First NB Colour Image NGC3372

[barx1963]

Hi all
This is the result of 3 nights data this week.
Consists of:
Ha 12x5mins
OIII 13x5mins
SII 11 x 5mins

Scope: Stellarvue SVR102T with matched SV field flattener at f7
Mount: Atlas AZEQ-G
Guiding: PHD2 with Orion SSAG Pro and Orion ST80
Camera:SBIG STT8300M with integrated guider and filter wheel, Baader narrowband 36mm filters (integrated guider not used, still figuring that out!)
Capture: SGP
Processing: Pre processed in Pixinsight with final integration of colour channels and a little bit of processing in PS CC2017. I have also included a starless version for a bit of fun! Colours as per Hubble palette.
Still learning processing beyond very basic stuff. Think I need to work out star masks in PI so I can get combinations there under control and not have the oversaturated stars I am getting here. Anyway, pretty happy at this stage.

Malcolm

[Benjamin]

Haven't got the experience to say anything except that it looks beautiful. All those smokey limbs, clear dusty outcrops and all that clarity around the central star.

[glend]

Malcolm nice start with Eta C. You colour balance is a nice compromise. At f7 you could probably do with slighly longer exposures with that camera, or more subs, but it is a bright target and too often the core can be blown out.

[jarrod_koh]

My comments echo Bens! I have minimal experience but I'm liking what I see and would like to attempt this one day!
Thank you for sharing!
:thumbsup::thumbsup:

[barx1963]

Thanks Glen
I have taken few 10min subs in Ha, so may try to get some more soon. I have another 30mins on each filter also that I collected last night so will integrate those soon.

Cheers

Malcolm

[DarkKnight]

Hi Malcolm,

A most impressive image with great clarity and detail. Well done. :thumbsup:

I'm very new to Astrophotography so I apologise in advance if my question is a dumb newbie one.

When I look at your image on my calibrated monitor it's as sharp as a tack but all the stars, other than the core, appear to have CA. I don't really know what colours the night sky has or how subjective PP is so I look at NASA pics to try to get a ballpark idea.

Is the CA normal (?) or is your post a work in progress?

[rcheshire]

Looking very professional Malcolm. You have really taken to this imaging thing.

[barx1963]

Not sure about that Rowland, makin' it up as I go long.

Malcolm

[rcheshire]

Don't we all...

[SimmoW]

Great start Malcolm! Doing great to be onto NB so early. Yes it can be a *****!

Have you tried using the SCNR process in PI to remove any green from your image? That often fixes things heaps

[barx1963]

Kev
Very much a work in progress. Stars have a magenta halo, which apparently is common with combining narrowband images. There is a script that can be used in Pixinsight to fix it but struggling to figure it out at the moment.

Cheers

[DarkKnight]

Hi Malcolm,

Hope you don't mind but as part of my learning process I downloaded your shot and had a play with it in CS6.

I was able to pretty much get rid of the magenta halos in three processes. First in 'Lens Correction' and then in Camera Raw and Selective Colour. Fiddly, but it seemed to get the desired result.

Being very new to this genre I googled NGC 3372 to get an idea of what it's overall appearance looked like. Wow, I know each shot will be different because of seeing variance and post processing, but it seemed like every colour of the rainbow was deemed as the dominant colour.

Other than the halos I found almost no red in the shot so I will be interested to see how your further Ha integration goes.

Oh, and if I sound even vaguely like I know what I'm talking about, I don't.

Cheers

Kev

[RickS]

Hi Malcolm,

The magenta halos result because the Sii and Oiii data normally needs a lot more stretching to match the Ha. This bloats the stars in red and blue and the combination is magenta.

Did you figure out how to use ColorMask to reduce the halos?

Cheers,
Rick.

[barx1963]

No Rick, still having issues. Not sure what I am doing wrong at this stage. Am going to have another try later this week.

Malcolm

[RickS]

If you want to put a FITS or XISF file on Dropbox or similiar I'd be happy to have a go at a quick process and send you the process icons. PM me if interested...

[DarkKnight]

Hi Malcolm,

My quick fix to reduce the purple halos.

Photoshop > Image > Adjustments > Selective Colour > Red > reduce Magenta and increase Cyan to taste.

It doesn't reduce the halos per se but it does reduce the colour cast. And I'm pretty sure that every star in the shot is not pearly white.

And if in my naivety I'm oversimplifying the process I apologise for sticking my oar in.

Here is my result with a quick 'n' dirty sharpen with 'Sharpen More', a tool that I've never used before but for some reason seems to work on this image.

Cheers

Kev

[RickS]

Hi Malcolm,

Got the files and did a quick & dirty process. I tried to PM you the location of the project but your mailbox is full. I sent you an email via the forum instead...

Cheers,
Rick.

[barx1963]

Had a bit more of a play with this one. Still working on the PI process, but decided to just crack into it with Photoshop. Tried Kev's approach and did some HLVG and some mucking about with Annies Actions.

It is a big files so this is pretty knocked about by compression artifacts so don't look too closely!!

Malcolm

[DarkKnight]

Looking better Malcolm. :thumbsup:

As I'm sure you are aware there are eleventy zillion different outcomes you can achieve with PP in CS6.

For me it starts with your WB setting, and finishes when YOU are happy with the result.