By the looks of it, the Oiii halos are roughly on par with your new Antlia Oiii filter. Maybe one day I'll spring for a Chroma filter set. We can always dream, anyway.

[@Aero19612]

Yep. The Antlia filters aren’t magic, but they are good. Haha. The expense of filters is what keeps me from going APS-C or full frame. Thanks for the observations on the Baader and Optolong filters.

[@actudoran]

nice video buddy! been thinking about going mono ... yup filters are a pain ... OTOH there are some dual narrow band filter for Ha and O and O and S that could work ... the final point really is that i would need to bin the camera to achieve the deiserd arcsec resolution for both mt frac and the c11 ... which ultimately spells a mono like 294mm unless i want to go to 432 for c11 and colour for the frac ..

[@Aero19612]

The dual band filters for OSC cameras do a great job (I have the Antlia Ha-OIII and the SII-Hb. They’re great). Mono is a good move, but it is expensive with all of the filters you’ll need. Think “long term” though. I stepped into mono with 1.25” filters and now I feel “trapped” with the smaller sensors. Oh well. Thanks for watching, Alex!

[@zaphus]

Is it wrong that even though this topic interests me (I have Antlia filters) - it's actually the software you created to help decide which targets to image and how much imaging time you get that has me intrigued? Any chance you could do a video on that at some point ? I'd love to have something like that, I've used Telescopius but it doesn't go into details like how long a target is above a particular angle, etc

[@Aero19612]

Haha. Way ahead of you. You might check these videos out: From 4 years ago. If you like technical detail, then start here: kzbin.info/www/bejne/jIHCfKSohJxllassi=uDLQtL_wlT2hAUlV If you want to skip the "math" then skip through this: kzbin.info/www/bejne/haCXpqhnbcmmes0si=E3MJXLrBzJjA1eHY And a more recent re-do: kzbin.info/www/bejne/oX6be6xngNybqJosi=Zdruuj9FZUmfjsyO

[@briangriffiths937]

I captured IC 342 a few years ago, and I will go back to the data regularly when a new tool comes out in Pixinsight. Today I give it another whirl, using the new Graxpert updated script in Pixinsight. With a smoothing factor of zero, using the AI method of Interpolation, I saw a good improvement of the detail in the galaxy.

[@Aero19612]

Interesting. Will have to give that a go. Thanks for the heads up and thanks for watching!

[@billblanshan3021]

If you shoot the horse head again try it without a filter and you're going to see halos. The sensor glass that ZWO uses is actually poor quality and causes not only halos but multi reflections but it's actually not a micro lens effect. I tested this on a few of my ZWO cameras and confirmed this. I was talking about these issues a few years back with the owner of Astronomiks and he is looking at selling a replacement glass for the ZWO cameras to help get rid of this halo and multi reflection issues. Might be worth investigating some more, hint hint 😂

[@Aero19612]

Hey Bill. Sorry for he delayed response. Great feedback! Very interesting observation about the ZWO sensor glass. Kind of reminds me of the fan vibration issue: an otherwise good product being knocked down a peg because of a cheap and easily replaceable element. Hmm. That’s the problem (or is it a good thing), there always “things” to investigate. Haha. Oh well, keeps me out of trouble, I guess.

[@darkrangersinc]

The Antlia 3nm SHO filters have been great and for not much more than the Optolong/ZWO a no brainer

[@Aero19612]

This hobby needs more “no brainers.” Haha. Totally sold on Antlia. That’s why I didn’t hesitate to buy their Ha-Oiii and Hb-Sii filters for my OSC camera. I’m very pleased with those as well. Thanks for watching!

[@mr.b3054]

Good info, noticed very strong halos on Alnitak with the Seestar. I wonder if an external filter would help?

[@Aero19612]

Hmm. I don’t know anything about the Seestar. Have you contacted them? Alnitak is a tough nut though.

[@KPMVAB]

The software you created. Planning to share it 😊?

[@Aero19612]

Haha. Way ahead of you. See this vid and links: kzbin.info/www/bejne/oX6be6xngNybqJosi=SO1gUTqmzz16P8Yo

[@kmh032008]

Agree. I upgraded my SCT and Refractor setup to all Antlia filters. Much better than ZWO and doesn’t break the bank.

[@Aero19612]

Plenty of other ways to break the bank in this hobby. Thanks for watching!

[@UruPTer]

Hi James, I use the Antlia filters for years now and never ever got any halos forming. Are the halos present in the raw images before calibration or are they present in the flats( just a silly thought from me) you probably already checked that. Two days ago I took almost exactly the same image, no halos (also Bortle 8-9 sky). Keep the video's coming. Love them!

[@Aero19612]

Yeah, I do get much smaller halos on other bight, but much less bright than Alnitak, stars. That said, it could be that I need to dial back my exposure time. And there is evidence of reflections with super bright stars. Thanks for the observations and comments!

[@anata5127]

What are best filters for IC434? I have tried 8 filter types (LRGB and ha, Hb, s2 and o3). In my opinion, LRGB-Ha is the best combination for this object. Pure narrow band doesn’t cut, since there are several blue reflection nebulas up there. I am in bortle 8. Could it be photographed? In my option, no optimal picture could be achieved from Bortle 8. I took RGB 2h each in Bortle 3, 8h L and 3h Ha in Bortle 8; then it worked much better. Generally, I run test shot of 3-5 frames for each filter, and know what to do (scope type; filter type, frame time and integration time). After test shots, I don’t attempt many targets from Bortle 8.

[@Aero19612]

I’m inclined to agree with you. My Oiii signal is weak (except for the halos). Probably best to skip this data. Maybe go with Ha, R, G, B and maybe Sii. I don’t think I’d use L for this target. If optimal images are the objective, then Bortle 8 is a very steep climb. That’s not really my objective. I just want to do the best I can from my backyard. I’m not chasing any science objectives or APODs - just an interesting challenge with some problems to solve and a decent image at the end of it.

[@Othman1992on]

Sorry if I didn't catch this, but what is your total integration time of IC 342? Because I live in bortle 9 and this is very motivating. Thanks

[@Aero19612]

I may not have mentioned it. I think it was about 30 hours over L, R, G, B, and Ha. Tough target for bright skies.

[@nerdybeardo]

Have you checked to see if the glass plate on your camera needs cleaning? I had a similar microlensing problem but after I took apart my camera and cleaned it out that went away

[@Aero19612]

That’s a very good suggestion! Thanks!

[@bullshitvendor]

have you ever considered putting a small observatory in your backyard?

[@Aero19612]

Indeed I have. Would love to keep everything outside and cut down on tear down and build up cycles. There are several issues I have here, starting;g with the HOA that doesn’t allow structures taller than the fence. There may be some low profile options. Also, I live in “fear” of my neighs planting a tree right in front of the observatory. So, I decided to ride this out for now. Thanks for watching!

[@bullshitvendor]

@@Aero19612 have you investigated ways of keeping stuff outside more or less permanently without a proper observatory. I m pretty much in the same situation and I m trying to figure out if it s possible to keep the mount and rings permantenly outside on a pier under a telegizmo or somesuch. it s a daunting proposition with a mount that cost $19k but I m way down on imaging time due to the setup/teardown misery. meh

[@Aero19612]

@@bullshitvendor Yes. I experimented with the Telegizmos cover. See video here from 6 years ago: kzbin.info/www/bejne/mmrOoKBmpq6smJYsi=YRVamVuoFbs30cA1 A lot of people leave their scopes and cameras outside under this cover and have no complaints. I guess I'm a bit more squeamish and didn't like the elevated temperatures under this cover for the hot months here in Texas (do I really want my scope and electronics exposed to 130 F?). I'm also concerned about humidity and bugs/spiders etc. So, in the end, I leave my mount out under a cover when we have a string of good imaging nights, but I always bring the scope/camera in every morning. When we have a string of bad weather, I bring the mount inside. Far from the perfect scenario I would like to have.

[@Ronbo765]

No posts in 2 mos. Where the heck have you been?

[@Aero19612]

Hey Ron. I ask myself that same question all of the time, haha. Yeah, been slammed with work so not much free time to make videos. I've got a few in mind.

[@Ronbo765]

@@Aero19612 Great! Hopefully you'll post soon.

[@johnsmith-rd9rr]

Sent ya a email

[@Aero19612]

If you did send an email, I didn’t get it…