Ok, I had a go at it. Lovely data! You really got your acquisition down pat - something a lot of people still struggle with, even years later!
The data clearly has not been pre-color balanced, which allows StarTools to make the most of it - great!
Now bear in mind that a lot is also a matter of taste.
Here goes;
--- Auto Develop
Default parameters.
To see what we got. StarTools shows the most pressing issues, being the stacking artifacts and the blue bias. Data looks pretty good. At this stage it's still a bit hard to tell if the data is oversampled or not (e.g. whether binning would be a better option).
--- Crop
First I crop away the artifacts.
Parameter [X1] set to [26 pixels]
Parameter [Y1] set to [113 pixels]
Parameter [X2] set to [4174 pixels (-116)]
Parameter [Y2] set to [2701 pixels (-155)]
--- Wipe
I use Wipe with default parameters to get rid of the bias. As we're still at full resolution, I'm bumping up [Dark Anomaly Filter] to [3 pixels]; this will catch any dead/dark pixels if they're present, so that it doesn't interfere with Wipe's attempt to find the local background.
You can use the Temporary AutoDev feature to see the result. Pretty good I'd say! If you're worried about removing faint nebulosity, you can mask out the bubble if needed (I didn't bother with that).
--- Auto Develop
I launch AutoDev again for the final stretch.
I can now see that at 100% resolution the image is a bit blurry; a combination of atmospheric (seeing) and (possibly) optical limitations. This is very common (in fact it's more often than not the case with DSLR data). If 'smaller'/fainter stars aren't pin points that have their light mostly concentrated in a 3x3 area, then your image is probably oversampled.
The nice thing about oversampled data is that we can use the multiple-samples-per-real-unit-of-resolved-detail to create a better estimate for the real detail (e.g. improve the Signal-to-Noise Ratio without losing real detail), using binning. All this will result in a smaller image (without loss of real detail) that has less noise and, hence, can be pushed harder (for example by stretching more, or by using deconvolution).
--- Bin
I settled for binning to 25% of the original resolution, coalescing roughly every 2x2 pixel block into a new pixel reading that is 4x as accurate.
Parameter [Scale] set to [(scale/noise reduction 50.00%)/(400.00%)/(+2.00 bits)]
--- Auto Develop
I now return to AutoDev again for my final stretch.
I click & drag a Region of Interest over the bubble and surrounding area, as I feel it's the main subject of this image. This will create a global stretch that is optimised for showing exactly that area,
I allow the rest of the image to influence the stretch about 5% (Parameter [Outside ROI Influence] set to [5 %])
--- Deconvolution
I let decon create a mask automatically.
With parameter [Radius] set to [2.3 pixels], we're able to dig out a small bit of extra detail in the bubble. We'll take what we can get!
--- Wavelet Sharpen
Using the same mask decon created, I apply some wavelet sharpening to bring out the structures in the bubble a bit more. It's totally to taste.
Parameter [Amount] set to [250 %]
--- Color
This is (IMHO) an important one that gets overlooked a lot; final colour calibration. It is preferably performed towards the end of the work flow.
The colours ST comes up with by default are very close to ideal. Things to look out for is a nice even distribution of all star temperatures across the field (from red->ornage->yellow->white->blue).
Using the MaxRGB button we can see a slight over-representation of green (green should rarely be dominant), so I dial it back a little.
I also introduce more color in the fainter parts, as your data can take it; color noise is fairly low.
Finally, I dial back the saturation to 100%.
Parameter [Dark Saturation] set to [9.80]
Parameter [Saturation Amount] set to [100 %]
Parameter [Green Bias Reduce] set to [1.49]
Parameter [Red Bias Reduce] set to [1.35]
--- Life
The star field is quite busy and can obscure fainter large scale structures in the background.
The Life module's Isolate preset can help in such cases.
--- Wavelet De-Noise
(switching Tracking off)
Final noise reduction to taste.
That's it! And this is what I ended up with;
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- bubble.jpg (1002.52 KiB) Viewed 5533 times
Hope this helps...
