While trying to help figure out an issue, I had access to some BXT'd data, as well as the original stack (Thanks Steve!)
The file was linear but had been ABE'd (possibly with some settings problems), BXT'd, and PCC'd. So, I opened as white-balanced, still did a Wipe but zeroed out the aggressiveness slider, no-ROI OptiDev, Color, and Denoise.
For the original stack I ran a full ST processing, meaning Wipe and OptiDev, then the usual "carve down" sequence of Contrast but locality 25%, HDR with a few changes from default, Sharp, and SVD, followed by Color and Denoise. I tried to match the overall color balance and saturation the best I could eyeball it.
I also found a HST (infrared though) image by NASA, scaled and rotated that so I could flip between all three versions.
The data was about 3 hours of RASA 11 in Bortle 3 with a 2600MC. No binning. Images were displayed at 200% and I screenshot those and cropped to match. The NASA picture was scaled
down to 58%, and I don't know if they did their own scaling in creating that image.
Setting aside the stars (across the full image BXT seemed to mush both a triple star system and a double star together a bit, and even in the Flame crop it's not resolving hidden stars), I don't necessarily see anything being made up, though I suppose that depends how you define it. But it does seem like BXT is shrinking feature details and giving them a fine-edged "clarity" that I'm not sure is reasonably supportable.
Or, is it possible I'm doing things wrong in ST such that I'm fattening details up or leaving clarity on the table? As a comparison point, I was mostly focusing on that little arrowhead shape to the left side. I also ran a ST workflow where I only applied SVD and took it up to 20 iterations. Also tried unsharp mask in Gimp, deconvolution in Siril, and even threw Registax wavelets at it. I'd have tried PI deconvolution but it seemed like way too much work. But regardless of whatever I used, the features all stayed more or less the same size, but with varying degrees of resolving. Only BXT results in those tiny fine-grained details of the same structures.
Well, except for HST infrared, which even scaled down is just off-the-charts sharp.
ST's full processing did bring out more detail overall (without the fine edges), but admittedly the BXT file was only stretched with no other enhancements applied.
In order, Original stack 200% crop, Stack with BXT 200% crop, NASA HST image 58% downscale.
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- Steve Orig FullST Flame crop 200pct.jpg (451.46 KiB) Viewed 27174 times
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- Steve BXT etc Flame crop 200pct.jpg (456.7 KiB) Viewed 27174 times
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- Flame Comp HST rot scale.jpg (465.32 KiB) Viewed 27174 times
The three files are pretty well aligned such that they can be overlaid and blinked/viewed, such as in Gimp layers.
Thoughts?
![Think :think:](./images/smilies/eusa/think.gif)