I'm trying to work out what value luminosity image capture has when combining Ha and OIII data with RGB. Can anyone point me in a direction on this? I am creating an RGB image and then combining that with narrowband data (i.e. the RGB gives me the star colour), but not sure how to use luminance data as well.
How do people use Lum captures in HAOIIIRGB images?
Well Written Engaging
This wouldn't be my preferred way of doing things but here is one way:
Use LinearFit to scale and background equalize the OIII and Ha frames to the L frame. Then add them together (L+modified Ha+modified OIII) in one way or another. Remember to use copies of the orginal not the orginals. Now you have a L-enhanced frame. Do the same for the R frame (with Ha) and the G/B frame (with OIII). Now create the NB enhanced RGB. Do the colour balancing and the use the LRGBCombination process to produce the final enhanced LRGBHaOIII colour frame.
That is assuming there is anything worth keeping in the original L frame.
Use LinearFit to scale and background equalize the OIII and Ha frames to the L frame. Then add them together (L+modified Ha+modified OIII) in one way or another. Remember to use copies of the orginal not the orginals. Now you have a L-enhanced frame. Do the same for the R frame (with Ha) and the G/B frame (with OIII). Now create the NB enhanced RGB. Do the colour balancing and the use the LRGBCombination process to produce the final enhanced LRGBHaOIII colour frame.
That is assuming there is anything worth keeping in the original L frame.
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andrea tasselli:
That is assuming there is anything worth keeping in the original L frame.
Thank you for your reply; I could try that. I guess I'm wondering if there is any point in taking luminance frames? Do you?
Well Written
Not if your going for NB being the lion's share of the data and RGB is just to show the star field.
andrea tasselli:
Not if your going for NB being the lion's share of the data and RGB is just to show the star field.
That's what I thought ... thank you ... question answered.
My experience is if you are doing a bi-color Ha+OIII (HOO) image of emission nebula it is more likely the nebula is dominated by Ha. I will bring in a processed Ha image as a luminance layer. This usually strengthens the nebula structure. If there are destink OIII areas that are moninated by blue/blue Green, I will mask those areas and bring them out with a OIII layer.
A Ha luminance layer can also apply to a Hubble palette emission nebula image. Since the Ha data brought is as green gas to be weakened and the OIII/SII strengthened, the Ha structure can be lost. A Ha luminance will bring that back.
The RGB data is used for star color. If it is strong enough, it can be used as a color layer to make the Ha\OIII image look more natural.
When doing narrow band processing, A traditional luminance layer isn't very effective. It no longer is the channel that depicts the most resolution. With emission nebula, that will be the Ha channel.
These comments are based on using PhotoShop. Other software application will vary , but the basic concepts are the same.
Lynn K.
A Ha luminance layer can also apply to a Hubble palette emission nebula image. Since the Ha data brought is as green gas to be weakened and the OIII/SII strengthened, the Ha structure can be lost. A Ha luminance will bring that back.
The RGB data is used for star color. If it is strong enough, it can be used as a color layer to make the Ha\OIII image look more natural.
When doing narrow band processing, A traditional luminance layer isn't very effective. It no longer is the channel that depicts the most resolution. With emission nebula, that will be the Ha channel.
These comments are based on using PhotoShop. Other software application will vary , but the basic concepts are the same.
Lynn K.
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