How to add the luminance channel in an image


As I went through all the old observations I noticed we had a good set of R, G, and B for NGC 1300, but no L. We have other sets like that in there too.

As you know the luminance channel is one that brings out some of that extra detail in many images, though sometimes it isn't always needed such as when doing really bright globular clusters with a bright core. Still, there are times when the luminance channel will make a big difference in what your final image looks like.

An excellent way to get that luminance is to go for an Advanced Request on it. I did it on the NGC 1300 set just to see what I could get out of it, and it made a nice difference. Only going for one channel also cuts that cost substantially due to needing less of it and due to cutting the overheads.

Since there was a total of 12x R, G, and B and 300s each I figured 12x 300s on L would work nicely. I scheduled it on the same scope that did the original, CHI-1 and waited for it to come on in. After it completed I ran a stack on both and did the same processing on each. I will let you be the judge on the final image results.

I think you will see why I think it is a good idea to get that luminance on a nice and cheap advanced request and add it into some of the data that doesn't have it already. Image 1 is with the L channel and image 2 is without. Both were stacked in APP and automatically stretched at the 20% level, then dropped into Photoshop for a little NR and making the background more even, then a boost in vibrance and saturation. Here they are!

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Image 1 and Image 2

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