Lightroom Classic: Curves inside Enhanced Profiles being processed AFTER curves in main settings

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Hi! I'm trying to use a combination of settings inside Enhanced Profiles and settings inside the main Lightroom panels for my presets and plugins, and I'm running into a bit of an issue... 

It seems that R/G/B curves inside of an Enhanced Profile are being processed AFTER the R/G/B curves in the main settings (rather than before, like you would expect a profile to do). This is causing some unexpected results... 

For example, if I have R/G/B curves in the enhanced profile, and then I go to edit the R/G/B curves in the regular Lightroom panel, I would expect the changes that I make in the Lightroom panel to be additive to what was built in to the profile (i.e. processed later in the chain). But instead, I am seeing some odd results because the changes I'm making in the Lightroom panel are happening earlier in the chain, and then being processed through the Enhanced Profile. 

Also as an example... I have this color negative that i want to process using two distinct sets of R/G/B curves...



First I use step #1 of R/G/B curves to normalize each color channel....



Then, I use step #2 of R/G/B curves to invert, color correct, and add contrast...



^ Above is how it should look if ordered properly (and how it looks if I place step #1 of R/G/B settings in the main Lightroom settings, and step #2 in the Enhanced Profile settings...

If I place step #1 in the enhanced profiles, and step #2 in the main Lightroom settings (as I believe it should be processed), you end up with this instead:



Yuck!

If there is any way for Adobe to revise and have the curves in the enhanced profiles processed BEFORE the main settings, it would make the enhanced profiles much more usable for presets settings and other purposes!

Thank you!



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Nathan Johnson

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Posted 2 months ago

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Anthony Blackett

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If the profile were applied very early in the chain, then I suspect we wouldn't have the problems that we do in trying to process RAW images of film negatives. It would be great if profiles could be applied in such a way that ALL the Lr controls worked on the result of the profile rather than on the negative.

An option in the profile to place it early in the processing chain would be good.

However, after all the requests to do something to help process RAW images of film negatives in Lr have been completely ignored by Adobe and the development team for years, I wouldn't hold my breath waiting for anything to be done.
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Todd Shaner, Champion

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I think the primary issue is that an option to invert the image data between steps #1 and #2 as shown below is needed:

The processing pipe
So, this is how, in vastly simplified form, you process your raw data in context of a DNG Camera Profile, assuming the Forward and Reduction Matrixes are not present (see the specification for more detail):

    
    1.Linearize, rescale, do black level compensation, clip, etc.
    2.Derive interpolated ColorMatrix and HueSatDelta matrixes based on the color temperature.
    3.Get to an XYZ (absolute color space) via the interpolated ColorMatrix.
    4.Convert to HSV.
    5.Apply the interpolated HueSatDelta mapping table to get new colors.
    6.Convert back to XYZ.
    7.Do your exposure compensation, fill light, etc in whatever color space you want
    8.Convert to HSV, apply the LookTable and ToneCurve, convert back. Or, if I read the spec right, use the LookTable and the ToneCurve as the basis for your adjustment settings
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Anthony Blackett

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Yes, an invert in the approriate position, as you say Todd, between 1 and 2 in these steps of the processing pipeline is what is needed, but it is being resisted for some unknown and unexplained reason.
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Nathan Johnson

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Anthony: Agreed... but the implication here goes well beyond the negative example I gave and really effects EVERYONE... for instance, the default camera profile is now "Adobe Color" - which is an "enhanced profile" that at its core is just a reference to the Adobe Standard dcp file, plus a tone curve thrown on top (different than the tone curve in the dcp file itself) and another looktable. I've seen some unexpected tonal behaviors when working off of Adobe Color, and now it makes sense why... because the tone curve from Adobe Color is being applied AFTER the tone curve in the main Lightroom controls. I saw the same thing with the X-Chrome presets I make – when using enhanced profiles to set the base tonal changes, things were always just a touch off in my measurements, and I could never understand why exactly until now. 

Todd: For me,  it's not just about having an option to invert image data... that's just an example... it seems to me in general that the expectation of the new enhanced profiles is that they happen earlier in the pipeline than the other visible settings... since they don't, it means that they could react in unintended ways to user input (or special use cases where order is vital). I could be wrong, but I'm not sure if Adobe has anywhere specifically told us the pipeline order for how the enhanced profiles are processed... also, in terms of the DNG spec you referenced, I believe the ToneCurve it is referencing step 8 is the ToneCurve parameter embedded into the base .dcp profile - it makes no mention of the order all the available tone curves (and color curves) inside Lightroom itself, and what order those are applied in.  
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Cameron Rad

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RGB LUTs are applied near the end of the image processing pipeline. HSV Look Tables get applied right after the DCP profile.
(Edited)
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Todd Shaner, Champion

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"I believe the ToneCurve it is referencing step 8 is the ToneCurve parameter embedded into the base .dcp profile - it makes no mention of the order all the available tone curves (and color curves) inside Lightroom itself, and what order those are applied in."

It's pretty clear that the LR Tone Curve panel settings are applied dead last in the pipeline as shown in the below example. Changing ANY of the other Develop module controls has no affect on the Histogram Black and White endpoints. Concerning the other tone curves I have no idea, but there was a similar issue with the Global and Local settings order. LR 4 and earlier versions applied the Local controls first followed by the Global controls. If the Local controls forced the image into highlight clipping the Global controls could not recover the clipping. This was corrected in LR 5 or 6 so the Local and Global controls are summed (non-linearly), which allows recovering highlights highlight. As you've outlined there appears to be a similar issue with the new enhanced profiles. More here: https://forums.adobe.com/message/4613624#4613624


(Edited)