Rick,
I ran BackgroundNeutralization, balanced colour and DBE on my combined image. Unlocking the STF yielded the minutest change in star colour, so, my colour balance should have been pretty spot on.
What I might try doing is a DBE on each channel before running LinearFit. I understand that it is often best to LinearFit to the channel with the lowest signal, otherwise you run the risk of increasing noise if trying to fit low signal channels to high signal ones. Makes sense. So, this time, I will try to fit to SII instead of OIII. At any rate, it can't hurt to try.
If you can email me a copy of your script to my email, I'd appreciate it. I'll send you a message on spacebook.
Many thanks for your detailed reply.
Quote:
Originally Posted by RickS
H,
The choice of LinearFit reference can make a difference but I haven't found a way to predict the best choice. I usually just pick one at random and work with the result.
A green bias is very common even after a LinearFit. DBE or BackgroundNeutralization will go a way towards fixing it. After a stretch I normally use the ColorMask script (not part of the standard distribution yet but you can get it on the PI forum or ask me for a copy) to do something equivalent to the Bob Franke method for PS ( http://bf-astro.com/hubblep.htm). Colour masking is actually more powerful than PS selective color because you can apply a range of tools to the masked image.
Removing the stars from the colour image (keep them in the synthetic luminance) works really well too. That's the core thing I took from JPM's tone mapping. It gets rid of those horrid magenta stars  It also allows you to do heavy noise reduction and a much bigger stretch on the weaker NB filters to get a lot more latitude with colour adjustment.
Cheers,
Rick. |
Tim,
Thanks, sir. Glad it appeals to you.
Quote:
Originally Posted by topheart
Hi Humayun,
I really like the image. Well done!
The colour scheme creates a unique feel to the image which appeals to me.
An interesting discussion also ...thanks!
Cheers,
Tim
|
Rom,
Thanks, mate. Can't wait to post the final rendition soon!
Quote:
Originally Posted by el_draco
What a fabulous short. Looks almost 3D. Just beautiful  |
Mike,
Thank you, very much! I paid a great deal of attention to the centre/brightest areas (after 60 hours of exposure, it was quite bright and was very conducive to bringing out the fainter structures by bringing the midtones down).
Quote:
Originally Posted by Placidus
I displayed your excellent image to SHO because that's what I'm familiar with. It looks great. Regardless of mapping, there is exquisite depth and detail. Good judgement call on the balance between the faintest and brightest structures, leaving excellent mid-tone contrast. Lovely composition too. Fantastic work.
Best,
Mike |
Thank you, one and all.
H
