Narrowband balancing, throttling, boosting

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Mike in Rancho
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Re: Narrowband balancing, throttling, boosting

Post by Mike in Rancho »

admin wrote: Mon Mar 06, 2023 12:26 am Hope this helps!
More than I expected - not having anticipated having my assumptions and dreams crushed about the initial intensity state of narrowband channel blending. :(

I will clearly have to keep this epiphany in mind now, both processing my own NB data, and viewing that of others.

admin wrote: Mon Mar 06, 2023 12:26 am The entire point of the excercise is to explain that the Color module is categorically not for recovering detail. If you are trying to recover detail with the Color module, you are probably using the worst possible tool in StarTools to do that. In fact, it actively tries to suppress any detail enhancement as much as it can (it will never 100% succeeed in all cases due to gamut issues requiring compromises; for example making blue look visually as bright as the brightest green, the other channels have to pitch in a lot).
Possible clarification - I mentioned Color module there simply because it was necessary otherwise ST would save out a "grayscale" tiff. That saved RGB file (my analog to initial weaker OIII in the jeans and jacket) I then started over with from scratch, and yes was trying various stretching and enhancing modules to see if detail could be yanked back out. Color then came again later.

admin wrote: Mon Mar 06, 2023 12:26 am As long as you understand the difference between contrasting hues ("red vs blue vs green") and contrasting detail ("bright vs dark").
Well. Gee. Do I? Ruh roh. :confusion-shrug:

That was somewhat of a basis for all of this, contemplating both the weak-band boost and bolder coloration (a la Martin's thread), as to my eyes that color is almost necessary to assist in seeing that contrasting detail, especially where the emissions bands change.

This isn't a perfect example as the OIII shown started out moderately strong, but here's a little corner of my Flaming Star, specifically the ducky pond with little tadpoles. No SS or denoise or anything yet, so it's a little ragged. Well, it was low integration and ragged anyway, but no matter. ;) Also some rings here in 546. Still a fan of 536 for SVD/deringing, though I've found I can fix up 90% of this with a no iterations Shrink deringing. But I digress yet again...

The luminance is okay, but I'm hard pressed to notice a lot of the features that are all lost there in a sea of gray. With color and SHO mapping and balancing, suddenly - to me - a whole lot more interesting detail and information is available. And the more those colors can boldly contrast, the more I am then able to pick up on it. Plus the tadpoles just look a lot cooler, but the concept goes for all the other fainter interspersed colors too.

Corner pond Lum-Color SHO.jpg
Corner pond Lum-Color SHO.jpg (390.14 KiB) Viewed 9732 times

Edited: typos :oops:
Last edited by Mike in Rancho on Tue Mar 07, 2023 7:35 am, edited 1 time in total.
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Re: Narrowband balancing, throttling, boosting

Post by admin »

Great example!
Mike in Rancho wrote: Mon Mar 06, 2023 7:00 am With color and SHO mapping and balancing, suddenly - to me - a whole more interesting detail and information is available. And the more those colors can boldly contrast, the more I am then able to pick up on it. Plus the tadpoles just look a lot cooler, but the concept goes for all the other fainter interspersed colors too.
Absolutely - contrasting hues are super important (and which hues that's whole other topic) to help discern detail between the bands; color adds a whole extra dimension. And the great thing is that if you keep luminance and color separate, you have a whole lot more leeway boosting/balancing those - to achieve maximum color contrast - without running into noise issues. :thumbsup:
Ivo Jager
StarTools creator and astronomy enthusiast
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