WitchHead Nebula (NgC1909) + Antlia Triband RGB Ultra filter?

High light pollution = No Witch, no matter the filter.

B5 hardly counts as high light pollution. So it actually depends on what the OP situation is.

When I started AP three years ago, with an unmodified Canon EOS 5D4 and the Samyang F=135mm f/2.0, I captured the WitchHead Nebula (NGC1909) by coincidence, not even knowing it was there.

When you read the details, it was only 1h20' total integration time ... but the WitchHead is clearly visible.

Two nights ago I gave it a second try with the same lens and my ZWO ASI533MC Pro ... and The Antlia Triband RB Ultra. Fog rushing into our valley like the tides at the ocean stopped the fun after 1h20' - coincidently the same as three years ago. But this time I can barely see any hint of the WitchHead at all.

Thus I asked ... it may be the very damp air, the incoming fog or whatever.

Glad to read from @Markus he had good luck with the same filter and a similar setup.

Hi, if I understand IC2118 correctly, it is a diffuse reflection nebula, whereas the Antlia Triband RGB Ultra filter as I understand it (being 'narrow-band') is recommended for emission nebulae...

Then from being discouraged to not being able to do it is another matter....
It would also be to understand how light polluted the area is and how high the subject actually is. BUT from what I understand there are so many variables to consider.

I'd try it on principle anyway (I'm someone who likes to bang my head against a wall even if it's advised against!) and at worst throw away a night's worth of data and a day's worth of processing.

I'm a newbie so I could probably be wrong!

Greetings, CS!

F.T.

Thanks for your reply @FilippoTib,

unfortunately good deep sky nights here in our valley in the Alps are rare. The Alps being the European weather divide, are a great barrier between south Europe and central/north Europe where the big weather systems collide and mix, yielding strong and gusty winds, wind shears and severe  turbulences. Also humidity is often 80-90% ... these days 90% thus often yielding fog and/or low cloud covers as can be seen in this animation.

Despite having acceptable light pollution in our valley (Bortle 4), we thus suffer severe limitations indroduced by our local micro climate.

Having said this, good nights are rare and precious. It can take weeks waiting for another good night. Thus it hurts to leave such a night unused or "abused" for experiments.

~ * ~

Concerning the Antlia Triband RGB Ultra I cite from the maker's website:

• "different from other ultra-narrowband filters, it is able to capture galaxies, reflection nebulae"
• "It is workable to shoot galaxies, reflection nebulae and star clusters."

So I expected (read: "hoped") it would work as advertised with NGC1909 / IC2118 and it does work.

I choose  this filter because our atmospheric conditions are unreliable and change fast. It would be a pain to collect Ha for some hours in one night and OIII in the next good night after weeks. I could simply not collect enough photons yet because of this:

Every single day and night tidal clouds rush in and out and in again ...

I live in the valley shown in the upper third of the image. It's a wonderful landscape and I love beeing here ... but it's not easy to capture DeepSky images.

All the best to everyone,
CS Frank

unfortunately good deep sky nights here in our valley in the Alps are rare. The Alps being the European weather divide, are a great barrier between south Europe and central/north Europe where the big weather systems collide and mix, yielding strrong and bumpy winds, wind shears and severe  turbulences.

Ah, I see. Then yes, a wasted night is not a great idea.

Concerning the Antlia Triband RGB Ultra I cite from the maker's website:
"different from other ultra-narrowband filters, it is able to capture galaxies, reflection nebulae"
"It is workable to shoot galaxies, reflection nebulae and star clusters."

As for this, I had looked at the site of artesky.it, an Italian dealer, as a reference.
t states Consigliato per: Ridurre l'inquinamento luminoso, Aumentare il contrasto per le nebulose ad emissione, Risparmiare tempo di elaborazione" which translated to "Recommended for: Reduce light pollution, Increase contrast for emission nebulae, Save processing time'.

It was my mistake not to check the manufacturer's website directly!

CS!

F.T.

Hi all,

just a proof of concept for the use of the Antlia Triband RGB Ultra filter on the WitchHead nebula. This is only 1h20' integration time. In addition damp and foggy air flowed in, as obviously visible at the big star Rigel.

So I can answer my own question which I posted to start this thread: The Antlia Triband RGB Ultra is capable to capture reflection nebulae like the WitchHead nebula.

This result is .... well ... rather ugly. I hope to collect at least 4 hours of photons from this target to hopefully get a more pleasing result.

This image was taken with the ZWO ASI533MC Pro + Samyang 135mm @ f/2.0 + 34x180s + Gain 100 + Bias 1 + -10°C.

CS Frank

I am not sure  of your conditions, but I just photographed this from my Bortle 3/4 zone.  My problem is that it is low in the Southern sky, and I have hills that obscure my Southern Horizon.  This led to less integration time than I would like.  I did use an IDAS LPS D3 filter which may have similar bandpass characteristics as the Antila Tri-Band.  Give it a try, and see what you come up with.   I would recommend 5-minute guided and dithered  subs, and possibly 3 to 10 hrs of integration time.  Here is a link to my image.

https://www.astrobin.com/rkk3z7/

Timothy Straub:
I am not sure  of your conditions, but I just photographed this from my Bortle 3/4 zone.  My problem is that it is low in the Southern sky, and I have hills that obscure my Southern Horizon.  This led to less integration time than I would like.  I did use an IDAS LPS D3 filter which may have similar bandpass characteristics as the Antila Tri-Band.  Give it a try, and see what you come up with.   I would recommend 5-minute guided and dithered  subs, and possibly 3 to 10 hrs of integration time.  Here is a link to my image.

https://www.astrobin.com/rkk3z7/

I looked up your place (Prosser) in Google Earth 3D out of curiosity: Prosser is at ~46°N (200m MSL) with dry hill barrier (~500m MSL) in the south, on top and behind of which are extended dry lands.

My place is at 47.5°N at 680m in an alpine valley, which is only about 1+ km wide and surrounded on three side with mountains up to 2962 m. The mountains are covered with extensive mixed forests (deciduous and coniferous) up to an altitude of 1850m. There are many alpine meadows, torrents from the mountains and a river in the valley.

It is so green here for a reason: All weather systems (esp. low pressure zones with clouds, storms, rain / snow) from SW > W > NW > N > NE crash against the Alps and all precipitation falls here.

I love my home, here in the mountains: climbing, hiking, paragliding, mountain biking, rafting, skiing, cross country skiing ... there are endless options to have beautiful times outdoors.

~ * ~

For (deepsky) AP this ist certainly not a very good place: Very limited horizon due to surrounding mountains and usually very high humidity - mostly 80%-90% - which yields bad seeing, together with wind shears where the three valleys meet and gusty, turbulent winds due to our local micro climate.

>>>   See this tidal cloud / fog animation at my place   <<<  and mind the timestamps!

In winter nights, the WitchHead nebula is in view from Az=160° at Alt=32°, with an altitude of 34° in the meridian and only 28° two hours past the meridian. Then the mountains on the western side of our valley come into the imaging field.

So, at best I could capture NGC1909 for ~3 hours ... if a good night would decide to stay clear and cloud- / fogless. :-)