Soul nebula - bi-colour with RGB stars

[cfpendock]

This was an experiment to try a bi-colour image.  The first attempt didn't look very good - much less crisp than the Ha only version, with fairly colourless stars.  So I shot some RGB stars which I think makes an improvement.  But I'm still not sure that the O3 makes a better or more interesting image....

Tak 106ED wide angle, 10x15 minutes O3, 21x15mins Ha, 16x5mins each for RGB, making a total of towards 12 hours total.

Any suggestions for improvement would be welcomed.

Chris 

[johnrt]

It looks like you have some splendid detail there, what method did you use to blend the colour Chris?

[cfpendock]

Thanks, John.  I used a method pretty similar to Steve Cannistra for the bi-colour.  I then removed the stars (which I didn't like), and replaced them with the RGB stars (blend of lighten and screen).  Pity the framing was a bit off....

Chris

[gnomus]

Hi Chris.  I agree with John that you seem to have a wealth of detail there.  The colour is a little unusual, but as this is 'false colour' then I suppose that is a taste thing.  I'm not familiar with the Cannistra technique you used.  Did you try a simple HOO combination?

[cfpendock]

21 minutes ago, gnomus said:

Did you try a simple HOO combination

Thanks Steve. I tried HOO and thought it looked awful.  The Cannistra technique basically uses a proportion each of Ha and O3 to make the green, colourizing them using clipping masks.  (Photoshop I'm afraid....).  I think this method provides a bit more detail than the HOO, because essentially it is H  (OH)  O, and I found much more detail in the Ha than the O3 for this particular image.  I did mess around with the colours because as you say, these are false colours, and I wanted some colour with any extra detail the O3 might bring.  I know O3 should be a kind of blue, but I didn't like it.

Chris

[gnomus]

3 minutes ago, cfpendock said:

Thanks Steve. I tried HOO and thought it looked awful.  The Cannistra technique basically uses a proportion each of Ha and O3 to make the green, colourizing them using clipping masks.  (Photoshop I'm afraid....).  I think this method provides a bit more detail than the HOO, because essentially it is H  (OH)  O, and I found much more detail in the Ha than the O3 for this particular image.  I did mess around with the colours because as you say, these are false colours, and I wanted some colour with any extra detail the O3 might bring.  I know O3 should be a kind of blue, but I didn't like it.

Chris

No worries Chris.  I am certainly no expert.  I will Google that Cannistra thing.  

[cfpendock]

26 minutes ago, gnomus said:

I will Google that Cannistra thing

http://www.starrywonders.com/bicolortechniquenew.html

 

[Davey-T]

27 minutes ago, gnomus said:

No worries Chris.  I am certainly no expert.  I will Google that Cannistra thing.  

Another medical man I believe, also called Steve wooo spooky.

Inventor of the Cannistra method of combining NB images from two filters.

Got a tutorial somewhere if you'd like it.

Dave

[PatrickGilliland]

Can't help with the colour as I am useless at bi-colour images - some nice detail there and structures showing through nicely.

Paddy

[carastro]

Any chance of posting a link to your stacked Ha and Oiii files so we can have a "go" at it.  

I think most people expect white only stars with narrowband, but of course you have the option of adding RGB stars if you wish.

Carole 

[cfpendock]

2 hours ago, PatrickGilliland said:

Can't help with the colour as I am useless at bi-colour images - some nice detail there and structures showing through nicely.

 

Thank you, Paddy.

[cfpendock]

4 minutes ago, carastro said:

Any chance of posting a link to your stacked Ha and Oiii files so we can have a "go" at it.  

I would be delighted, Carole, but it will mean posting around 16MB for the two files.  With my internet speed this would take the best part of an hour.  I'll try it later or tomorrow when it may be less busy.  

Chris

[carastro]

What about linking to Dropbox?  

Carole 

[cfpendock]

And how would I get the files to Dropbox?  I think the problem would be the same.......Try this, if it works.....

Chris

Ha.TIF

O3.TIF

[carastro]

Thanks worked OK, will have a "go" at it.

Carole 

 

[gnomus]

Thank you for posting up your data.  I did a quick and dirty HOO version.  The data is pretty good, but there is quite a dark patch on the left hand side of both stacks.  I had something like this once when I had my OAG prism sticking too far into my image train - but you don't list an OAG.  It could be calibration, I suppose.   I couldn't remove it entirely and I cropped a bit out.  

[cfpendock]

3 minutes ago, gnomus said:

but you don't list an OAG

Sorry - I should have said - OAG with loadstar - and yes - it may have been sticking out a bit too far: - 

But I'm not sure.  In any case, I've since moved the mirror slightly - after  I took these subs.  That's a nice image you've produced, Steve, in no time at all....Pixinsight or PS?  Personally, I prefer a bit more contrast, and it is a bit red for me.  I know, Ha is red....

Thanks for the play, Chris

 

 

[gnomus]

2 minutes ago, cfpendock said:

... That's a nice image you've produced, Steve, in no time at all....Pixinsight or PS?  ...

DBE in PI.  Stretch in PS.  Combination in PS ....

3 minutes ago, cfpendock said:

.... Personally, I prefer a bit more contrast, and it is a bit red for me....

... then I boosted Saturation a bit, since your original image suggested to me that you like things colourful... 

Contrast is a personal thing.  It is very easy to end up with things looking a bit 'unnatural', I find.

[carastro]

There is a some very good data, in the Ha in particular, and the star size difference between Oiii and Ha was difficult to control as well as some nasty halos, but I did my best.  

I felt some of the very fine detail in your original process had been lost  especially around the area of the top right section of the Nebula.

Here is my rendition, probably not in colours that you like, but I thought it showed some fine detail in the capture especially if you enlarge it.

Here is a larger link (I loaded it into my "behinds the scenes" Astrobin).

http://www.astrobin.com/full/283393/0/?nc=user

Carole

 

 

 

 

[cfpendock]

That is fantastic, Carole!  How did you combine the channels - was it the Cannistra method?

I really do need to learn to process!

Chris

[gnomus]

Very nice Carole.

[carastro]

I use the very simple method taught to me by Anna Morris (of Annie's actions), for LRGB, and then for Bicolour, I simply put the Ha and Oiii into either HOO (as I did here), or SHO if doing Hubble Palette, substituting Ha for Red and Oiii for green and blue in your image.

http://www.eprisephoto.com/create-lrgb

I did have to do some jiggery pokery to enhance detail in High Pass filter (without affecting the stars), and blurring of the colour image to reduce the stars and re-layering the Ha on top once again blending as Luminosity, plus various adjustments in selective colour.

Generally when I do High Pass filter, I take a copy of the image and paste it back over the HIGH pass version as this often has an adverse effect on the stars, and then rub out the bits where I want the detail to show through avoiding the stars. 

HTH

Carole 

[carastro]

Quote

Very nice Carole.

Thanks Gnomus

[cfpendock]

20 minutes ago, carastro said:

I use the very simple method taught to me by Anna Morris (of Annie's actions)

Thanks Carole.  Sadly the link is a video which I will have to download and watch sometime - internet speed won't allow direct watching!  But your approach certainly works.

Chris

[gnomus]

No worries Carole.  I used pretty much the method you linked to.  The colours that popped out looked nothing like your result.  You are not witholding your 'secret sauce' recipe, are you?