P: Polarizer Sky Automatic Correction

[Callous Sonnallous]

This is my first feature suggestion, and it comes as a user of my partners hardware/software (I only own CS6 and share their editor as a result, as an amateur.) 

Suggestion

This suggestion pertains to the introduction of some sort of automatic correction for "non-flat" masks- or to put forward a simple use case, polarizer sky correction. This should be done with masks for the simple reason that this allows more flexibility, and could be added as an option under "Effects" as the new masks panel has beem revamped. 

Possible Method

In the case of "polarizer sky" an easier solution would be something along the lines of using automatic gain control (AGC) with 2D windows on the image mask. This would run into issues where you have e.g. a very busy sky- hence it may be necessary to allow the user to not just state they want to eliminate polarizer sky, but be able to vary the windows used for the AGC (unless they want to knock out all the dynamic range in their sky by balancing all the pixels out to zero.) With large enough windows (and polarizer sky is a fairly broad effect) this should be a non-issue. Being able to specify a colour range for the AGC calculation, but applying the AGC over the entire mask (inclusive of non-selected colours- you could do an intercept for other colours if wanted!), would be good.

An alternative solution would be training ML to identify the general "flatness" of the background of the image mask, and then apply corrections appropriately. 

Alternative solutions?

There are already plugins for Photoshop capable of doing this for astrophotos- ProDigital software has a few- but specifically doing this in Lightrooom with masks would be a fantastic addition, in my opinion, and would be something quite unique. 

[Callous Sonnallous]

I forgot to say why this would be useful, but it's fairly obvious! Batch image processing with lots of CP-taken photos, stitched panoramas with complex polarized skies- you could even have unbalanced images and want to automatically correct for a gradient- a generic AGC helps with this (and with it being a mask approach, you could vary the % of application, too!) 

[GoldingD]

I would think the best place for this would be in the Masks. Not just the AI Sky mask, as one does not always use AI for a sky mask. Nor in an existing mask such as a Grad. But it's own mask. Why in masking instead of overall (as in a lens correction), because it is corrections to the sky, not to say a blue lake, etc. And may involve several brushes perhaps combined.

Typically, when I fail to pay attention and have a CPL attached when shooting a multiple frame panoramic, Resulting in an unbalanced sky. I wind up creating a mask that applies multiple linear grads to adjust WB, etc. With a intersect with color. Hence a complex mask.

[Callous Sonnallous]

Aye that sounds grand. I would imagine being able to create your own mask first for what you want to AGC, applying an 'AGC calculation' mask, and then applying that AGC calculation to another mask you define (could be the same mask or another.)