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The Pelican Nebula


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Derbyshire Dave
34 minutes ago, Clive said:

Nice image Dave. Out of interest, what proportion of each NB did you allocate to RGB?

Hi Clive, thanks.

  I intended to have the same number of ten minute subs for the Oiii, and in fact I did take them, but at the stacking point I realised that one of those darned gremlins had got in, and though the shots were good, they had moved significantly.

 

  So i backtacked to a previous evening to grab the 5 minute exposures which were in the right place. I allocated all of subs 100% to each of the R,G and B. The blue (Oiii) had a lot less area under the graph, so I stretched that more, and in fact reduced the green (Ha) until the area under each graph of each was about the same.

 Then applied the hubble action and went from there

 

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Thanks Dave, I was interested due to the complete lack of green in your image (a good thing in my opinion 😊). I've seen reference to a 'Hubble' pallette where Ha is transformed to 'beige' (roughly equal R and G), O3 to 'cyan' (roughly equal  G and B) and S2 to 'white' (equal RGB) so I wondered if you had used something similar.

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Derbyshire Dave
1 hour ago, Clive said:

Thanks Dave, I was interested due to the complete lack of green in your image (a good thing in my opinion 😊). I've seen reference to a 'Hubble' pallette where Ha is transformed to 'beige' (roughly equal R and G), O3 to 'cyan' (roughly equal  G and B) and S2 to 'white' (equal RGB) so I wondered if you had used something similar.

Thanks Clive. My process used to involve using the HLVG (Hasta La Vista Green) to subdue green. But I find it’s better to just balance the areas under the graph.

 

HLVG is very useful though, to get rid of ‘magenta stars’. If you find, as I do sometimes, that your processing leaves your stars with a magenta tinge and halo, invert the image. Magenta becomes it’s complement, I.e. green, and you’ll see green stars and halos. Run HLVG, the green goes. Re-invert your image and your magenta stars have gone. 

I was tempted to say ‘voila’ there but that would have been just wrong.... 😅

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