Dealing with heavy light pollution gradients

[Desther]

I am new to StarTools and have a mosaic milky way image with a heavy light pollution gradient, clouds and some patchy areas that are revealed when stretching. Can anyone give advice on how to deal with this? For Wipe, should the core be covered in green mask or excluded from green?

50mm f/2, 30s, ISO 1600, 25 single exposures with flats applied in DSS

Here's the tiff and my attempt:

https://www.dropbox.com/s/xlg7ewllegh1i ... s.tif?dl=0

https://i.imgur.com/3cXG2y2.png

Code: Select all

--- 
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [2.8 pixels]
Parameter [Outside ROI Influence] set to [64 %]
--- Wipe
Parameter [Mode] set to [Correct Color & Brightness]
Parameter [UNKNOWN] set to [No]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [1 pixels]
Parameter [Drop Off Point] set to [100 %]
Parameter [Corner Aggressiveness] set to [100 %]
Parameter [Aggressiveness] set to [75 %]
Undo.
--- Wipe
Parameter [Mode] set to [Correct Color & Brightness]
Parameter [UNKNOWN] set to [Yes]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [1 pixels]
Parameter [Drop Off Point] set to [100 %]
Parameter [Corner Aggressiveness] set to [100 %]
Parameter [Aggressiveness] set to [75 %]
--- Auto Develop
Parameter [Ignore Fine Detail <] set to [1.2 pixels]
Parameter [Outside ROI Influence] set to [2 %]
--- Wipe
Parameter [Mode] set to [Correct Color & Brightness]
Parameter [UNKNOWN] set to [Yes]
Parameter [Precision] set to [256 x 256 pixels]
Parameter [Dark Anomaly Filter] set to [1 pixels]
Parameter [Drop Off Point] set to [100 %]
Parameter [Corner Aggressiveness] set to [100 %]
Parameter [Aggressiveness] set to [75 %]
--- Develop
Parameter [White Calibration] set to [Use Stars]
Parameter [Gamma] set to [1.00]
Parameter [Skyglow] set to [0 %]
Parameter [Digital Development] set to [84.28 %]
Parameter [Blue Luminance Contrib.] set to [100 %]
Parameter [Green Luminance Contrib.] set to [100 %]
Parameter [Red Luminance Contrib.] set to [100 %]
Parameter [Dark Anomaly Headroom] set to [5 %]
Parameter [Dark Anomaly Filter] set to [2.1 pixels]
--- Life
Parameter [Detail Preservation] set to [Linear Brightness Mask]
Parameter [Compositing Algorithm] set to [Multiply, Gamma Correct]
Parameter [Inherit Brightness, Color] set to [Off]
Parameter [Output Glow Only] set to [No]
Parameter [Airy Disk Sampling] set to [128 x 128 pixels]
Parameter [Airy Disk Radius] set to [8 pixels]
Parameter [Glow Threshold] set to [0 %]
Parameter [Detail Preservation Radius] set to [20.0 pixels]
Parameter [Saturation] set to [100 %]
Parameter [Strength] set to [100 %]
Parameter [Mask Fuzz] set to [1.0 pixels]

Thanks!

[admin]

Hi,

With data like this it's very hard for a computer algorithm (as well as a human) to distinguish between "gradient" and detail/signal. A light pollution dome (or cloud cover/haze) in a particular location in a widefield like thsi is no longer a gradient but a localised light source.

Gradient removal is possible when the gradient undulates slowly (or preferably, doesn't undulate at all and just falls off).

Relative uniformity of the gradient is key in being able to model it, but unfortunately that is not the case here...

[Desther]

Ok, thanks for the reply