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DaveS

Melotte 15 23 hours.

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This is 12 hours [OIII], 9 hours [SII] (Need more), and 4 hours H-alpha which is very strong here. All in 10 min subs over many nights after M27 got too low.

130 f/7 apo, Astrodon 3nm, ASI 1600, encoder guided on DDM60.

Stacking in AstroArt 7, initial stretch in GIMP, back into AA7 for RGB synthesis, cropping and gradient reduction, then into Affinity Photo for channel mixer to get rid of the excessive magenta (Still a bit there), selective colour, noise reduction and clarity. JPEG export in AA7.

488135001_SHO9412AffinityFull.thumb.jpg.d30b397233c9817b9d063efe2077b085.jpg

C&C welcome, as usual.

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Excellent work Dave, lovely range of colours.

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Thanks Mark. There is a touch of trailing in RA which I need to get rid of. May try Goran's layer method in GIMP.

Looking at my files, this was over 11 nights.

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Very nice image of one of my favourite areas.

Hope you don't mind but I took the liberty of removing the magenta halos. I probably didn't use the best approach but they've gone and I don't think it has changed the rest of the image.

Adrian

 

 

minus_magenta_stars.tiff

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Great image Dave, to echo Mark's comment on the colours - big range to look at, the more you study it.  Lots to like about the 1:1 view too.

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Ah yes, much better. I could see that some stars were still a bit magenta, but was worried about pushing it too far and bringing too much green in.

What method did you use?

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21 minutes ago, DaveS said:

What method did you use?

I'm afraid I used the "cheating method". I took the image into PixInsight, inverted the image and applied the SCNR process normally used to reduce green in an image. I then reinverted the image and the magenta halos have been removed. I am sure there are fancy methods involving PixelMaths and masks and all manner of things but the cheat method seems to work and I honestly can't see it has changed anything else.

Adrian

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Ah, I thought it involved PI. It might be a cheat method, but it worked, so that's OK by me.

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4 minutes ago, DaveS said:

Ah, I thought it involved PI.

I suppose in principle something similar ought to work in any photo package - invert the image, reduce the green, reinvert the image. Because I have PI I take the easy approach but I might have a go in PS or Affinity and see if the same result can me emmulated.

Adrian

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Pixinsight Pixelmath has a very simple formula to remove magenta from the edge of stars: https://pixinsight.com/forum/index.php?threads/using-pixelmath-to-get-rid-of-magenta-stars-in-sho-hubble-palette-narrowband.7128/

 

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Very nice indeed Dave,

Funny thing is i didn't even notice the magenta stars,

More to the point, personally i do not  find them intrusive especially on 

a false color image.

But then beauty as they say is in the eye of the beholder.

I admire your long slog on this target, and its paid off

Well done

Paul  

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5 hours ago, Adreneline said:

I'm afraid I used the "cheating method". I took the image into PixInsight, inverted the image and applied the SCNR process normally used to reduce green in an image. I then reinverted the image and the magenta halos have been removed. I am sure there are fancy methods involving PixelMaths and masks and all manner of things but the cheat method seems to work and I honestly can't see it has changed anything else.

Adrian

Seems a bit labour intensive for such a simple thing..lol..

My method: load into photoshop, call up saturation, select magenta, move slider left to remove magenta.... done   :D

 

 

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I pulled the TIFF into Affinity, went into Channel Mixer, Mode CMYK, Magents, and reduced the Magenta slider. Possibly I could have gone a bit further but I was concerned about increasing the green too much.

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55 minutes ago, Uranium235 said:

Seems a bit labour intensive

Haha! I'm retired so I need something to help fill the time between brushing up on quantum physics and sleeping ;)

 

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