Author Topic: Narrowband Workflows  (Read 4277 times)

Offline kayronjm

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Narrowband Workflows
« on: 2016 September 08 12:36:07 »
Hi all,

It's been a while since I've dealt with narrowband imaging and though I'm fairly comfortable with the tools used, I wonder whether someone here has insight into how to perhaps replicate Photoshop's power of layers when it comes to narrowband colour palette.

Sara Wager is very well known for her absolutely fantastic work in astrophotography. She uses Photoshop for the vast majority of her post-processing. This is one example of a narrowband image of hers that I particularly like: https://www.flickr.com/photos/swag72/14989972842

In my experience with narrowband images in PixInsight, it is very hard if not near impossible to achieve that level of intensity in the colour palette. PixInsight is very data-driven, which means that when you combine the HA and OIII data, the inside of the North America Nebula appears mostly white, as both combine as such. This is using the same Cannistra Bicolour Palette technique as Sara's, but in PixInsight. The difference is, of course, that Sara uses Photoshop and is probably able to layer the image and colourise parts of it according to the data, as she sees fit. To date, I've been unable to replicate such an end result (or even anything close to it) in PixInsight, even using hue shifts with CurvesTransformation. Neither with HA and OIII alone, or with HA, OIII and SII.

My question is very open, really. What kind of narrowband workflows do people use and is there any general workflow that allows one to produce narrowband images as intense and as contrasting (in colour) as Sara's (linked above)? Thank you! :)

Kayron
- Avalon M-Uno
- Takahashi FSQ-85ED, Altair Astro 8" RC with Astro-Physics CCDT67 Telecompressor
- QSI 660wsg-8, Starlight Xpress Lodestar X2
- Astrodon E-Series Gen2 LRGB 1.25", Astrodon HA, OIII & SII 3nm 1.25"

Offline pfile

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Re: Narrowband Workflows
« Reply #1 on: 2016 September 08 14:27:45 »
IMO RickS's colormask script brings whatever techniques people have been using with PS to PI.

sara even commented on one of my NB images that the colors were as she envisioned them (widefield cygnus area) so i suppose i must have done something right in her book using ColorMask and RickS's flow.

rob






Offline msmythers

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Re: Narrowband Workflows
« Reply #2 on: 2016 September 08 15:05:16 »
I agree with rob and if I could add one more tool that works well with these types of images is InterChannelCurves. This is from Carlos Milovic. I find it complements Rick's Color Mask very well. The only downside is it is only available for Linux and Windows systems so if you're a Mac user your out of luck. Carlos has created many wonderful tools. http://www.astrophoto.cl/Research.html


Mike

 

Offline RickS

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Re: Narrowband Workflows
« Reply #3 on: 2016 September 09 02:35:45 »
Thanks for the kind comments on ColorMask, Rob & Mike  :)

Kayron: I may be a little biased but the ColorMask script is now my magic bullet for colour manipulation, especially for narrowband images.  I believe it's actually more powerful than the colour manipulation tools in PS because you can mask a range of hues and then apply the whole range of PI tools, not just a handful of pre-canned manipulations.  As Mike mentioned, other tools like ICC are also useful and don't forget the power of simple masks.  If you're willing to dig into PixelMath then you can do truly amazing stuff.  Anything I can imagine colour-wise I have been able to do in PI.

Here's one of my funkier attempts at a bi-colour image: http://www.astrobin.com/full/143114/0/

Cheers,
Rick.

Offline lucchett

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Re: Narrowband Workflows
« Reply #4 on: 2016 September 09 04:49:05 »
Kyron,
I don't do NB, only RGB and HaRGB, but I couldn't find a place for those blending modes (except for max(a,b) ) in my workflow.
Rick's Colormask allows me the creation of "surgical" masks that protect very well some areas from the overwhelming ha.

PS: Don't know if you are aware, you can also write what are called  the "PS" blending modes as Pixelmath expressions.
just search the forum for this or google outside.


Andrea

Offline msmythers

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Re: Narrowband Workflows
« Reply #5 on: 2016 September 09 07:14:16 »
For Blending you can also use Gerald's 'Blend' script.
http://pixinsight.com/forum/index.php?topic=7846.msg51939#msg51939
The current version has been translated back to English it appears. It has some unique features. Like Rick's Color Mask you can see the actual PixelMath equation which has helped my knowledge of how to use PixelMath.


Mike

Offline kayronjm

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Re: Narrowband Workflows
« Reply #6 on: 2016 September 09 09:37:19 »
Thank you VERY much for all your helpful replies guys! :) Ironically I already seemed to have RickS' excellent ColorMask 0.7 script installed, but had forgotten it was there. Having said that, I don't remember when or why I installed it but clearly that is the way forward. I will have a play around with it on an image of mine that I'm finishing capturing soon and will post back some results and comments.

Also, thanks for pointing me to the Blend script and InterChannelCurves module. I have downloaded and installed both as well, just in case, though given RickS' example on his thread for ColorMask, I feel confident that is precisely what I was looking for! :) Thank you again.
- Avalon M-Uno
- Takahashi FSQ-85ED, Altair Astro 8" RC with Astro-Physics CCDT67 Telecompressor
- QSI 660wsg-8, Starlight Xpress Lodestar X2
- Astrodon E-Series Gen2 LRGB 1.25", Astrodon HA, OIII & SII 3nm 1.25"

Offline llpastro

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Re: Narrowband Workflows
« Reply #7 on: 2016 September 10 08:00:42 »
Please excuse the novice question.  But InterChannelsCurves is a .dll not a .js.  Do I install the same way or do I simple paste it somewhere?

Larry
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Offline msmythers

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Re: Narrowband Workflows
« Reply #8 on: 2016 September 10 08:11:03 »
Larry

Check this link for installing a new module.

http://www.pixinsight.com.ar/en/docs/36/pixinsight-install-modules.html


Mike

Offline llpastro

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Re: Narrowband Workflows
« Reply #9 on: 2016 September 10 08:47:25 »
Thanks Mike.

Larry
AP 140 Refractor
SBIG ST-10XME
AP Mach 1 Mount
ATS Portable Pier
Tucson, Arizona

Offline kayronjm

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Re: Narrowband Workflows
« Reply #10 on: 2016 September 11 04:59:50 »
Last night I successfully played around with my data and the use of RickS' excellent ColorMask script. Here is my result of IC1396:

https://www.flickr.com/photos/lightvortexastronomy/28969057684/

Thank you again! :)
- Avalon M-Uno
- Takahashi FSQ-85ED, Altair Astro 8" RC with Astro-Physics CCDT67 Telecompressor
- QSI 660wsg-8, Starlight Xpress Lodestar X2
- Astrodon E-Series Gen2 LRGB 1.25", Astrodon HA, OIII & SII 3nm 1.25"