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SHO Hubble Palette from OSC Dual Band Data

Optolong L-eXtreme ZWO ASI6200MC Pro Processing SHO Deep Sky
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Simon Todd avatar
Simon Todd avatar
Hi Everybody

Ever since moving to an ASI6200MC Pro from a QHY183M, I faced the challenge of creating SHO Hubble Palette based images, until now.  I have been working on this process for a while, and also had many conversations with Shawn Nielsen on this, but my first image came out as near as I can get so an SHO Hubble Palette image, you can see the image here:

Standard L-eXtreme Dual Band Processed ImageSynthetic SHO Version of Dual Band DataI have documented this process in a tutorial that you can read here, I contemplated creating a video, but I prefer to read tutorials rather than watch videos.

Creating Hubble Palette SHO Images from Dual Band OSC Data
I hope the above tutorial helps

Clear Skies
Simon
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Alessio Pariani avatar
Alessio Pariani avatar
Sorry, but I think there is a lot of confusion here:
  • L-extreme allow lights from Halpha and OIII so, just to start, you cannot use properly the name SHO Hubble Palette when the S is missing;
  • L-enhance and other multiband filters which allow SII light to pass, won't let you split Halpha from SII, since both are red and captured by the same pixels (with an overwhelming Halpha component). In this case you can approsimatively split OIII from Hbeta, since OIII is in both G and B channels and Hb just in B)
  • The G channel which you call SII, is in fact OIII signal and you should not use it as Red.

If you want to combine Halpha and OIII to a Hubble look-a-like bicolor palette, I suggest you to:
  1. split R,G,B
  2. call R = Ha
  3. open PixelMath and fuse G and B (OIII is in both) with max(G,B) which create a single image containing the brightest parts from G and B
  4. call the new image OIII
  5. open LinearFit, set OIII as reference and apply on Ha
  6. return to PixelMath and mix as R=Ha; G=(Ha+OIII)/2; B=OIII
  7. go on with processing at your taste
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Simon Todd avatar
Simon Todd avatar
Hi Alessio

I tried your workflow but it did not work for me whatsoever, it resulted in a very "Blue" casted image and very faint, the LinearFit of the Ha image by source of OIII makes the Ha Image very Dim indeed as you can see below the resulting colour image, as I stated in my post "As near as I can get to an SHO Image", and I do refer to my SHO Image as a "Synthetic" SHO Image

I totally agree with your comment on the SII being missing, hence why it is a Synthetic SHO Image, because the SII has had to be Synthesized

Alessio Pariani avatar
Alessio Pariani avatar
Simon this is just the starting point. as stated in the last point of the list "go on processing at your taste".
I suggest to process also Ha in parallel to use it as a Luminance after the stretch and recover all the lost contrast.
This is the workflow I used for all my bicolor images.
Bob Lockwood avatar
Bob Lockwood avatar
Hello, Please keek in mind that anything you do with equiptment on hand is gerat.

As for producing an SHO image you half to use a septrate Ha, Sll, and Olll filters and a mono camera.
A color camera cannot produce an SHO image  regardless of the filters you use, it's just not possible.
Alessio Pariani avatar
Alessio Pariani avatar
Exactly Bob, this is my first statement in the previous reply
Alessio Pariani:
L-extreme allow lights from Halpha and OIII so, just to start, you cannot use properly the name SHO Hubble Palette when the S is missing;


.
Mike Brady avatar
Mike Brady avatar
Todd,
Thank you for the information and clear instruction on how to use Pixel math and color mask.  I am using a ZWO ASI2600 color cooled CMOS camera with an OPT Ultra Quad narrow band filter and I have been trying to figure out how to separate and produce a false color image.  Your technique really works.
D. Jung avatar
D. Jung avatar
Bob Lockwood:
Hello, Please keek in mind that anything you do with equiptment on hand is gerat.

As for producing an SHO image you half to use a septrate Ha, Sll, and Olll filters and a mono camera.
A color camera cannot produce an SHO image  regardless of the filters you use, it's just not possible.

Why would you say you can't do a sho image with an osc camera?
the lextreme filter only sees ha and OIII. It actually closes before hb and SII.
You could use a separate SII Filter to get all three wavelength fairly separate.
It's not very efficient, since you mostly only use a quarter of your sensor, but should work nonetheless.
James avatar
James avatar
SHO is absolutely possible with a OSC.  

I've used the L-Extreme and a separate S2 filter on an ASI533 to get decent SHO results.  As stated its not efficient but it works.  Several examples on my Astrobin page.. and I uploaded a video recently showing the process.  Its pretty much identical to processing SHO from a mono.. just a couple steps early on.

https://www.youtube.com/watch?v=_yaCYtC5_G8
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Paul Macklin avatar
Paul Macklin avatar
James:
SHO is absolutely possible with a OSC.  

I've used the L-Extreme and a separate S2 filter on an ASI533 to get decent SHO results.  As stated its not efficient but it works.  Several examples on my Astrobin page.. and I uploaded a video recently showing the process.  Its pretty much identical to processing SHO from a mono.. just a couple steps early on.

https://www.youtube.com/watch?v=_yaCYtC5_G8



Do you have any examples here on AB? I've been contemplating picking up an [SII] for my asi533mc pro to try just this.
Simon Todd avatar
Simon Todd avatar
Paul Macklin:
Do you have any examples here on AB? I've been contemplating picking up an [SII] for my asi533mc pro to try just this.


I have a few

https://www.astrobin.com/pm76ar/B/

https://www.astrobin.com/43fh4e/B/

https://www.astrobin.com/l23rpn/B/
James avatar
James avatar
Paul Macklin:
James:
SHO is absolutely possible with a OSC.  

I've used the L-Extreme and a separate S2 filter on an ASI533 to get decent SHO results.  As stated its not efficient but it works.  Several examples on my Astrobin page.. and I uploaded a video recently showing the process.  Its pretty much identical to processing SHO from a mono.. just a couple steps early on.

https://www.youtube.com/watch?v=_yaCYtC5_G8



Do you have any examples here on AB? I've been contemplating picking up an [SII] for my asi533mc pro to try just this.

Yes, I have a few of them.  Here are a couple of examples:

https://www.astrobin.com/9dthzt/B/

https://www.astrobin.com/mibdhc/
Bernd Flachsbart avatar
Bernd Flachsbart avatar
Alessio Pariani:
If you want to combine Halpha and OIII to a Hubble look-a-like bicolor palette, I suggest you to:

Hi @Alessio Pariani 

Thanks a lot for this recipe!

I followed your suggestions, including to finally use the Ha as Luminance,  and I've succesfully processed my first Hubble like palette on my M16 Eagle Nebula project :-)

What do you think:


M16 - Eagle Nebula

Next time I'll try to better deal with the star colour and artifacts around the stars.

Thanks again!
Bernd
Tayson avatar
Tayson avatar
This is not a HST colors. For me its looks like bicolor.
Bernd Flachsbart avatar
Bernd Flachsbart avatar
Tayson:
This is not a HST colors. For me its looks like bicolor.

Yes, that's why I've written "Hubble like" and not "Hubble".
As Alessio described it as "Hubble look-a-like bicolor palette"

Bernd
Alessio Pariani avatar
Alessio Pariani avatar
Bernd Flachsbart:
Alessio Pariani:
If you want to combine Halpha and OIII to a Hubble look-a-like bicolor palette, I suggest you to:

Hi @Alessio Pariani 

Thanks a lot for this recipe!

I followed your suggestions, including to finally use the Ha as Luminance,  and I've succesfully processed my first Hubble like palette on my M16 Eagle Nebula project :-)

What do you think:


M16 - Eagle Nebula

Next time I'll try to better deal with the star colour and artifacts around the stars.

Thanks again!
Bernd

Hi Bernd, glad to see that it doesn’t work only for me😉
I give you a hint for the stars problem: in OIII stars are usually bigger, that’s why all your stars have a bluish halo. You should reduce them before combining.
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Alessio Pariani avatar
Alessio Pariani avatar
Tayson:
This is not a HST colors. For me its looks like bicolor.

Of course it still is a bicolor. But a bicolor usually is intended a merge to reply broadband natural colors (HOO). 
I called it HST-like because of the yellow color which does not appear out Hubble palette photos. 

Just to say it, I would not call “Hubble palette” an image where I can’t see any red signal or where Halpha is merged with SII to change it’s hue in orange. 
SII signal is very very hard to gather and to preserve, I’ve seen only a handful of images where it is present
Bernd Flachsbart avatar
Bernd Flachsbart avatar
Alessio Pariani:
I give you a hint for the stars problem: in OIII stars are usually bigger, that’s why all your stars have a bluish halo. You should reduce them before combining.

Hi Alessio

thanks for the hint, much appreciated
As you can see my mid size stars don't have that halo because I desaturared them using a star mask.
But unfortunately patience left me to create a proper mask for all those tiny stars
I will try out your hint and take my time for the star mask !

Bernd