RT Dev, DeltaE behavior with multiple tools

Can someone help me here. I am trying to decide if I should report an issue or not on the behavior the deltaE function in Local Adjustments when multiple tools are selected. It seems that it should not be available when two tools are operating on different scopes, as the output is not meaningful. Am I missing something?

Using the raw from Blacks out-of-gamut
DeltaE.pp3 (18.9 KB)
Here it is when just Dehaze (with a reduced scope) is turned on

And here it is when just Color is turned on

But when both are turned on things stop making sense. It appears to be an inverse of Dehaze only?

I just had a look at this and when both tools are turned on and preview deltaE is active the mask shown looks off, but I’m not sure what to expect when doing this.

The tools are doing the correct thing based on their individual masks, though!

I’m not sure if this is as designed or an actual bug to be honest.

In my workflow, if I apply multiple tools to the same spot, and these tools have individual Scope sliders I always turn off the other tool(s) to dial in that specific Scope.

Each scope has its own target and turning them all on when dialling in using Preview deltaE just sounds wrong to me. I really would not know what to expect when multiple masks are shown at the same time. Maybe give each scope (group) its own colour?

The again, I’m not one of the RawTherapee developers…

This is what I do as well. I fear the ultimate solution would be to redo the GUI so that deltaE can only be turned on for one tool at a time… but we are likely way too late in the game for that :pensive:

As @Jade_NL says, showing a mask with multiple tools active leads to undefined behavior.

This solution sounds most plausible to me. And never say never, this is a valid request! Probably not for 5.9, but maybe for later.

If you are referring to the general button “preview AE”: Only works with one module

Wouldn’t it make sense to place a “Preview AE” button in every tool menu then instead of a global one and make it only possible to have one activated at a time?

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There is:

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Yes but why is there also the other one? I feel like it just complicates the UI.

The general that is the easy is in the basic mode. The others are for the standard or advanced mode.

hello all,

Just as a reminder. Originally the design, deltaE (as well as other settings) was only accessible through “Mask and mofications”.

I was asked over a year or more ago to add a common “Preview deltaE” button. I warned that this would result in what is described…

I was also asked to put only one “scope” for the “Color” tools… Which I think is not optimal…

You can’t have your cake and eat it too.

When it comes to managing the delatE simultaneously on several Spots, it’s a bit of an obstacle course, and is almost insoluble, if not a very complex code.

But I remain at disposal to improve when it is possible.



Jacques, thank you for all of your tireless work. There is a saying we have in English that a camel is a horse designed by committee. You are never going to please everyone.


And this is why I recommend that you only add ONE tool to an LA spot.
Multiple spots are more controllable too, and take no longer to set up than one spot with multiple tools.


Particularly easy with the Duplicate function.

Question: Would changing it to one tool per spot break backwards compatibility with current multi-spot pp3’s?

I think it should be possible to keep the functionality “under the hood” and just restrict it by taking away the option to add a second tool in the UI. This way you’d be able to open older pp3s with multiple tools on one spot.

I for one support Andy’s suggestion. A duplicated spot should appear at exact the same coordinates though. Not sure if it does right now.

I would still lose the ability to tweak them. Although it was a known risk for using a nightly, so too bad on me.

It currently does not. The problem with it appearing in the exact same spot is that on the image itself, there would no indication on the image that you duplicated it.

Also, the more I think about it, were we to go down this road, the ‘duplicate’ function is not really what we want because it copies the tool as well. So what we would really need is two different duplicate functions. One that behaves like the current one, and copies the spot with the tool and offsets it. A second one would copy the spot sans tool and be located in the exact same coordinates. I am still thinking about what to call the new function, maybe ‘Add tool’. so the buttons would be:
[Add] [Delete] [Duplicate Spot] [Add Tool] [Show/hide]

I was thinking it would load the file with all tools exactly like in former versions, you’d just not be able to add more than one tool in new files.

How about ‘duplicate’ only duplicates the spot and you’d have a copy/paste function in every tool menu.

Being the designer of the system - with Pierre @Pandagrapher for the GUI, and the participation of the whole team including Ingo @heckflosse to optimize the code and improve functionnalities - , there is no “one” right solution. But the best one is the one you master.

Both systems work with their advantages (and disadvantages)…

The advantage of creating a second Spot…is that there is another one and in particular to be able to play on the differences of positonnement and thus of the references (hue, chroma, luma).

Some duplications are obviously necessary like “excluding spots” (which also allows you to do the “inverse” functions) or “merge file” in “Color and Light” with “Multiply, Soft Light, Overlay, etc.”

If you use the most complex functions, like for example “denoise”, “wavelet”, “retinex” you will probably want to use a spot - a tool.

Another tool can (almost) work alone in most cases, it is “Log encoding” associated with Ciecam

Working with a spot and several tools has the advantage of using the notion of object…and makes it easier to read the image…and modify.

So in summary the system allows what you want, it has its limits, for example the masks do not all have the same functionality, graduated filter are different, the GUI is already complex, but works well, and can certainly be improved, etc.

Of course we can still make improvements, but it seems to me that it is necessary to take a break in the development of new features



I don’t think there is any need to restrict a local adjustment to just one tool. I think it is better to allow people to use multiple tools if they wish, but strongly recommend in both the documentation and the tool tips that they use one tool per LA spot.

I really have to agree with Jacques @jdc in that we don’t need new features at the moment in this specific tool, especially not those that restrict the current flexibility in any way. If I have to choose between flexible and a bit less user-friendly or loss of flexibility and ease of use I will definitely choose flexibility.

And as pointed out by others the answer to the initial problem is mentioned in a pop-up and in the docs. I really do not see the need to restrict a (new) spot to just one tool. Andy’s @Andy_Astbury1’s comment seems to be the solution if you want to keep it simpler. Then again, many individual spots introduces a different kind of complicated…

Just a simple request from my side: Please don’t “dumb down” this very powerful tool just because it isn’t all that easy to initially figure out how it all works.

I get Jaque’s point and if there’s use cases that benefit from multiple tools in one spot I agree that it should be kept that way.

Maybe ‘complicated’ is the wrong word. Right now it just doesn’t seem quite ‘clean’ with the behavior of the deltaE preview. Maybe that’s a better word.

Anyway, we were just spitballing here. I am absolutely happy with and thankful for the work the developers have done.