Ngc 1955,2004,2020,2040

[ozstronomer (Geoff)]

I thought these objects looked interesting so I collected the RGB at a dark site and several hours of Ha and O111 from home for an NBRGB image.

I used Pixinsights NBRGB script to blend 60% Ha and 200% O111 with the RGB.

Not sure if the colours balance together, I suspect I need more O111 as the blue looks a little washed out.

Taken with W.O FLT110, Moravian G2-8300;

2 hours each R,G,B (5min subs) 3 hours Ha; 4.5 hours O111 ( 10min subs)

I had several attempts at blending the Ha and O111 to achieve the final result.

Processing comments welcome

Large Image here... http://www.astrobin.com/158578/

Geoff

[batema (Mark)]

Looks full of activity in there Geoff. Are you off to astrofest this year?

[ozstronomer (Geoff)]

Hi Mark, I'll be there for most of the time. I'll be interested in checking out some of your new kit.

[alpal]

Hi Geoff,
Looking good & on it's way to a very nice image with a lot more work.

"Processing comments welcome"

Possible improvements? - some ideas:
Maybe use star mask on all 3 channels right from the start of processing to keep the star sizes down -
maybe even make a starless version with "content aware & fill"
in Photoshop & add the stars later.
Also looks like it needs more careful stretching to obtain greater detail
of the small brightness changes in the nebula areas.
It could also be over smoothed in the nebula areas - I'm not sure.
Did you stretch the FITS stacks in 32 bits?
NASA FITS Liberator is great for that & it's free.
I would also play around with "selective colour" in Photoshop to see what pops out.

cheers
Allan

[Andy01 (Andy)]

Originally Posted by alpal

maybe even make a starless version with "content aware & fill"
in Photoshop & add the stars later.

Pardon the hack Geoff, but maybe Allan can teach us both something here - Allan, can you explain more about how that technique you mentioned is done/works with PS?

Great choice of subject Geoff, one of my favourites

Andy

[alpal]

Originally Posted by Andy01

Pardon the hack Geoff, but maybe Allan can teach us both something here - Allan, can you explain more about how that technique you mentioned is done/works with PS?

Andy

Sure - right here:

http://www.astro-photography.net/Star-Removal.html

Note - if I press delete on PS CS5 it doesn't work as per the tutorial.
I just need to select the stars & click: edit, fill.
The stars magically disappear.
(If some are still there you can use the healing brush tool to get rid of them.)

They can then be copied & pasted back in later from a partially stretched
version that was saved on your HDD.
That way they remain undamaged & still have colour.


cheers
Allan

[Andy01 (Andy)]

Originally Posted by alpal

Sure - right here:

http://www.astro-photography.net/Star-Removal.html

Note - if I press delete on PS CS5 it doesn't work as per the tutorial.
I just need to select the stars & click: edit, fill.
The stars magically disappear.
(If some are still there you can use the healing brush tool to get rid of them.)

They can then be copied & pasted back in later from a partially stretched
version that was saved on your HDD.
That way they remain undamaged & still have colour.


cheers
Allan

Thanks for posting that link Allan- tried it today - a bit fiddly (all ST removal techniques seem to be) but a nice smooth result!
Cheers
Andy

[Spookyer (Brett)]

Geoff, plenty of action going on in that one mate!

Brett

[ozstronomer (Geoff)]

Thanks Allan, ill have a look at that star removal web site

Thanks Brett, yep a nice piece of sky, still trying to get the best out of the data

Geoff

[alpal]

Originally Posted by ozstronomer

Thanks Allan, ill have a look at that star removal web site

Thanks Brett, yep a nice piece of sky, still trying to get the best out of the data

Geoff

No worries Geoff,
It's a good technique when the nebulas are small & the
background is too busy with many stars overpowering the image.
You can always put a pre-stretched version of the stars back &
they will then be much diminished - but the nebulas will stand out!

cheers
Allan

[RickS (Rick)]

Lots of great stuff in that FOV, Geoff! Hard to comment on the processing too much without knowing what the original data is like. If you like, I'd be happy to have a quick go at it in PI and give you a project with the history included.

Allan: it's rarely necessary to remove stars for LRGB processing in PI. I usually just protect them with a mask during operations that could have a deleterious effect. About the only time I remove them is for tone mapped NB processing, and even then it is more of a convenience than a necessity.

Cheers,
Rick.