Does Anyone Know how to Combine OSC Broadband and Narrowband data in Photoshop (M31) - Forums

Topic starter

Sep 23, 2023 · Edited: Sep 23, 2023

Hello All,
I took approximately 3.5 hours of narrowband and 7 hours of broadband data with my Spacecat 51 of M31 this week. The data looks great but I have no idea how to add the narrowband data/stack to the broadband data/stack in Photoshop. I figured if I got the narrowband data there has to be a way to combine it but don't have a clue how that's done in Photoshop. I am using a 2600MC and I used a UV/IR cut for broadband and the Antlia ALP-T for narrowband. Scope is Spacecat 51 I am looking to use the narrowband data to enhance the Ha areas of the broadband stack. Any help would be greatly appreciated!!! Regards,
Skyhunter1

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Richard Sweeney

Sep 23, 2023

Good guide here.http://bf-astro.com/tutorial/addHa.htm Obviously you need to align the stacks first.

Rodrigo Roesch

Sep 23, 2023

Hi
i just finished doing something similar. There are different ways to do it. One way is you process both images as you do normally, then you align them and copy and paste the Ha image on top of the red channel of your color image. The image may look green after that, do you may one to correct for the color.
you can also copy the red channel and paste it on top of the Ha and blend it in a 80/20 Ha/R to create a new red channel and then copy that on top of the original red channel.
You can also do the same but in a liner image

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keith levins

Sep 23, 2023

this might help for adding HA
,
https://youtu.be/OL9qLfy2wgs?si=s4-sk3xhT5hZqImn

Zachary Eichelberger

Sep 23, 2023

@Itto Ogami Hey! I'm not sure if you use SiriL image processing program or not, but it utilizes the same Pixel math function as Pixinsight has. Heres a tutorial explaining it in depth. The technique is referred to as CONTINUUM SUBTRACTION.

https://youtu.be/gRqj1nCSk_w?si=Inu9fyRQz0uxr1Z2

SiriL is free and 10x better than Photoshop for doing essential pre processing functions such as stretching (has tools for stretching that exceed Photoshop by far), background extraction, color correction, deconvolution, and of course stacking your images (seems to have cleaner results than DeepSkyStacker). SiriL also has script functionality among several other fantastic tools.

Pixel math is incredibly powerful, I'd recommend giving SiriL a go for preprocessing your image, creating the Ha only image, then using Photoshop to add that Ha only image (I manually align it then set Ha layer as screen mode, or combine with RED channel 50/50 and add back into RED).

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Emil Andronic

Sep 23, 2023 · Edited: Sep 23, 2023

Once the stacks are all aligned, what I do is, open a new greyscale file of the same size, copy and paste the red channel from the RGB photo on to the new file, then on top of it, I put the red channel from the narrowband. Change the mode to lighten and stretch the narrowband photo while keeping the background dark. I do it until the Ha regions in the narrowband photo start to show on top of the red channel from the RGB.
Then I make a duplicate layer of the RGB photo with the blending mode set to lighten and copy the flatten result from the new file on the red channel of that duplicate layer.

Here's my latest result

https://www.astrobin.com/5m9zuw/E/

Emil

Tom Marsala

Sep 23, 2023

When I did my m31 I did my HA 9-hour stack separate from my RGB 6-hour stack. I stretched and processed each one separately. Before I stack my RGB I used my h alpha as a reference frame. I put the h alpha as a layer above my RGB. I set the layer mode on the h alpha to color Dodge add. I then put an inverted mask on that Halpha and brushed in where I wanted it to show and played with the opacity. There's a ton of ways to do it; that's the way I did it. I've never done the HA paste it into the red channel but I understand that works well as well.

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Itto Ogami

Topic starter

Sep 23, 2023 · Edited: Sep 23, 2023

Emil Andronic:
Once the stacks are all aligned, what I do is, open a new greyscale file of the same size, copy and paste the red channel from the RGB photo on to the new file, then on top of it, I put the red channel from the narrowband. Change the mode to lighten and stretch the narrowband photo while keeping the background dark. I do it until the Ha regions in the narrowband photo start to show on top of the red channel from the RGB.
Then I make a duplicate layer of the RGB photo with the blending mode set to lighten and copy the flatten result from the new file on the red channel of that duplicate layer.

Here's my latest result

https://www.astrobin.com/5m9zuw/E/

Emil

OMG that's gorgeous... That's exactly what I'm looking for here... Thanks for your help!!!

Any suggestions on how to match up the data from the NB and BB? there's some slight movement from both nights.

Regards,
Itto (Jim)

Rodrigo Roesch

Sep 23, 2023

I used the way I described above for the clouds of Andromeda
https://astrob.in/gdyl4k/C/

Itto Ogami

Topic starter

Sep 23, 2023

Rodrigo Roesch:
I used the way I described above for the clouds of Andromeda
https://astrob.in/gdyl4k/C/

Another amazing example.! I did my M31 with my Spacecat 51 because I wanted the extra focal length, but I was thaaaat close to using my 135mm.

I have to master the above technique.

As I asked Tom above, any way you can suggest to line up the data? There is a slight mismatch of position and rotation as they were taken separate nights.

Regards,
Itto (Jim)

Rodrigo Roesch

Sep 23, 2023 · Edited: Sep 23, 2023

Itto Ogami:
Rodrigo Roesch:
I used the way I described above for the clouds of Andromeda
https://astrob.in/gdyl4k/C/

Another amazing example.! I did my M31 with my Spacecat 51 because I wanted the extra focal length, but I was thaaaat close to using my 135mm.

I have to master the above technique.

As I asked Tom above, any way you can suggest to line up the data? There is a slight mismatch of position and rotation as they were taken separate nights.

Regards,
Itto (Jim)

One of best software to align data is Registar. It costs $99, but it is amazing. I have used that to combined images with different telescopes and cameras.

Ordering RegiStar (aurigaimaging.com)

average_pluto_enjoyer

Sep 23, 2023

1) If you want to simply combine narrowband data with broadband side, use Starnet++ and take the starless narrowband image, and the star mask of the broadband image and apply the broadband stars using the "screen" layer option.
2) If you want to add elements of narrowband (e.g. ha structures) into you broadband image, or visa versa, then simply play around with what you want to add and isolate if onto a black background then add that as a screen layer.

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Rodrigo Roesch

Sep 23, 2023 · Edited: Sep 23, 2023

I just posted another image using similar technique to add Ha to the RGB image. I included the Ha part. As you can see, the Ha and RGB are taken with different cameras, so I used Registar to align the Ha with the color.

https://astrob.in/w96jt0/0/

Tom Marsala

Sep 24, 2023 · Edited: Sep 24, 2023

Jim, I used my narrowband image as a reference frame for the rgb. Also, under edit in Photoshop, you can hit the free transform button and rotate, move or stretch one layer over another. Just paste in the layer you want to join over the other and set the opacity to 50% or so. Then you can line up as you need to. I used the starless version of both to blend then added the stars from the rgb only.

M31 In RGB + H-Alpha

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Jacob Heppell

Sep 24, 2023

Itto Ogami:
Hello All,
I took approximately 3.5 hours of narrowband and 7 hours of broadband data with my Spacecat 51 of M31 this week. The data looks great but I have no idea how to add the narrowband data/stack to the broadband data/stack in Photoshop. I figured if I got the narrowband data there has to be a way to combine it but don't have a clue how that's done in Photoshop. I am using a 2600MC and I used a UV/IR cut for broadband and the Antlia ALP-T for narrowband. Scope is Spacecat 51 I am looking to use the narrowband data to enhance the Ha areas of the broadband stack. Any help would be greatly appreciated!!! Regards,
Skyhunter1

Depends on what role you want the narrowband data to play in the final image. But given you've said the target is M31, the best bet is to incorporate the narrowband into the RGB channels. So you could create a new red channel that is a combination of Red and Ha. How I do this in PS is by doing a "Screen" and "Overlay" blend. In PS, put the red channel as the bottom layer then place two Ha layers above it. Set the first to blend mode "Screen", and the second to blend mode "Overlay" then adjust the opacity of the Screen and Overlay layers to suit (typically under ~30% but sometimes ~10% or less).

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Roger Redcat

Sep 24, 2023

Itto Ogami:
Hello All,
I took approximately 3.5 hours of narrowband and 7 hours of broadband data with my Spacecat 51 of M31 this week. The data looks great but I have no idea how to add the narrowband data/stack to the broadband data/stack in Photoshop. I figured if I got the narrowband data there has to be a way to combine it but don't have a clue how that's done in Photoshop. I am using a 2600MC and I used a UV/IR cut for broadband and the Antlia ALP-T for narrowband. Scope is Spacecat 51 I am looking to use the narrowband data to enhance the Ha areas of the broadband stack. Any help would be greatly appreciated!!! Regards,
Image integration , after matching resolution on "Registar". https://aurigaimaging.com/
Roger

Roger Redcat

Sep 24, 2023

Image integration , after matching resolution on "Registar". https://aurigaimaging.com/
Roger

Robert Gillette

Sep 24, 2023

Thank you, Itto, for raising this question. Great to see that Photoshop is alive and well in astro imaging.

For all pre-processing, including image cleaning , aligning and stacking, I’ve long used and highly recommend CCDStack2 from CCDWare. Not free, but very reliable.

CS, Bob

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