How to remove light pollution down the image and unit sky color ?

[Hamad]

Hi guys 

During post processing of this photo of the Milky Way I had a problem on how to reduce the light pollution in down the photo..  cause once I started to adjust the shadows and contrast it becomes very clear .. I want to unite the sky color  

 

I did read a lot about how to use curves, shadows, white balance and many other things .. 

 

but don’t know how to fix this issue, I’m using iPad btw 

 

I’ll include the image  

Thanks 

DSC00498.ARW

[NotMyFault]

I would suggest to watch the excellent tutorial videos from James Ritson. He made a live stream last week showing how to edit astrophotography, including removing background color.

https://affinity.help/photo/English.lproj/pages/Filters/filter_removeBackground.html

 

[Hamad]

Thanks for your answer 

I did  some search before and all I can find is videos an tutorials about reduce light pill room in the entire image .. and using laptops which kind make me can’t follow with them or do what they do .. 

 

I’ll read the link you sent later today  and see if It’s helpful .. thanks again  

[NotMyFault]

Sorry i missed you are using iPad. Unfortunately the Astro Background filter is unavailable here.

Another simple method:

• add a fill layer on top
• Deactivate fill layer
• set blend mode to subtract
• use color sample tool
• set size to taste, e.g. 17x17
• click into an area having and average background color
•  Activate fill layer
• set blend range “destination” to include only darker areas (see screenshot)
• maybe adjust fill layer opacity

To get a more local result, instead of fill layer use a copy of original bitmap.

blur with large radius, and set blend mode to divide Or subtract. Use blend range on source to exclude stars and other brighter areas.

another brute force option is to use levels or curves or shadow / brightness to darken the background tones.

[Hamad]

Thanks for your efforts 

I tried the first method ending with “ adjust fill capacity “ but didn’t work .. once I start Brighten the image I see the yellowish color  

If you don’t mind can you download the photo I uploaded and work around with it while screen recored so I can follow up with you better ? 

 

[NotMyFault]

The methods are explained here:

You may need to adjust the methods as Astro images differ in exposure.

The second method, but using blend mode saturation, is what i described before.

 

[Hamad]

Thank you