Caldwell 49 - The Rosette Nebula

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gboulton
Posts: 122
Joined: Thu Dec 06, 2012 12:40 am

Caldwell 49 - The Rosette Nebula

Post by gboulton »

Image

  • ED80T CF on a HyperTuned CG-5 Mount
  • EOS 450D
  • HoTech HCA Field Flattener w/ Baader 2" Nd Skyglow filter
  • 24 x 300" Lights at ISO 400
  • 10 Bias
  • 10 Flats
  • No darks, PHD Dithering
  • BYE Session management
  • PHD Guidance through Orion 50mm Guidescope and Orion SSAG
  • Post process in /r/StarTools, final color adjustment in PS CS2
  • Shot from a Red zone just outside of Nashville, TN
  • Full tech card and link to TIF at astrobin
-- Gordon

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admin
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Re: Caldwell 49 - The Rosette Nebula

Post by admin »

Nice!
Spotted it on Reddit :)
I took the TIF and put it through the 1.3.208 Maintenance Release (slightly better color calibration in the Wipe module for noisy images) and ended up with this. I've found that the Wipe module had been to conservative when correcting the background on noisy images, leaving too much light pollution in some cases - this makes color calibration harder in those images. I'm now using a more aggressive filter. The only trick really now is to use a large Dark Anomaly filter setting in the Wipe module - makes it less susceptible to noise.
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Ivo Jager
StarTools creator and astronomy enthusiast
gboulton
Posts: 122
Joined: Thu Dec 06, 2012 12:40 am

Re: Caldwell 49 - The Rosette Nebula

Post by gboulton »

Reprocessed with Ivo's help on Reddit.
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Muuuuuuuuch improved. Thanks, Ivo! :thumbsup:
-- Gordon

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Gasman
Posts: 25
Joined: Wed Jan 30, 2013 12:05 pm

Re: Caldwell 49 - The Rosette Nebula

Post by Gasman »

Hi guys
It would really help us newbs if you could include a quick (?) step by step how you process your images :-)
Thanks
Steve
PS lovely image BTW
gboulton
Posts: 122
Joined: Thu Dec 06, 2012 12:40 am

Re: Caldwell 49 - The Rosette Nebula

Post by gboulton »

Gasman wrote:Hi guys
It would really help us newbs if you could include a quick (?) step by step how you process your images :-)
Thanks
Steve
PS lovely image BTW
Thanks, Steve!

And you're right...we really should, since not doing so kinda defeats the whole point of having a gallery on the ST site, eh?

For this one:
  • Bin to 50%
  • Cropped 20px per side
  • AutoDev to see what's there.
  • Wipe -> Vignetting mode, used Dark Anomaly Filter (I forget how much..probably middle of the range somewhere)
  • AutoDev again, using Ignore Detail, probably around 3 px or so
  • Sharpen, using low settings for the smaller stuff, to mostly just sharpen the larger nebula
  • Life->Isolate mode. I played with saturation and amount to get something I liked.
  • Contrast - I just toy with the DAF and strength until I like the results.
  • Stop tracking, did noise reduction...probably used a "lighter" amount than the defaults, knowing me.
  • Color module. Bumped up Blue and Green ratios to try to kill off some of the Red tone. Probably capped Green as well.
  • Then I used a trick Ivo taught me on Reddit. i used the layer module to "undo" the color adjustment to PART of the image...in other words, making it non-linear. Some parts got more saturation/color than others. In the layer module, you can play with the mask mode to replace the background adjustments with the foreground adjustments, or vice versa. In this case (And I'm copying what Ivo suggested here, since I don't remember the exact settings) it was : Layer Undo->Background Parameter [Brightness Mask Mode] set to [Where fg is dark, use bg] Parameter [Brightness Mask Power] set to [4.20] I tweaked/played with the numbers and sliders, but that's the basic idea.
  • Used a star mask to bump the star colors and saturation in the Color module.
  • Used the same mask to do a Repair on the stars, and tighten up any slightly oblong ones.
I think that's probably pretty close. I may have forgotten a step or two in there (It's been a few days...and I deleted the ST log) but that's the basic idea.
-- Gordon

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Gasman
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Re: Caldwell 49 - The Rosette Nebula

Post by Gasman »

Thanks Gordon,gives me a guide to work to :-)
Best
Steve
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