Effect of Multiple Mask Order (not submasks)

[Petrula]

Lightroom Classic 13.0.1  Camera Raw 16.0
Windows 10 Pro, Version 22H2, OS build 19045.3448

Could you please discuss the order of multiple masks (not submasks, but multiple masks).

Changing the mask order has effects.

I am unclear how the order effects what is visible and what is hidden.

Thank you for the feedback.

[richardplondon]

The first photo below shows 2 different local adjustment masks on the same image,

the left circle applies Saturation 0 and the right circle applies Saturation 100. 

So the overlap of those two results in a net zero override (same as saturation 50) to the starting saturation of the imported Raw. The non-overlapping areas show in an uninterfered way, the full override that each mask is imposing.

Here's another test with the adjustments applied by the same two masks reversed (and I also renamed them for clarity) 

Looks as if they are overlapping the same way, giving a net zero override of saturation when combined.

In other words if you apply in effect first + 50 saturation and then -50 saturation, that is the same outcome as applying first -50 and then +50, also the same as doing nothing at all, provided that these saturation adjustments are working non-destructively in their sequence.

Now let's look at how these two will respond to a Basic panel global adjustment of +100 saturation.

First, the version with desaturated area on the left imposed by the lowermost adjustment in the Masks panel.

And just for completeness, with desaturated area on the right imposed by the uppermost adjustment in the Masks panel.

Same result so far as each mask, same result so far as the overlap, both responding the same to global adjustment..

AFAICT from this, the relative ordering within the Masks panel does not seem to matter (mask subcomponents are a different matter). If one mask's desaturation HAD quasi-destructively denied the other mask anything to then increase the saturation of, these tests would have varied in the overlap area.

It also I hope satisfactorily shows the dependent sequence of first local, then global adjustment. Incidentally global Tone Curve then follows after global. If a given area of the photo shows blown highlights under given constant global settings, then a local adjustment (darkening) can in effect retrieve those so they are not blown, providing that this highlight detail is present within the camera file of course. But Tone Curve cannot be used to reverse this blowing-out of the highlight detail. It can only work from what it is given.

[Petrula]

richardplondon - I very much appreciate your detailed feedback.

Your pictures clearly show that "the relative ordering within the Masks panel does not seem to matter (mask subcomponents are a different matter)".

It was difficult to tell the effect of adding the Basic panel global adjustment of +100 saturation. For that picture, the area outside the circles looks the same as when there was no Basic panel global adjustment. I would have expected to see the effect of the Basic adjustment outside the circles.

You mention that

"It also I hope satisfactorily shows the dependent sequence of first local, then global adjustment. Incidentally global Tone Curve then follows after global. If a given area of the photo shows blown highlights under given constant global settings, then a local adjustment (darkening) can in effect retrieve those so they are not blown, providing that this highlight detail is present within the camera file of course. But Tone Curve cannot be used to reverse this blowing-out of the highlight detail. It can only work from what it is given."

"the dependent sequence of first local, then global adjustment" implies one should first do local and then global adjustments.

The Adobe help

https://helpx.adobe.com/lightroom-classic/kb/optimize-performance-lightroom.html

has in the topic"Order of Develop operations", the following sequence

1) Denoise

2) Content-Aware Remove/Heal/Spot

3) Lens Profile Corrections (CA and Profile, if available)

3) Profile

4) Global Adjustments

5) Local Adjustments

So which should come first local or global adjustments?

I appreciate your feedback.

[richardplondon]

I am seeing a definite difference of saturation from the global (Basic panel) +100 saturation, for the image area sitting outside of both circles. Look for example at the windows, which have become full yellow..

So far as order of operations, Adobe recommends a working sequence to minimise wasted user effort, which arises from some ramifications of how the software works. My comments were about the underlying facts of how the software works (dependency of one thing on another). Those facts inform the working advice - which I do agree with.

Example 1: if you do a Select Sky local mask operation, and then you do some spot healing, the Select Sky may now need to be re-generated to take account of this healing. Completing healing first, and only then generating a Select Sky, means this AI calculation can happen once, instead of twice, overall. 

Example 2: if you make local adjustments based on the appearance of the image under default global settings (not the ones you will finally want), and only then do you alter those global settings - you may find that those previously made local adjustments now seem inappropriately judged, and need further update. Working the other way around gets more straightforwardly to your preferred end result. So local applies before global in the software's internal processing chain; yet it makes practical sense for the user, where possible, to generally work on global adjustments before local.

[John R Ellis]

"Changing the mask order has effects."

Please give an example with screenshots, so we're all talking about the same thing. Adobe unfortunately uses the term "mask" ambiguously.