Synthetic Luminance

Zak’s Astrophotography

Hi Adam,

First off, just want to say I’m absolutely loving your tutorials! It’s really easy to understand what you are saying and the way you are presenting how you are doing it really helps with my autism and auditory processing as I am a heavy visual learner. Keep up the good work, and I cannot wait to see what other tricks up your sleeve you may have in store for us!

The reason I am posting this thread is to ask about synthetic luminance channels in PixInsight. Would it be worth creating them for my DSLR data, and how would I go about incorporating it into my images?

I can’t remember if you have a tutorial about this in your videos sorry but if you don’t would you consider creating a tutorial based on synthetic luminance channels, specifically DSLR/OSC data? I understand if you can’t.

I’m not too sure where to put this thread sorry Adam, but I thought it would be best to post it here in the PixInsight side of the forums.

Hope all is well your end of the world!

Zak

BlockHead

Hi Zak,

This is the right place for your question. Thanks.

There are a couple of reasons to create a synthetic luminance:

1. There may be artifacts in some of the data- or some other reason that you might combine all of the RGB together in order to get a better signal/noise result. 

2. You want to create a luminance from an RGB image in order to sharpen and adjust the contrast of this luminance independently of the color channels and then combine them for an improved result. 

Fewer and fewer people are doing LRGB (at least as I used to do it) today... so I do not have a specific tutorial on it. I do have workflow examples with LRGB data from mono sensors... but not for a color filter array. Typically with OSC... there isn't that much benefit since the images are not usually of the same S/N to make a separate luminance image useful. In cases where it does help... the data sets are exceptional.

-the Blockhead

Zak’s Astrophotography

Hi Adam,

Apologies in the huge delay in the response, have been super busy with studies plus there was COVID in the household not too long ago.

Thanks for your insights about synthetic luminance, I did do some testing with it and like you said I found very little benefit in doing it, in fact I think it made my images look worse than what they were before the synthetic luminance.

I don't think going forward that I will use synthetic luminance images, unless I actually have a mono camera with LRGB filters, then I will use the luminance data and process it separately. It's not on my list at the moment, but I will definitely be upgrading in the future when the time is right.

Zak :)