Compose Module Bicolor exposure

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Melty
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Joined: Fri Dec 22, 2017 1:18 pm

Compose Module Bicolor exposure

Post by Melty »

I was just wondering, what's the best value to set the exposure sliders to for Bicolor in this module when using mono Ha and Oiii filters?

I know to set Luminance/Color value to "L + Synthetic L from RGB, R(GB)(GB) (BiColor)"

For example I might have:

50000s with my Ha filter
50000s with my Oiii filter

Do i:

1) Import Ha into the Red/SII selector and set the red exposure slider to 43200s (what it maxes out to).
2) Import Oiii into the Green/Ha and Blue/Oiii selectors and set the Green and Blue exposure sliders to 43200s or 21600s each? I'm not sure which value it should be.

Cheers

Oops, sorry - I've just remembered I posted this previously, but it went unanswered.
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admin
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Re: Compose Module Bicolor exposure

Post by admin »

Hi,

The question was indeed answered (but a bit late after I missed it! :oops:)
Hi,

Apologies for the delay in getting back to you.

You would load 15840s of O-III in either blue or green, but not both.
You want your O-III to be counted only once when it is added to the Ha signal for synthetic luminance purposes.
Meanwhile, for color purposed, green = G+B, and blue = G+B as well, so the O-III will be used in both the blue and green channels equally for coloring purposes. With Ha in the red channel, this yields the default red/cyan bi-coloring.

I seem to get rather disappointingly washed out colour with whichever way I choose to process and can't figure out why. Colour seemed better saturated with my OSC and l-enhance using open instead of the compose module.

That sounds very strange - there should be very little difference and even if there was, the myriad of options in the Color module should allow for any type of saturation selection you see fit.

Would you be able to share the dataset with me?
Hope this helps!
Ivo Jager
StarTools creator and astronomy enthusiast
Melty
Posts: 21
Joined: Fri Dec 22, 2017 1:18 pm

Re: Compose Module Bicolor exposure

Post by Melty »

Hi Ivo,

Sorry, I completely missed the fact that you'd replied to my earlier message!

I'd never considered using just the green or blue channel alone, so thanks for that. :thumbsup:

With additional data, it seems that I'm on top of my earlier low colour problem. I may also may have made subtle changes to my workflow, but I don't recall and am I'm not 100% sure.

My data is still available if you want it, but the FITS files are on the huge side (47mp each channel).

Thanks!
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admin
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Re: Compose Module Bicolor exposure

Post by admin »

Melty wrote: Wed Jun 02, 2021 11:54 am With additional data, it seems that I'm on top of my earlier low colour problem. I may also may have made subtle changes to my workflow, but I don't recall and am I'm not 100% sure.
Sometimes accidentally skipping Wipe (don't!) can cause colors to come out barely or not at all. Would that perhaps have been the issue?
My data is still available if you want it, but the FITS files are on the huge side (47mp each channel).
Of course, please feel free to share it if you have any remaining issues.
Ivo Jager
StarTools creator and astronomy enthusiast
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