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View Full Version here: : Rain, Steam and Stars - IC 4628 in NB


Andy01
01-07-2016, 07:09 PM
The swirling clouds of S2 & Ha here remind me of JMW Turner's famous landscape painting, "Rain, Steam & Speed".

I was surprised to see that there are some happy coincidental compositional elements as well.
Turner must have been in my sub-concious when I was framing this one up!

I am surprised by how much Ha & S2 surround this neb, the nebulosity seems to on forever.
It was nice to revisit this region again with the new widefield 'scope to fit most of it in.

7 hrs x 1800secs Ha 5nm
5 Hrs x 1800secs S2 5nm
4.5Hrs x 1800 secs O3 5nm
Processed in Startools, PS6 & Nik filters

High res Here (http://www.astrobin.com/full/252457/B/)

Thanks for looking, taken from my backyard in Melbourne, Australia over 4 nights.

strongmanmike
01-07-2016, 07:30 PM
Another interesting take on an ol favourite Andy ;) Perhaps a little two tone for a three filter NB image and the blue looks to have hard borders ..?..but overall looks good still, love the long tendrils of gas stringing off to the left, nice work Mr Artiste :painting: :thumbsup:

Mike

Atmos
01-07-2016, 08:59 PM
Certainly is a lot of nebulosity in the area Andy! I'd love to have your FOV for regions like this :)
I like the colour scheme, I just like seeing the universe on fire ;) Mike is correct with the representation... But let it burn muahahaha!

What I REALLY want to know is where these four clear nights in Melbourne were?

Placidus
01-07-2016, 10:31 PM
Hi, Andy. You've done a wonderful job of capturing the outermost and faintest streamers of nebulosity. Both the Flying Dutchman title and the Rain Steam Speed metaphors are fully justified. The two open clusters add interest also.

It looks a bit like you've combined the H-alpha and SII into a single channel, which has then been mapped to an orange-red.

Andy01
02-07-2016, 10:01 AM
Thanks Mike. The Ha and S2 emissions here appear similar in BW, but subtly different.
I didn't want to use the usual HST palette, so I've chosen to use a colour palette that aligns then in a colour complimentary manner.
The main difference being the shift of Ha = green to Ha = orange.

Blame it on my inbuilt artistic DNA :D Salut!



Thanks Colin, I recommend using Cloud Free Nights for predicting those pesky clouds?
It's accurate, free and the author is an ASV member :thumbsup:
http://www.cloudfreenight.com/map.view

As to colours etc, anything goes in Love & Narrowband, depends on the authors intent I guess ;)




Thanks M&T, it's a much more detailed region than I originally thought, so much nebulosity to capture.
Ha, S2 & O3 remain in separate channels, but tweaked in PS & NIK to align as S2 = Yellow and Ha = Orange & O3 = Blue, instead of the more traditional HST.

I've commented previously that this NB stuff is pretty subjective, depending on one's intent.
Matts Spore Astrophotography has an interesting take on this with some good examples that are worth looking at ...http://www.istarion.net/Picturepages/Nebulas/NGC7380%20The%20Wizard%20Nebula.sht ml

As always, thanks for your feedback everyone :thumbsup:

RickS
02-07-2016, 03:47 PM
Great image, Andy! It does look like a bi-colour, but a very nice one :thumbsup:

Placidus
02-07-2016, 05:12 PM
Hi, Andy,

Thanks for posting the separate Ha and SII. I agree totally with your comments and observations. I went back and had a look at our shot of the same area, making a bicolour Ha/SII shot, and being careful to process them linearly so I didn't introduce any false differences with curves. They are indeed remarkably similar, except perhaps in the very faintest regions, and that could be just limits of knowledge about the zero point.

Best,
Mike

Andy01
03-07-2016, 09:18 AM
Cheers Rich, much appreciated :thumbsup:



Cheers Mike, Appreciate your investigative research :thumbsup:
Sorry but I didn't quite understand... You mean you reprocessed your original image, or that's how you processed it originally?
Maybe post a link?
Cheers :)
Andy

Placidus
03-07-2016, 09:35 PM
Sorry, Andy. As a result of your suggestion, we reprocessed even more carefully, and decided we were quite wrong. There really is quite a strong topographical separation between H-alpha and SII. We've posted the image and the method separately. Mega-thanks for making us have a closer look.

Best,
M & T