Contrast adjustment in RGB mode saturation increase

[Mark D Segal]

Well, given what the manual says, the FAQ is not completely wrong in a literal sense: you can start with an RGB file, but you need to use their application in LAB. One or the other source is more accurate, and I would assume it is the manual, in which case the FAQ needs added accuracy.

[Mark D Segal]

.......and if the Manual prevails, you'll notice the added gymnastics needed to work the photos "non-destructively". I'll stick with LR, thanks.

[digitaldog]

I know a number of people in my direct circle who are colorblind (like about 8 percent of males, and 0.5 percent of females)...

First, if someone is 'colorblind' they've got all kinds of issues editing and evaluating images, you're suggestion for Contrast isn't going to help (or necessarily hurt). They are colorblind!
Next, the value of 8 percent, at least according to Fairchild/Hunt for the 3 most common types of color-vision deficiencies are far lower as you can see here (the top three Protanopia, Deuteranopia and Tritanopia):

[digitaldog]

.......and if the Manual prevails, you'll notice the added gymnastics needed to work the photos "non-destructively". I'll stick with LR, thanks.

For most images, so will I. But this looks like an interesting tool for some circumstances. Downloaded the demo. Need time to play.

[Mark D Segal]

OK, once you've played perhaps start a new thread telling us what you think of it.

[TRANTOR]

Internally FireGrade works in Lab/Lch with double float precision. Input image (or layer) can be in RGB of course. Conversion to Lab and back to RGB depends on your Photoshop color conversion settings.

Unexpected results may be get in some special cases. For example, in conversion chains like ProPhoto -> Lab -> ProPhoto some (imaginary) color will be lost, because ProPhoto is XYZ-profile that have wider gamut than Photoshop's Lab. Plus, visualization may be differ in preview window because Photoshop uses different gamut mapping for "RGB -> XYZ monitor profile -> monitor RGB" and "Lab ->  XYZ monitor profile -> monitor RGB".


PS. Sorry for my bad english.

[brandon]

Contrast IS fine. And yes, I and I suspect tens of thousands of users are happy with this behavior. Of course, every couple years, we hear this old debate (started I believe last century by Dan Margulis). It goes nowhere. Don't like the behavior? Find another product. Or figure out how to use the product to get the results you like if possible (like the massive audience for this product) Or do your due diligence to try to convince Eric or Thomas of their 'errors'.
You want independent research or reports? Use 'the Google' or check out the various Adobe sites where customers spend vastly more time writing about problems that really DO need to be addressed. This is small beans. Great. Then time to move on. Those who are happy with this aspect of the product will do the opposite.
You want me to outline my issues and disappointment with LR? I've got plenty. That Contrast affects Saturation and makes the images look better to me isn't one of them!

Come on the OP was about understanding the effect of contrast changes (or "inputs" from the so named slider) on saturation not about whether someone is happy 90% of the time that contrast changes colour and being generally dismissive of discussion about why its like that and why (and how) it need not be. Thanks to those who are explaining (and illustrating) the effects and helping  those of us who know less to understand more about colour management, and perhaps suggesting to those who may be in a position to enhance existing products (Eric's comment suggests it might be something for LR, as indeed similar functionality has been implemented in CaptureOne from vers 9 recently). More light less heat please as befits the name of this website., Regards Brandon

[digitaldog]

Thanks to those who are explaining (and illustrating) the effects and helping  those of us who know less to understand more about colour management....

IMHO, this has nothing to do with color management. It does have to do with how differing software products and their designers code controls to alter image appearance. And that's subjective.

[Peter_DL]

This is also very much my experience not only from every day work on photographs, but also from the extensive testing I did of this issue and related matters nine years ago.

Indeed it is an old debate.

For me, the subject is more prominent again since PV2012. PV2012 allows me to apply some extra punch (contrast) while preserving the shadow and highlight details with the corresponding 'new' controls. Fine. But then, this is where the saturation tends to get out of proportion, particularly in the shadows. I can't see these blue-inked mountain-shadows anymore. At least that's my perception.

By nature it seems to be a quite controversial subject. For example, here is a earlier thread which turned into an argument if it is beautiful photos or badly over-saturated. At some point the OP stated : >>The saturation in my images comes as a side effect of making the contrast and exposure and other light adjustments.<<. So here we are again.

I think the relevance is higher than "9:1", higher than the awareness. Who knows.
We'll see if/how Adobe addresses the subject.

An easy solution would probably be to furnish the HSL tab(s) with a selection for the tonal range -> shadows, midtones, lights, all. Could be useful for other things as well.

Peter
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[Bart_van_der_Wolf]

IMHO, this has nothing to do with color management.

I somewhat agree, although I suppose that maybe Brandon didn't mean Colormanagement as such, but rather the management of the process of colorediting (such as the effects of adjusting Contrast on color).

But it is also not totally detached from colormanagement, depending on how things are implemented. The quotes from Anders Torger mentioned the effects of initial saturation boosts and how they are handled when rolling off towards clipping in a given colorspace. That could be mostly reversible, if the processing was done in floating point numbers, but AFAIK it usually is not.

It does have to do with how differing software products and their designers code controls to alter image appearance. And that's subjective.

Well, it's more the tolerance a person has for the Saturation changes. That tolerance is subjective. The fact that Saturation changes, or not so much, or is controllable, is factual, and fixed in the code that was written to do the conversions. And that is pretty objective, because it has to be repeatable.

Cheers,
Bart

[Mark D Segal]

Indeed it is an old debate.

.........................
We'll see if/how Adobe addresses the subject.


Peter
--

Given how old the debate is, I think there has already been enough time for Adobe to consider the merits of these arguments and the application we have is the net result of whatever they have considered to date. My own guess is that if in their view the clientele for delinking saturation from contrast was large enough, the option would have been programmed in by now. Not to say as time goes on they won't be further refining LR's Develop Module, but the extent of priority to or modification of this one item does indeed remain to be seen.

[brandon]

I suppose that maybe Brandon didn't mean Colormanagement as such, but rather the management of the process of colorediting (such as the effects of adjusting Contrast on color).

But it is also not totally detached from colormanagement, depending on how things are implemented. The quotes from Anders Torger mentioned the effects of initial saturation boosts and how they are handled when rolling off towards clipping in a given colorspace. That could be mostly reversible, if the processing was done in floating point numbers, but AFAIK it usually is not.

Yes exactly Bart, that is what I was referring to the management of colour when manipulating our raw images, which is after all what "Digital Image Processing" threads cover. An understanding of the behaviour of the tools, not peoples second guessing whether Adobe will or wont change it in future or it suits them is where the learning isand valuable sharing of information on in a forum is. Thanks for as always adding considerably to these pursuits.
Cheers Brandon

[bjanes]

First, if someone is 'colorblind' they've got all kinds of issues editing and evaluating images, you're suggestion for Contrast isn't going to help (or necessarily hurt). They are colorblind!
Next, the value of 8 percent, at least according to Fairchild/Hunt for the 3 most common types of color-vision deficiencies are far lower as you can see here (the top three Protanopia, Deuteranopia and Tritanopia):

Protanopia and Deuteranopia subjects are not really color blind. They are dichromats and lack one of the three types of color receptors, red in the case of protanopia and green in the case of deuteranopia (see Wikipedia). The proofing setup of Photoshop can simulate how colors are perceived by these subjects. The simulation for protanopia is shown below; the magenta flower appears blue, since the red component of magenta is not visualize. These deficiencies affect about 1% of male subjects.

Protananomaly and deuternamaly, affecting 1% and 5% of male subjects respectively, are trichromats whose red or green receptors have a shifted color response. These defects are relatively mild. Photoshop has no proofing for these cases, and the degree of shift in the photo pigments may vary from case to case.

Bill

[digitaldog]

Protanopia and Deuteranopia subjects are not really color blind.

Tell Bart   
You'll notice I used quotes and italics for that term, and uploaded text from Hunt/Fairchild with their percentages for which they call color vision deficiency.

[Tim Lookingbill]

>>The saturation in my images comes as a side effect of making the contrast and exposure and other light adjustments.<<.

There's a lot more going on to influence the saturation levels in Hans' images than just contrast and exposure adjustments.

Saturation appearance may need to be more exaggerated on one particular element to express the fluorescing effect (sunsets clouds) as a reflection of the spectral response of the light while the rest of the scene elements getting less light should be less saturated. It can't be all equally saturated to look like a Mondrian painting.

Just because someone wants to render and reduce the dynamic range of a landscape to look like an Ektachrome slide with deep dark (near black) shadows and saturated mids & highlights is not the fault for the lack of control over contrast induced saturation in the design of the software.

Has anyone in this thread tried to reduce saturation moving ACR/LR's simple Saturation slider to the left? No ruddy and cooked greens or dead looking colors.

[Mark D Segal]

Has anyone in this thread tried to reduce saturation moving ACR/LR's simple Saturation slider to the left? No ruddy and cooked greens or dead looking colors.

While I seldom find it necessary to reduce overall saturation as a function of a contrast increase, periodically I would notice a particular colour range that could do with a bit less saturation, hence I would go to the HSL panel and do it selectively there; for general saturation reduction, reducing Vibrance is "saturation reduction smart" because positive or negative its impact varies according to the extent of saturation it is dealing with. The saturation slider is more useful for "generalized heavy lifting".

[Tim Lookingbill]

While I seldom find it necessary to reduce overall saturation as a function of a contrast increase, periodically I would notice a particular colour range that could do with a bit less saturation, hence I would go to the HSL panel and do it selectively there; for general saturation reduction, reducing Vibrance is "saturation reduction smart" because positive or negative its impact varies according to the extent of saturation it is dealing with. The saturation slider is more useful for "generalized heavy lifting".

I find backing off the Vibrance slider lightens blues, violets and greens in flowers. The Saturation slider show far less effect to a degree over a wider range of colors.

[Tim Lookingbill]

Peter's mentioning missing inky blue mountain shadows switching to PV2012 corroborates what I experienced but I found it was more caused by the camera profiles made with the newer DNG Profile Wizard (for my camera) where now I get results that are similar to Adobe Standard where the overall WB appears less saturated and more neutral across the tonal scale of the image. Skin tones take on a slight bluish rust tint in micro contrast skin texture as in wrinkles and knuckle shadows.

The one reason I stick with my old custom DNG Profile Wizard camera profiles.

[Bart_van_der_Wolf]

Given how old the debate is, I think there has already been enough time for Adobe to consider the merits of these arguments and the application we have is the net result of whatever they have considered to date. My own guess is that if in their view the clientele for delinking saturation from contrast was large enough, the option would have been programmed in by now. Not to say as time goes on they won't be further refining LR's Develop Module, but the extent of priority to or modification of this one item does indeed remain to be seen.

Hi Mark,

I suppose it's anybody's guess why they do not address this, but I would not be surprised if the lack of a budget for addressing this issue might also have something to do with it. The engineers can only do those things that they get a budget for, and they are not the ones to prioritize that allocation. So it would take some very strong push-back to get general management to change that situation. It is my impression that the power of the engineers at Adobe isn't what it used to be.

But indeed, we'll see what the future brings.

Cheers,
Bart

[Schewe]

It is my impression that the power of the engineers at Adobe isn't what it used to be.

As it relates to Thomas Knoll and the ACR/LR Develop module, you would be incorrect. Thomas pretty much has free reign to do pretty much anything the ACR team really wants to do. How do you explain HDR and Pano going into ACR when it's also already in Photoshop? Why?. Because Thomas wanted it there.

No, your argument is wrong...if Thomas wanted to change the Contrast algorithm, he would do so. The fact he hasn't means the argument for changing it has failed to get traction to make it worth his (and the ACR team's) efforts.

It would require an all new Process Version and I think it's simply not worth the effort.