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[RCC] Leo Triplet in HaLRGB

Russell Croman Astrophotography NoiseXTerminator Russell Croman Astrophotography BlurXTerminator Russell Croman Astrophotography StarXTerminator Processing Request for feedback
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James Markgraf avatar
James Markgraf avatar
I'm just getting started with mono imaging and the processing that goes into it and would appreciate feedback.

Process:
  • Stack and align with WBPP
  • Graxpert
  • StarXTerminator to remove the stars
  • Clone stamp to clean up the one dust mote that no amount of flats seems to remove (I've gotta pull my camera to clean the sensor window)
  • Pixel math to bring the stars back in
  • Channel combination to create the RGB image
  • Background normalization
  • Color calibration
  • BlurXTerminator
  • StarXTerminator on Ha and RGB
  • SetiAstro's Continuum Subtraction script for Ha
  • SetiAstro's Star Stretch script on the stars only image
  • SetiAstro's Statistical Stretch script on the starless images
  • Curves transformation on RGB
  • Curves transformation on Ha
  • Curves transformation on Lum
  • LRGB combination to add L to RGB
  • Combine H-Alpha script to bring the Ha in to RGB
  • Some more curves to address the background a little bit
  • HLP's Stars Back script to bring the stars back in
  • NoiseXTerminator to clean up
  • SetiAstro's signature add script (forget the name off the top of my head)
  • GIMP to shrink the image down a little from its original size (96 MP after drizzle integration!)


This workflow is based on a SetiAstro YouTube video that I found works well for me. I know I could use SPCC instead of Color Calibration but I had some funky issues with getting the astrometric solution on my image, so I skipped that for now. I also know I'm using a lot of scripts instead of using the processes behind them, but, aside from Continuum Subtraction, I could replace most scripts with the underlying processes if the scripts went away.

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Scott Stirling avatar
Scott Stirling avatar
After drizzle integration it is I think normal to resample the resulting image back to its original dimensions, which reveals its improvement on factors such as FWHM, noise and Eccentricity.

Looks good.  There’s a lot more data to be captured there because that area has a lot more stars and IFN and a long tail of stars or dust on the “Hamburger Galaxy.”   Keep at it — Leo is near zenith at a reasonable hour this time of year, get more data and show us how it comes out.
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Rabeea Alkuwari avatar
Rabeea Alkuwari avatar
Things that can improve your image:

1. replace LRGB combination with Imageblend script - this way u will have more control on luminance/color blend
2. SPCC, if you have issues applying it i always apply SPCC pre strech and it always seem to work
3. learn GHS to stretch ur images - it will give you more control on what u want to display in terms of signal. Displaying hamburger galaxy’s tail is a bit challenging but to me it was only achievable using GHS
4. HDRMT post stretch (on lum image) can show lots of detail on galaxies- make sure u have lum mask option on and play with layers to your taste
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James Markgraf avatar
James Markgraf avatar
Scott Stirling:
There’s a lot more data to be captured there because that area has a lot more stars and IFN and a long tail of stars or dust on the “Hamburger Galaxy.”   Keep at it — Leo is near zenith at a reasonable hour this time of year, get more data and show us how it comes out.


I actually got some more lights the other night, so I'm going to try to up my total exposure time and see what I get. Being so close to Philadelphia, light pollution in my area is HORRIBLE. I'm on the verge of being Bortle 9, so I try to keep my exposures relatively short and just take as many as I possibly can.

I'll try resampling after everything is said and done and see how it looks. Thanks for the input.
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James Markgraf avatar
James Markgraf avatar
Rabeea Alkuwari:
Things that can improve your image:

1. replace LRGB combination with Imageblend script - this way u will have more control on luminance/color blend
2. SPCC, if you have issues applying it i always apply SPCC pre strech and it always seem to work
3. learn GHS to stretch ur images - it will give you more control on what u want to display in terms of signal. Displaying hamburger galaxy’s tail is a bit challenging but to me it was only achievable using GHS
4. HDRMT post stretch (on lum image) can show lots of detail on galaxies- make sure u have lum mask option on and play with layers to your taste

I'll have to check out the ImageBlend script. I never even thought to look to see if there was one available. I skipped SPCC at the time of this image because I had some issues with plate solving the image. I think that perhaps there was an issue with my GAIA catalog because I reloaded a fresh copy and my solving is working again, so I'll definitely give SPCC another shot. I've been playing around with GHS a bit but still not quite there in terms of comfort level (I seem to have a heavy hand sometimes). I have not played around with HDRMT so I'll definitely give that a go.

I am going to re-stack my images since I have more lights to add. I'll incorporate your suggestions into the process and see how it goes. Thanks for the input.
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