Combining LRGB image with Ha,OIII, or SII

[yusbot]

Hi guys,

I saw some pictures from the pros have a combination of narrowband image to its LRGB image. I wonder how they put the narrowband channel together with RGB? Since there only 3 channels of RGB?

I know sometimes I notice that they put Ha layer as Luminance, but I think this one is totally different. Are they stacking the narrowband frame with one of RGB channel before processing in Photoshop/PI? If so, into what channel is preferable? Is there any special move to stack them?

I talk about nebula pictures that have blueish tint on it...

Regards,
Yusfi

[rustigsmed]

hi Yusfi,

yep there is no hard and fast move to do it.

most people blend in NB with one of the channels at a time. more often than not it will be Ha and o3. they could also create a synthetic luminance and layer it in that way also, or do both.



cheers

russ

[yusbot]

Thanks russ, I just learned from your flickr collection.
Beautiful pictures!

Regards,
Yusfi

[rustigsmed]

Thanks Yusfi,

check these links out it may help further

http://bf-astro.com/hubblep.htm

also this one from starizona
https://starizona.com/acb/ccd/software/ps_hargb.aspx (https://starizona.com/acb/ccd/software/ps_hargb.aspx)
i can't seem to open the link at the moment but from memory it had some techniques of adding Ha to the Red channel.

Cheers

Russ

[Somnium]

not that i have done it but don't some people create a star mask and replace the NB stars with RGB ones? it is usually the stars that look strange in NB images.

[glend]

I am wondering about combining OSC images and Narrowband. I have two identical Canon DSLRs (cooled) one mono and one colour, identical sensor pixel size etc. The colour camera is full spectrum, so picks up much more Ha than a stock filtered camera, but is limited by the Bayer Matrix as to how much Ha it can gather. The mono camera however, can be pure Ha with a Ha filter. If I make a OSC stack, and a Mono Ha stack, and register them together like I would for a pure narrow band composite, is there any reason they cannot be layered together in PS?
Hmm, maybe luminance as well.

[barx1963]

I found a very good video on processing LRGB images last night. Will post the link when I am back at home in an hour or so.

Cheers

Malcolm

[rustigsmed]

No reason why not at all :thumbsup:

Below is a sequence of ngc 6164

done on a canon

straight RGB
Ha RGB
Ha Oiii RGB

the antennae galaxy was a mix of old RGB data from my canon 600d and a few subs of luminance from my QHY22.

I use RegiStar which figures out image scales and orientations. makes life way easier. as you know we are talking about different sized images. but i also need to use PS.

edit: found the original canon antennae with no luminance from the qhy22.

russ

[barx1963]

Finally found the video!!

https://www.youtube.com/watch?v=b9ePip4rdsI

Malcolm

[yusbot]

Hi Russ, on your Ha OIII RGB image, did you stack the Ha and OIII together? and make them as Luminance layer in Photoshop? or how?

[rustigsmed]

Hi Yusfi,

They were done separately.
From memory I merged the Ha with the Red channel, and the Oiii with the blue channel. So really its Red+Ha, Green, Blue+Oiii. :thumbsup: hope that helps.

Russ