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Old 27-07-2010, 10:16 PM
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rally is offline
Join Date: Sep 2007
Location: Australia
Posts: 896

I think 50% Ha for luminance is possibly pushing it a bit high - the problem is that the recipe is different for different subjects, so its definitely not a one size fits all.

The Ha data shows all the nice detail so its very tempting to try and use it to the max.

I would be experimenting from 20-40%
I recall doing the same thing and dropped Ha right back and blended it with normal L, it ended up with around 25%.

Of course there is always the method of removing the stars and then adding them back in again later after you have tweaked the nebula !
Don't laugh - it does work.

Most of your stars are white in the centre with blue halos, so I am wondering if you clipped your stars during the stretching process at an earlier point while keeping an eye on the nebulosity.
The fact that you are pushing blue and green and boosting red to get rid of the pink is possibly a major contributor.
The Salmon Pink comes about as a result of adding Luminance and losing saturation not because you actually lost Red, thats byproduct of working in RGB colour space.

Controlling your stellar profiles to correct for colour distortion in processing by using DDP stretches for both RGB and L (or HaL) separately will help keep your stars their natural colour, but adding Ha afterwards is yet another process to be careful of,
So just wondering what the stars were like before you added the Ha ?

What was the FWHM of your LRGB and Ha images - could it be that some (eg B and G) were larger than the others ?


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