Luminous Landscape Forum
Raw & Post Processing, Printing => Digital Image Processing => Topic started by: larkis on June 22, 2016, 08:05:15 pm
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I would like to find some information that gives a non math formula explanation of why a contrast adjustment in RGB space also increases the image saturation vs doing the adjustment in LAB space or using a layer adjustment set to luminosity. Is there a website that helps visualize some of this ? I'm mostly curious of my own education.
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There is no necessary mathematical reason for the Tone Curve or other contrast tool to change saturation with a change in contrast when adjusting photos in an RGB colour space. The Photoshop developers programmed it this way intentionally because the tonality looks more natural and pleasing adjusted in that manner. Try increasing contrast without increasing saturation, as you can do with the Luminosity blending mode, and you will see immediately the rationale. But there are ways to moderate that behaviour using layers and blending modes to suit your taste.
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There is no necessary mathematical reason for the Tone Curve or other contrast tool to change saturation with a change in contrast when adjusting photos in an RGB colour space. The Photoshop developers programmed it this way intentionally because the tonality looks more natural and pleasing adjusted in that manner. Try increasing contrast without increasing saturation, as you can do with the Luminosity blending mode, and you will see immediately the rationale. But there are ways to moderate that behaviour using layers and blending modes to suit your taste.
Interesting, so how did the photoshop developers accomplish the saturation boost ? I see other tools behave in a similar way. Interesting that this is not a byproduct of working in the RGB space, thank you for that tidbit of information.
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Interesting, so how did the photoshop developers accomplish the saturation boost ?
It's all in the higher mathematics of digital imaging and programming - not my field.
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From an older post by Eric Chan of Adobe (san's math):
Eric Chan wrote:
Thomas and I separately explored the side effects and implications of various tone curve implementations (he in the early days of Camera Raw, I when working on color profiles in 2008 and again in 2010). I learned a few things along the way.
One is that contrast and saturation are often correlated in the real world, which is why an increase in contrast often (though not always) works well with an increase in saturation. Clarity is an example of a contrast control that doesn’t obey this: it allows you to increase/decrease (local) contrast while preserving saturation. If you’ve ever tried a strong negative Clarity adjustment on a colorful image, the result looks a bit odd. Similarly, if you’ve taken a rather pale image and added strong positive Clarity but without punching up the Saturation/Vibrance controls, the result also tends to be artificial. So we’ve not been entirely consistent in how we’ve dealt with saturation side effects in our contrast controls, but I’d probably give the nod to Thomas’s design (saturation side effect).
A second lesson is that the choice of color space makes a big difference to the result. As Jeff, Andrew, and others have widely documented, we use ProPhoto as our choice of RGB primaries, which is a good thing in many cases. For saturation side effects in curves, though, there are some issues. In particular, due to the position of the blue ProPhoto primary, this means our current tone curve tends to have much stronger blue saturation side effects than in other hues. In particular, if you have a typical S curve or just increase the Contrast control, darker blue tones (such as first column, third row of a standard ColorChecker, or deep blues in water reflections) tend to get overly saturated, and lighter blue tones (such as skies) tend to become overly desaturated. There are ways to get the saturation side effects to be more perceptually uniform, and I’m investigating those for the future (would likely require a process version bump, though).
A third lesson is that our current color control set within the ACR/LR UI isn’t really good (yet) for doing 3D color edits. This is because one cannot fully control how hue and saturation are affected as a function of lightness (or brightness, or luminance, or whatever term you want to use). For example, when you use HSL controls to change the Orange hues, that changes them for all orange hues, light and dark. You can’t change them separately for light vs dark hues. It is possible, of course, to use per-channel RGB curves to bring back Photoshop-style hue twists in tone curves, but even though you don’t have full control over how those twists behave.
And finally, yes, part of film’s charm (or curse, depending on your point of view!) is the fact that it’s rather non-linear in behavior, so you do get various twists or distortions in hue & saturation as a function of exposure.
Eric
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I remember reading a story once about the very early development of Photoshop 1.0. Back when not much was known about digital processing and everyone was learning "on the go". The story said when the "Levels" logic was first written it was very simple math. But Knoll and others argued, some saying colors just didn't "look right".
That first "Levels" was what we call Luminosity mode today. Code was then added to adjust saturation along with brightness. Some felt that didn't look right either. I can't remember which side of the argument Knoll was on. The argument was settled by leaving both methods available, and that's how Luminosity mode was invented.
So a simple answer to why saturation changes when tones change is that otherwise, it just does not look right.
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Brightness is a perceptual phenomena. Luminance (Luminosity) is a measure of the total radiant energy from a body. It has nothing to do with what a human perceives but rather describes the total radiant energy, such as watts/second of a source (the surface of a radiating object like a display). In Photoshop, the layer mode called luminosity is not what's occurring (I was told its something like the "Luma" which is an old TV RGB transform). If the luminance of a viewed light source is increased 10 times, viewers do not judge that the brightness has increased 10 times.
Lightness is a perceptually scaled component of color, the axis seen in Lab (Lstar) from light to dark. It IS the L in HSL.
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So a simple answer to why saturation changes when tones change is that otherwise, it just does not look right.
Hi,
However, some argue that the way it's implemented (sometimes) does not look right (and it's destructive), and I'd agree. That's why I prefer the ability to choose the level of saturation change myself, like implemented in a number of Topaz Lab plugins that use "Intellicolor technology". Here's a comparison (https://www.youtube.com/watch?v=s_YAavRntPo).
Cheers,
Bart
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Bart - I have nothing against plug-ins per se, but just to remind that it is also possible to quite easily control setting contrast and saturation independently in Photoshop.
Andrew - thanks for pulling up that discussion from Eric - very insightful, and confirms that for the most part these are (sensible) programming choices rather than mathematical inevitability.
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Bart - I have nothing against plug-ins per se, but just to remind that it is also possible to quite easily control setting contrast and saturation independently in Photoshop.
Hi Mark,
I know, but unless one applies contrast adjustments on a Luminosity blending layer, Saturation is affected with no other control than a second correction in reducing the saturation is some parts of the image and increasing it in others. The artifacts will by then be amplified and baked into the composited image. I think that Eric Chan's initial preference, before he gave in, is best from a solid processing point of view.
Cheers,
Bart
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Hi Mark,
I know, but unless one applies contrast adjustments on a Luminosity blending layer, ...........
Cheers,
Bart
OK, but there is nothing preventing one from doing this. The Plug-in probably just makes it more convenient.
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...... In Photoshop, the layer mode called luminosity is not what's occurring (I was told its something like the "Luma" which is an old TV RGB transform). ......
The definition of what the Luminosity blend mode does, from Fraser/Blatner in "Real World Photoshop CS2", page 357: "Luminosity is the inveree of Color. It creates a result color with the hue and saturation of the underlying color and the luminosity of the overlying color".
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OK, but there is nothing preventing one from doing this. The Plug-in probably just makes it more convenient.
The artifacts are probably a result of the rudimentary processing. They won't go away.
The plugin video that I linked to, was for the purpose of showing the low quality that the default (contrast+saturation) controls produce, and that it is possible to avoid issues by using better technology. Thomas Knoll may be a smart guy and a good programmer, but he is not God. Some of his compromise solutions deliver sub-par quality, sad but a fact.
Cheers,
Bart
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The artifacts are probably a result of the rudimentary processing. They won't go away.
The plugin video that I linked to, was for the purpose of showing the low quality that the default (contrast+saturation) controls produce, and that it is possible to avoid issues by using better technology. Thomas Knoll may be a smart guy and a good programmer, but he is not God. Some of his compromise solutions deliver sub-par quality, sad but a fact.
Cheers,
Bart
So you thought the first demo of that video of reduced saturation and charcoal black shadows adding contrast to the woman in a dark red dress looked better than the LR version? That's higher quality technology to you? I won't be using that technology anytime in the near future.
The real flaw of that video is that they use perfectly good looking, well finished images to start with that don't need editing. I didn't see any need to use a third party plug-ins on those images. As someone with a background in making pictures look good and communicate well I have to say that's a bad way to sell a piece of software.
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So you thought the first demo of that video of reduced saturation and charcoal black shadows adding contrast to the woman in a dark red dress looked better than the LR version? That's higher quality technology to you? I won't be using that technology anytime in the near future.
Hi Tim,
Of the two, the second example does look more natural, although personally I'd add some saturation at my discretion and control. Given that I would not first introduce artifacts before dialing down, if at all possible, that is a vastly more robust mode of operation. I'm a bit surprised that you apparently cannot distinguish between a demonstration of differences and an example of good post-processing. Nichole Paschal (the presenter) also said that the amount of the adjustments was too much.
One could return the question, do you think the first example looked better in Lightroom? But I won't ask such a silly question.
The real flaw of that video is that they use perfectly good looking, well finished images to start with that don't need editing. I didn't see any need to use a third party plug-ins on those images. As someone with a background in making pictures look good and communicate well I have to say that's a bad way to sell a piece of software.
Again, it's not a tutorial about how to process an image, but a technology demonstration, which is usually made clear by exaggerating the settings and see how well it stands the abuse before producing artifacts.
If you really have a background in making pictures look good, then you should know that RGB brightness/contrast adjustments usually also change saturation (because chromaticity and luminosity are not separated), and that it doesn't look good, requiring additional adjustments. In that case, why first change the saturation by the wrong amount, having to correct it in a second adjustment. And you should then also know that first over-saturating makes it perceptually more difficult to then create the 'correct' setting than starting from a more neutral setting, even if the artifacts can be avoided.
Cheers,
Bart
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If you really have a background in making pictures look good, then you should know that RGB brightness/contrast adjustments usually also change saturation (because chromaticity and luminosity are not separated), and that it doesn't look good, requiring additional adjustments. In that case, why first change the saturation by the wrong amount, having to correct it in a second adjustment. And you should then also know that first over-saturating makes it perceptually more difficult to then create the 'correct' setting than starting from a more neutral setting, even if the artifacts can be avoided.
Cheers,
Bart
Bart, at the risk of being repetitive, the reason why Contrast and Saturation move "in-sync" is not because they need to, but because the team of programmers, QC people and decision-makers in charge of what actually comes to users decided on the algorithms that should be satisfactory to the vast majority of their clientele. Which means that a high percentage of photographs processed in this manner are acceptable to a high percentage of the users. If they were not, and if there were a ground-swell of complaints coming to Adobe about excessive saturation resulting from increased contrast, the algorithms would have been tweaked. They aren't unresponsive dummies. If data were available, I would be surprised if more than a real minority percentage of the total number of photographs run through PS and LR in the world had their saturation dialed-back as a result of an increase in contrast. So let's keep things in perspective.
My own personal taste for LR would have been to start with a linear rendition and dial-in my own contrast and saturation, but the company has reasons, looking at the community as a whole, to do it otherwise. And really, at least at the LR or ACR stage of editing, no harm one way or another, because whether the controls are dialed up or dialed down, and no matter how many times you dial this way or that, it does NOTHING to the technical integrity of the image data because it is all metadata and any conversions include only the last instruction retained for any one of those controls. And if you don't like the rendered result, you still have the non-destructive aspect of going back to the raw file in whatever state you processed it, especially in LR where all the editing steps are retained by default unless eliminated in one way or another.
I'm not saying all this is much ado about nothing, but it may be fair to characterize the issue as "some ado about not very much". :-)
Cheers
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Thomas Knoll may be a smart guy and a good programmer, but he is not God.
Not god but he is the father of this industry so a tiny bit of respect might be due.
If you don't like the way ACR/LR work, you are always welcome to use that other imaging app he created called Photoshop where's it's very, VERY easy to adjust contrast without adjusting saturation. Oh, wait, Nichole Paschal knows how to work in Photoshop too! Maybe she could create a contrast adjustment level and set it to luminance blending. Bet she could make IntelliColor™ look like Photoshop :~)
Personally, I thought her demo sucked because based on the video I saw, the LR image looked much better–although I doubt that the image needed just "a bit of adjustment" to +46 Contrast...(just a bit, really?) Oh, and I loved the way IntelliColor™ made the maroon dress look black.
Sorry nothing about that video says Thomas is wrong.
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...If data were available, I would be surprised if more than a real minority percentage of the total number of photographs run through PS and LR in the world had their saturation dialed-back as a result of an increase in contrast. So let's keep things in perspective.
ACR/LR's global saturation slider is definitely not designed and programmed by dummies. I often move that slider to the left a bit just to override the contrast induced saturation boost. Luminance and most of the color hues are retained unlike the Vibrance slider.
Wish HSL panel behaved like the saturation slider when I use its sliders to reduce saturation on overly rich blue skies and shaded whites and grays.
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Sorry nothing about that video says Thomas is wrong.
Or that a lot in the video is right or necessary/useful. I admit I watched half and gave up. After the bit about the display(?) of a super, super saturated tweak presumably causing banding in both awful appearing images, more in PS I knew I'd seen enough.
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Just a note about that video I find a bit telling. It was posted to YouTube in 2012 and yet there are no comments after 4 years. That's very unusual for an image editing software that claims to have "advanced technology".
I'ld expect the typical Twitter and Facebook styled insipid one liners either praising or condemning it, but to not have one comment makes it appear not too many are interested. I mean there's more interest in $3 bottle of Merlot sold at Walmart on YouTube. "Oak Leaf" I highly recommend BTW.
Maybe the folks that posted the video should get some marketing bots to write some comments to liven up the place.
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There is no necessary mathematical reason for the Tone Curve or other contrast tool to change saturation with a change in contrast when adjusting photos in an RGB colour space. The Photoshop developers programmed it this way intentionally because the tonality looks more natural and pleasing adjusted in that manner.
Mark, - The mathematical explanation why RGB tone curves also change color saturation is not particularly difficult. We can delve into the equations (if you want so), but it is simply a side effect of the per-RGB-channel-application of the curve, which alters the R:G:B intensity ratios per color depending on the shape of the curve.
Peter
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Mark, - The mathematical explanation why RGB tone curves also change color saturation is not particularly difficult. We can delve into the equations (if you want so), but it is simply a side effect of the per-RGB-channel-application of the curve, which alters the R:G:B intensity ratios per color depending on the shape of the curve.
Peter
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And add to that the nonlinear behavior of backlit RGB displays per channel intensity ratios as the curve within the software sends varying levels of voltages to make each RGB combo bright or dark through the video card and onto the display's RGB subpixels. With this level of complexity it's a wonder we see anything close to looking like what we captured with our cameras.
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With this level of complexity it's a wonder we see anything close to looking like what we captured with our cameras.
It's why we don't. What our cameras produce don't look anything like what we're seeing or what we get!
(http://www.digitaldog.net/files/raw.jpg)
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There is no necessary mathematical reason for the Tone Curve or other contrast tool to change saturation with a change in contrast when adjusting photos in an RGB colour space. The Photoshop developers programmed it this way intentionally because the tonality looks more natural and pleasing adjusted in that manner. Try increasing contrast without increasing saturation, as you can do with the Luminosity blending mode, and you will see immediately the rationale. But there are ways to moderate that behaviour using layers and blending modes to suit your taste.
This isn't what I see when I look at how the curves work. It seems like a very simple implementation that does exactly what it says: applies a curve equally across each channel. An increase in saturation is a natural consequence of this. The greater the ratio between the dominant (highest) channel and the lowest channel, the higher the saturation (in Photoshop's implementation). When you apply an S-curve this ratio increases where the curve is steeper, which in turn increases the saturation. That doesn't mean it wasn't a conscious choice by the Adobe engineers, but it is also a natural consequence of the simplest implementation you could use.
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It's all in the higher mathematics of digital imaging and programming - not my field.
There's not a lot of higher mathematics going on here. Take the the smallest RGB value and divide by the biggest. Subtract that value from 1 and you have what Photoshop reports as saturation. For example RGB(189, 37, 60) - Saturation is 1-(37/189) = 0.804. Photoshop reports 80% Knowing this you can see how a curve that increases contrast will also increase saturation.
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Mark, - The mathematical explanation why RGB tone curves also change color saturation is not particularly difficult. We can delve into the equations (if you want so), but it is simply a side effect of the per-RGB-channel-application of the curve, which alters the R:G:B intensity ratios per color depending on the shape of the curve.
Peter
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There could be both intent and side effects at play, depending on the specific aspect at hand. Please see post #4 above.
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That doesn't mean it wasn't a conscious choice by the Adobe engineers, but it is also a natural consequence of the simplest implementation you could use.
OK, we agree that the behaviour *could have been* a conscious choice of the Adobe engineers. Not being a digital imaging programmer or an Adobe employee I certainly have no feel for how simple or complex their implementation is, but thanks for the insight into the simplest one. At that level, I agree, we're dealing with some pretty basic arithmetic, but there could be more to it. Anyhow, I think the important point of the discussion to retain is that we are not locked-in to any particular implementation. We have the tools in both LR and PS to dial-in just about whatever combination of saturation and contrast that suits us. For practical purposes that would satisfy most results-oriented folks who are less concerned about how Adobe did their thing under the hood, and more focused on what we can do with the applications over the hood.
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With this level of complexity it's a wonder we see anything close to looking like what we captured with our cameras.
In addition to Andrew's comment that's why the quality of the demoasaicing process, camera profiles and colour management of our displays and printers is so important. And yes, I agree, how stringing all this stuff together allows us to produce such high quality photographic renditions is indeed wonderful, and a tribute to the groups of engineers and programmers who made it possible.
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In addition to Andrew's comment that's why the quality of the demoasaicing process, camera profiles and colour management of our displays and printers is so important.
Tim also needs to study up on the concept of cameras and their significant observer metamerism compared to humans and their behavior with respect (or lack thereof) of the the Luther-Ives condition.
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Very simple example:
R=150
G=100
B=100
is a reddish tone because it has more Red than Green and Blue. If we apply a typical contrast curve in RGB blend mode:
(http://www.guillermoluijk.com/article/acrps/contraste_ps2.gif)
R gets higher than 150 and both G and B lower than 100, let's say:
R=160
G=90
B=90
What is that? another reddish colour where R is more apart from G and B than in the begining, i.e. a more saturated reddish colour.
I have to say that most times RGB blend mode curves work better than Luminance blend mode in PS. RGB saturates but Luminance unnaturally desaturates.
Lab is not perfect either. It can't be, it's just a good model but in the real world you can always add more red light while Lab can't help to desaturate when increasing its L* for being limited in a closed range of values:
(http://www.guillermoluijk.com/article/ettrcolor/bombillas.jpg)
Just to finish, this kind of straight curve is the only one that can implement a change in exposure over any linear or pure gamma image:
(http://www.guillermoluijk.com/article/acrps/exposicion_ps.gif)
Curiously it has to be applied in RGB blend mode or saturation and hue changes will take place. In RGB it mimics a change of exposure in the camera (no hue/saturation change, R/G/B ratios are preserved).
Regards
www.guillermoluijk.com
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This isn't what I see when I look at how the curves work. It seems like a very simple implementation that does exactly what it says: applies a curve equally across each channel. An increase in saturation is a natural consequence of this. The greater the ratio between the dominant (highest) channel and the lowest channel, the higher the saturation (in Photoshop's implementation). When you apply an S-curve this ratio increases where the curve is steeper, which in turn increases the saturation. That doesn't mean it wasn't a conscious choice by the Adobe engineers, but it is also a natural consequence of the simplest implementation you could use.
Mark is correct, neither mumbo jumbo nor genius are required, it is just a direct consequence of a simplistic implementation of a contrast change in RGB colorspace.
And in the process of fanboyism (it's so much easier to criticize others than admit shortcomings in one's own processing tools) from some of the contributors for the dated way of image editing, people may also have missed one of the improved features (http://blog.phaseone.com/capture-one-9-under-the-hood/) of Capture One version 9, an improvement of the Contrast, Brightness, and a little improvement of the Saturation controls, and of the way they interact. Also the R/G/B and L curve controls are a huge improvement. Luma can be separately used for contrast adjustment curves, and simultaneously now more subtle R/G/B curves adjustments can be applied.
I must say that these controls now allow for a much faster workflow in adjusting the overall look, while maintaining robust color quality. We no longer get very over- or under-saturated colors when contrast is adjusted. Prior to this version upgrade, it used to require multiple corrections (which is why many hardly used those controls) to get the saturation back to where it looked best, now only a simple contrast or brightness adjustment is often enough.
Also skin colors retain their healthy look despite even strong adjustments in contrast, which allows to shoot in softer, more balanced light, and add contrast in post (knowing that the camera could capture more of the original color without underexposure noise or overexposed highlights, and contrast changes no longer screw up colors).
Cheers,
Bart
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Mark is correct, neither mumbo jumbo nor genius are required, it is just a direct consequence of a simplistic implementation of a contrast change in RGB colorspace.
Well, well: I'd be interested to know how you know this. Are you a programmer of Photoshop? Have you seen the math they used, studied their algorithms? I haven't, but I'm just asking on what authority you are making this statement. Implicit in your statement is the notion that they don't know any better, hence the use of the word "simplistic" rather than just "simple", as opposed to more complex. Suppose they did opt for a simple implementation of the relationship - if that's the effect they wanted to produce, what's wrong with it? You only add complexity as needed/wanted.
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And in the process of fanboyism (it's so much easier to criticize others than admit shortcomings in one's own processing tools)
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Why are you trying to impute irrational motives to a technical discussion? Different people are entitled to a different opinion, based on their knowledge and working experience about how the tools in this or that application perform without being "fanboys", are they not?
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............the dated way of image editing, people may also have missed one of the improved features (http://blog.phaseone.com/capture-one-9-under-the-hood/) of Capture One version 9, ..........
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What is this dated way of image editing? Some things that are dated are just fine, others deserve improvement. The time since an algorithm was developed can be truly irrelevant if it still works well and does the job people want and expect of it, especially as in this case all kinds of things are refined under the hood with every upgrade. If it doesn't continue to work well and something better comes along, only then does it become dated. Now as for Capture 9 - sure - a very high quality application, I agree with you; A professional who knows it inside-out demoed it to me in detail late last year and I think it has some very attractive and tempting features. But for the time being I am remaining with LR for other reasons, an important two of which are (1) it's well-integrated workflow capabilities, and (2) with every upgrade it delivers more and more new features that provide the results I find photographically satisfying. I just don't see the incremental benefits relative to the incremental costs of renovating my whole digital imaging environment, as such as change would require.
For me, Bart, the bottom line is that a raw file is a raw file and will need adjustment no matter what it's starting point. I have never opened a raw file in the past twelve years that I have been shooting raw that didn't need adjustment regardless of the camera or the editing application. For me, LR and as needed Photoshop provide what I need to make high quality photographs with the luminance, hues and saturation values I want for the photo at hand. There are areas for improvement in LR I'm aware of that haven't been addressed in this thread, but they are OT relative to the question the OP raised. I know there are other applications out there with which one can do likewise, perhaps some more easily than others, but that is a different question. And by the way, this is not a new topic; the contrast/saturation linkage issue has a pedigree going well back in time; people agreed to disagree back then and this will probably continue to be the case indefinitely. With this, I think I have put in about the amount of time I can give to this thread. La Lutta Continua (probably without me)!:-)
Cheers.
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OK, we agree that the behaviour *could have been* a conscious choice of the Adobe engineers.
Well, I'll confirm that it was a conscious choice of one engineer, Thomas Knoll. He didn't do curves this way because it was "simpler" or "easier" or "faster" but because the curves algorithm as it is in Photoshop and Camera Raw looked better to him (they are, or course different algorithms but written to achieve similar results). In fact, Thomas tried several (if not many) different algorithms before finally settling on the way curves work now in PS/ACR.
One can argue that different methods produce different results and sometimes some results are better than other results depending on the images and what is needed to adjustment. But to argue one method is antique and "modern" methods are better (presumably because they are newer) is pretty naive and is letting a bit of an anti "something" to show through...PS/ACR/LR do things a certain way...if you like the results, keep learning how to use them better.
If you don't like the results Bart, feel free to use something else. But calling somebody a fanboy is really kinda juvenile in any reasonable debate or discussion. It pretty much works against you and your argument–particularly when the video you claimed showed a better way was such a piece of crap. You have yet to prove your point regardless of the hand waving you've been doing :~)
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Well, well: I'd be interested to know how you know this. Are you a programmer of Photoshop? Have you seen the math they used, studied their algorithms? I haven't, but I'm just asking on what authority you are making this statement.
Hi Mark,
Thanks for the honest questions. Obviously I'm not an Adobe programmer but, besides the in my eyes glaringly wrong output, it is not that difficult to reverse engineer what is happening under the hood. So yes, I've studied the behavior of what their algorithms do, and they basically just apply a standard (sort of S-curve) contrast transform in the RGB space. It doesn't look like they do much else, because I can replicate the effect (not that I'd want to in actual image processing) by using a mathematically similar curves adjustment to all three R/G/B channels.
Implicit in your statement is the notion that they don't know any better, hence the use of the word "simplistic" rather than just "simple", as opposed to more complex. Suppose they did opt for a simple implementation of the relationship - if that's the effect they wanted to produce, what's wrong with it? You only add complexity as needed/wanted.
Sure, it is a slightly exaggerated qualification, meant to snap people out of their non-critical state of worship. Shock therapy as it were. The choice to implement it as they did is apparently deliberate, and it was immediately questioned/challenged, or so it seems from the earlier quoted text, by a very clever guy Eric Chan whom I think highly of.
Why are you trying to impute irrational motives to a technical discussion? Different people are entitled to a different opinion, based on their knowledge and working experience about how the tools in this or that application perform without being "fanboys", are they not?
Shock therapy ...
What is this dated way of image editing? Some things that are dated are just fine, others deserve improvement.
Non-intelligent e.g. contrast adjustments are a dated way. And there is a reason why Photoshop allows Luminosity blended adjustment layers ..., they do know that the current implementation sucks, unless one uses very small amounts (where the errors will be less visible).
The time since an algorithm was developed can be truly irrelevant if it still works well and does the job people want and expect of it, especially as in this case all kinds of things are refined under the hood with every upgrade. If it doesn't continue to work well and something better comes along, only then does it become dated.
Not really, it was a compromise from the get go, and speed of execution was deemed more important than higher perceptual accuracy.
Now as for Capture 9 - sure - a very high quality application, I agree with you; A professional who knows it inside-out demoed it to me in detail late last year and I think it has some very attractive and tempting features. But for the time being I am remaining with LR for other reasons, an important two of which are (1) it's well-integrated workflow capabilities, and (2) with every upgrade it delivers more and more new features that provide the results I find photographically satisfying. I just don't see the incremental benefits relative to the incremental costs of renovating my whole digital imaging environment, as such as change would require.
I understand that, but that's all the more reason to send a very clear message that these antiquated tools need to be improved, like their competion has been doing for years, and finally C1 also made the next step. Late, but better than never. I have not yet looked at Affinity Photo (because it's not yet available for Windows), but it would not surprise me if they also use a more intelligent approach.
For me, Bart, the bottom line is that a raw file is a raw file and will need adjustment no matter what it's starting point. I have never opened a raw file in the past twelve years that I have been shooting raw that didn't need adjustment regardless of the camera or the editing application. For me, LR and as needed Photoshop provide what I need to make high quality photographs with the luminance, hues and saturation values I want for the photo at hand. There are areas for improvement in LR I'm aware of that haven't been addressed in this thread, but they are OT relative to the question the OP raised.
I know there are other applications out there with which one can do likewise, perhaps some more easily than others, but that is a different question.
I agree, although getting the Raw conversion 'right' without the need to iterate between controls in order to remove errors that are introduced by other tools, and vice versa, is a real time saver. For a certain project, I've lately been shooting and editing something like 5000 to 6000 images, and postprocessing them for publication. I can tell you, every minute saved without compromising output quality, is a huge benefit.
And by the way, this is not a new topic; the contrast/saturation linkage issue has a pedigree going well back in time; people agreed to disagree back then and this will probably continue to be the case indefinitely. With this, I think I have put in about the amount of time I can give to this thread. La Lutta Continua (probably without me)!:-)
Then why doesn't Adobe address the issue, one might ask. Competitors have.
To help understand the issue, in a non-mathematical way, I've attached 2 TIFF files in a ZIP archive. They are in ProPhoto RGB colorspace. The file named "Colorshift_100vs040.tif" has three gradients, one channel of each is running linearly in 32 steps from dark to light. The other channels desaturate the main channel by adding 40% of their color. You can check by dividing the relevant channel value by the channel value that desaturates the main channel. Rounding to integers aside, you should get 40% response.
Now add, for clarity sake (not that you'd be likely to use that much in practice) 100 Contrast, and read the response ratio's again (I've added a version in the ZIP file). They will vary above extreme shadows which are off the chart but limited also by low value precision from say 21% to 26 % instead of 40%, meaning that there is less desaturation, which boosts the saturation to unacceptably extreme deviations from their baseline (which now has an S-curve). Differences of 1% or more are already visible in a direct comparison.
Cheers,
Bart
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Bart, thanks, but my whole conceptual problem with this discussion is the notion of somehow "getting the raw conversion right" in some mostly automated manner. I agree with you that minimizing processing steps needed to produce a photo that is "right" in the mind's eye (because it is always so), would be desirable, especially in a mass production context. The problem for an application developer is that this is for the most part subjective and varies from photo to photo; the artistic side of this is that we actually do "make" the photo we imagined from the scene we captured. So they make judgments in designing these algorithms about what they think will satisfy most of the people by coming closest to finish earliest most of the time. But they know they will never satisfy all the people all the time.
To think back about how old this dilemma is, I remember back in the 1950s discussions I had with friends from Central Europe about the differences between Kodachrome and Agfachrome or Kodacolor and Agfacolor. The Kodak products produced kind of contrasty, saturated results while the Agfa products produced flatter, less saturated results. Which was better? Essentially it depended whether you came from North America or Central Europe, apart from dissidents like me who actually liked Agfacolor - perhaps I spent too much time in Central Europe. :-) Anyhow, you get the point.
Now fast forward to 2016 "a few decades" later and here I am using LR to convert my raw files. I would say, that even with PV 2012 which produces more contrast out of the box than the previous PVs did, more often than not I find myself INCREASING contrast AND INCREASING Vibrance, because I import them with everything "zeroed and linear" so-called (which under the hood it really isn't). I do this on purpose so that I can dial in my own decisions without needing to first undo other peoples' decisions. So I suppose, the introspection of my own practice and findings going back years now on a great many photos tells me that this is not an issue I should be concerned about. And if I feel a contrast move is adding a bit too much saturation, it takes a couple of seconds to damp it down a bit. Even if I multiply that by X operations in an evening, I'm not losing sleep over it.
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One can argue that different methods produce different results and sometimes some results are better than other results depending on the images and what is needed to adjustment. But to argue one method is antique and "modern" methods are better (presumably because they are newer) is pretty naive and is letting a bit of an anti "something" to show through...PS/ACR/LR do things a certain way...if you like the results, keep learning how to use them better.
Hi Jeff,
I find that (learning how to use better, when it's wrong to begin with) a very unproductive approach, which avoids any chance of improvement of something that (according to many) does not work well at all. You seem to argue that when something (sort of) worked in the past, that newer insights will not produce better results, without even doing an honest verification of that hypothesis. I could reverse the argument and claim that it is that attitude that is pretty naive.
If you don't like the results Bart, feel free to use something else.
I do, but should I therefore stop trying to educate people about the way that their favorite applications could be improved? If they are unaware, will they ask for better tools? Or are you suggesting that users of an application should not ask for more than they get handed out, and act more like sheeple.
But calling somebody a fanboy is really kinda juvenile in any reasonable debate or discussion.
You are missing the point.
The Germans have a nice saying that pretty much sums it up for me: "Was sich liebt, das neckt sich". An English version could be something like: "the quarrel of lovers is the renewal of love".
It is because I care about Photoshop as my main image processing tool, that I am critical about it's deficiencies. That is something that fanboys cannot understand, hence I'll let those whom the shoe fits wear it.
You have yet to prove your point regardless of the hand waving you've been doing :~)
I'll give it another try, although a true fanboy will not be convinced by any reasonable argument (regardless of the presentation), it's behavior that's also called "cognitive dissonance". I'm an optimist, so I believe there is hope for those who are willing, therefore another attempt.
Attached there is a ZIP archive with 3 images.
a) One image as downloaded from BabelColor.com is the source of this experiment, it's called "ColorChecker_sRGB_from_Avg_16bit.tif". I took that image because it is easily displayed even on displays with modest capabilities, and it has several common/relevant colors for investigation, like skin tones, and some tones we can find in nature/landscapes. There are other colors not in the chart that are more critical, like those of flowers. So the effects demonstrated in the ColorChecker, can become even more visible in other subject matter.
b) An image called "ColorChecker_sRGB_from_Avg_16bit_ACRContrast+000_ProPhotoRGB.tif" is a simple import of that file in ACR, and exported as a ProPhoto RGB version of the file, the default working space of many users. No changes were made, no sharpening, no noise reduction, nothing. This will serve as the baseline to compare against. So any hidden changes to the file data would be present in the file, just to make sure we will compare apples to apples.
c) An image called "ColorChecker_sRGB_from_Avg_16bit_ACRContrast+100_ProPhotoRGB.tif" after only applying a +100 Contrast adjustment, nothing else was changed.
The images 'b' and 'c' were saved without any further alterations as they came out of Photoshop's ACR plugin, so they are as you could create them from the original image 'a' yourself, but I've spared you the exercise and thus it is also possible for non-Photoshop users to follow the proceedings or for those who do not want to fiddle with their settings and are afraid to change their current setup.
Now, let's have a look at e.g. the first (Row 1, Column 1) , "Dark skin" patch.
After the ACR conversion to ProPhotoRGB, image 'b' now reads in 8-bit colors:
RGB=[81, 68, 55], Lab=[38, 13, 14], HSB=[30°, 33%, 32%]
After the ACR Contrast boost and conversion to ProPhotoRGB, image 'c' now reads in 8-bit colors:
RGB=[79, 60, 40], Lab=[36, 19, 23], HSB=[31°, 50%, 31%]
Because it is a darkish color, the contrast adjustment made it darker still, as intended. But it also increased the saturation, just look at the coordinates in Lab, _a and especially the _b values increased significantly, or the HSB coordinates which even show a slight Hue change, a significant Saturation increase by 17% (whereas a 1% difference is usually visible in a direct comparison).
I know that the +100 Contrast adjustment in ACR is extreme, but that's just to make it easier to see what also happens at lower settings, albeit obviously with lower amounts.
Let's have a look at e.g. the second (Row 1, Column 2) , "Light skin" patch.
After the ACR conversion to ProPhotoRGB, image 'b' now reads in 8-bit colors:
RGB=[157, 136, 113], Lab=[66, 16, 18], HSB=[30°, 28%, 62%]
After the ACR Contrast boost and conversion to ProPhotoRGB, image 'c' now reads in 8-bit colors:
RGB=[191, 162, 133], Lab=[75, 20, 22], HSB=[31°, 31%, 75%]
Again, we not only see an intended change in brightness, but also an additional increase in Saturation, and it's expected when we change brightness channels with the same amount in the R/G/B channels in RGB space instead of doing it in the correct manner. Because Luma and Chroma are not decoupled in RGB colorspace, a change to one will affect the other in the wrong way.
One more color patch, relevant to landscape photographers, the third (Row 1, Column 3) , "Blue Sky" patch.
After the ACR conversion to ProPhotoRGB, image 'b' now reads in 8-bit colors:
RGB=[95, 102, 134], Lab=[50, -4, -22], HSB=[230°, 29%, 53%]
After the ACR Contrast boost and conversion to ProPhotoRGB, image 'c' now reads in 8-bit colors:
RGB=[104, 114, 163], Lab=[55, -6, -31], HSB=[229°, 36%, 64%]
The results speak for themselves, Saturation is again exaggerated compared to the intended change in Brightness.
The amount of the Saturation change will vary a lot, especially with medium and lower Brightnesses and with already rather Saturated colors (one or two channels with a low contribution) like those in the second row of the Colorchecker. I'll leave the analysis of those for the readers, but if such colors are part of the scene, they will suffer even more than the more neutral colors.
I could continue, but I assume that the pattern is clear by now.
Now, the naysayers might argue that that exaggeration of Saturation with increased contrast is more pleasing, well I disagree. There is a reason why many others raise questions about the saturation changes, like the OP, or programmers who devise perceptually better methods that produce more natural/pleasing results.
Well arguing about taste is pretty useless, but maybe we can quickly look at how nature intended things to be.
Again, take the first patch, "Dark skin": RGB=[81, 68, 55], Lab=[38, 13, 14], HSB=[30°, 33%, 32%]
When we plug the RGB values into Bruce Lindbloom's excellent CIE Color calculator (http://brucelindbloom.com/ColorCalculator.html) (see attachment), and change the RGB model to ProPhoto RGB, then the Lab values come out at the exact same values (after rounding to integer numbers). So we've verified that Photoshop uses the same (correct) color coordinate calculations.
When we now change the luminance 'Y' value in xyY coordinates from 0.102501 to say 0.090082, we'll get about the same drop in the L channel as ACR produced ( Lab=[38, 13, 14] -> Lab=[36, 19, 23] ), L=38 becomes L=36. However, instead of boosting Saturation like ACR does, according to Bruce's calculator the Saturation should have been reduced a bit (in line with the reduced luminance), the color should have become RGB=[75, 63, 51], Lab=[36, 12, 13] to look as nature intended it.
So we may conclude that ACR produces Saturation values that are not how natural Contrast changes would affect color/saturation. Some find that acceptable, others like me don't. Even if it were true, after research results would be published for peer review, that people prefer those unnatural color changes (just like some like overprocessed HDR images), it would be much better if that was left to the users to begin with.
Because first oversaturating, and then desaturating in a different way, will not be as accurate, nor will it be easy (due to how color vision works). We as humans are not that good at absolute color (due to preconditioning and changes due to ambient luminance levels), but better at color differences (almost simultaneous observation). When we are preconditioned with an oversaturated version, it becomes harder to restore to natural color. In Photoediting, it is usually best to start with a neutral basis (only adjusting exposure and contrast), and then alter colorbalance / local color / Saturation to better match a creative intent.
Cheers,
Bart
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Well arguing about taste is pretty useless, but maybe we can quickly look at how nature intended things to be.
Congratulations Bart, you've now taken your argument down the road that "NATURE" intended contrast adjustments without saturation adjustments. Care to point that out in the "Rules Of Nature" booklet?
Yes, your convoluted and complicated argument and proofs prove that ACR increases contrast and saturation–pretty sure we agree on that, right? The only point of contention is that Thomas sees it correct to increase saturation when increasing contrast while you consider that an act against nature...do I have that right?
Thomas said he decided to increase saturation when increasing contrast because that's what happens to film when you push process, you increase contrast AND saturation. Thomas was a film photographer well before he wrote Photoshop so when he designed his tools for digital imaging he decided to make the digital emulate the analog film appearance.
One can ague that was a mistake and an abomination of nature but somehow it just does not rise to that level with me.
Use whatever tool floats your boat but unless legions of users line up in protest against ACR's saturation increase when increasing contrast (by +100) I'll bet Thomas will STILL keep the saturation and contrast tied together because he honestly thinks it's the right thing to do. If that makes ma a fan boy...I'll wear those shoes–they are comfortable and make me look marvelous!
BTW, I did download your files and played...actually C1 8.x contrast increase sure looks about the same as ACR. I haven't built out a file and read the samples yet. I'll try to get to it, but I do kinda have a life outside of LuLa ya know...Have a nice Sunday. I'm gonna go see Finding Dora so I don't have to worry about Camera Raw screwing up my images for a couple of hours. That will be a relief!!!
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Congratulations Bart, you've now taken your argument down the road that "NATURE" intended contrast adjustments without saturation adjustments. Care to point that out in the "Rules Of Nature" booklet?
Yes, your convoluted and complicated argument and proofs prove that ACR increases contrast and saturation–pretty sure we agree on that, right? The only point of contention is that Thomas sees it correct to increase saturation when increasing contrast while you consider that an act against nature...do I have that right?
Hi Jeff,
Unnatural looking edits, not an act against nature. I'm beginning to see why you talked about a juvenile response earlier, it may have something to do with the mindset of the beholder.
Thomas said he decided to increase saturation when increasing contrast because that's what happens to film when you push process, you increase contrast AND saturation. Thomas was a film photographer well before he wrote Photoshop so when he designed his tools for digital imaging he decided to make the digital emulate the analog film appearance.
One can ague that was a mistake and an abomination of nature but somehow it just does not rise to that level with me.
While that may have influenced his mindset and the resulting decision to go with that choice at the time, there is no need to persist with that if new insights show that it's demonstrably producing issues with digital image processing. Had he made the decision today, he probably would have chosen a different approach. Nothing wrong with that. We all learn as we go, and hindsight has 20/20 vision.
However, principles become dogmas when people stop (re)thinking, that can become dangerous. Other software makers are rethinking and adopting the more natural way of contrast adjustment.
BTW, I did download your files and played...actually C1 8.x contrast increase sure looks about the same as ACR.
Yes, they fixed that in C1 version 9. Now it produces much more natural results, works great and it's a real time saver.
BTW Also C1 changes saturation when contrast is adjusted, but it looks much more natural. It is hard to do a direct comparison, because of the difference in the color engines, but I'll try to find something based on a Raw file that demonstrates the differences.
I haven't built out a file and read the samples yet. I'll try to get to it, but I do kinda have a life outside of LuLa ya know...Have a nice Sunday. I'm gonna go see Finding Dora so I don't have to worry about Camera Raw screwing up my images for a couple of hours. That will be a relief!!!
Have a nice Sunday. I've heard that "Finding Dory" is considered to be a great movie, already scoring an 8.1 out of 10 on IMDB. Have fun.
Cheers,
Bart
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While that may have influenced his mindset and the resulting decision to go with that choice at the time, there is no need to persist with that if new insights show that it's demonstrably producing issues with digital image processing. Had he made the decision today, he probably would have chosen a different approach. Nothing wrong with that. We all learn as we go, and hindsight has 20/20 vision.
................
Cheers,
Bart
Bart, I think there may be a risk here that you are super-imposing matters of preference on matters of intellectual capability, and that could be a mistake, if I may say so. Firstly, I should remind - this is a very old debate. I was an active participant in it nine years ago in several fora and I can assure you that a number of us have examined this issue comprehensively. Back then we found no fundamental flaws with ACR's processing capabilities in the areas of greatest concern, and that was even before all the improvements that have been made since.
Secondly, it would be a grievous error to assume that the Adobe programming team doesn't have the smarts and the objectivity to take stock of what they are doing, take stock of what competitors are doing, take stock of what suits the market and react accordingly; and even if the programmers themselves didn't do this actively, you can bet your bottom Euro that their QC and Management overseers would be doing so; but these are highly professional folks with total awareness. In LR, for example, they have been through three process versions already. In each one of them they have tweaked the performance of the various tools, most notably in PV2012. At any point along that juncture if they saw the need or the desirability to change the rendering along the lines you suggest, I have no doubt whatsoever they would have done it, and they would have explained to the clientele why they did what they did, and provided an option for those who don't like it. So based on what I know of them, you cannot dismiss this team as dogmatic people who have stopped thinking. And as such, you cannot dismiss the possibility that just maybe you and others who share your perspective don't have a monopoly on the "right" answers in this area, because maybe in the final analysis there are no "right" answers - it is all a matter of the logic and preferences of one set of programmers and users versus another, both having their own legitimacy.
Well, yes, a beautiful Sunday afternoon here in Toronto as well, so good to cut the arguing and enjoy the sunshine!
Cheers.
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While that may have influenced his mindset and the resulting decision to go with that choice at the time, there is no need to persist with that if new insights show that it's demonstrably producing issues with digital image processing.
...in your opinion. So far, your arguments fall back to numbers and not appearance. The video you alluded to failed to make the appearance argument. So far, you've failed to provide much in the way of evidence of real world editing failing in ACR while being demonstrably better in some other app. And different is not better, it's just different. Go any images where ACR fails and some other app shines?
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Unnatural looking edits, not an act against nature.
IMHO, the current behavior you're against produces far more natural looking edits to the alternative.
And of course there are the tens of thousands of ACR/LR users and their massive number of processed images that highly suggest there's not a problem, and that these thousands of customers have no issue whatsoever with how Thomas handled this behavior.
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IMHO, the current behavior you're against produces far more natural looking edits to the alternative.
But then Eric Chan’s comment (which you kindly provided in post #4) clearly suggests that there is room for improvement.
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Eric Chan wrote:
Thomas and I separately explored the side effects and implications of various tone curve implementations (he in the early days of Camera Raw, I when working on color profiles in 2008 and again in 2010). I learned a few things along the way.
One is that contrast and saturation are often correlated in the real world, which is why an increase in contrast often (though not always) works well with an increase in saturation. Clarity is an example of a contrast control that doesn’t obey this: it allows you to increase/decrease (local) contrast while preserving saturation. If you’ve ever tried a strong negative Clarity adjustment on a colorful image, the result looks a bit odd. Similarly, if you’ve taken a rather pale image and added strong positive Clarity but without punching up the Saturation/Vibrance controls, the result also tends to be artificial. So we’ve not been entirely consistent in how we’ve dealt with saturation side effects in our contrast controls, but I’d probably give the nod to Thomas’s design (saturation side effect).
A second lesson is that the choice of color space makes a big difference to the result. As Jeff, Andrew, and others have widely documented, we use ProPhoto as our choice of RGB primaries, which is a good thing in many cases. For saturation side effects in curves, though, there are some issues. In particular, due to the position of the blue ProPhoto primary, this means our current tone curve tends to have much stronger blue saturation side effects than in other hues. In particular, if you have a typical S curve or just increase the Contrast control, darker blue tones (such as first column, third row of a standard ColorChecker, or deep blues in water reflections) tend to get overly saturated, and lighter blue tones (such as skies) tend to become overly desaturated. There are ways to get the saturation side effects to be more perceptually uniform, and I’m investigating those for the future (would likely require a process version bump, though).
A third lesson is that our current color control set within the ACR/LR UI isn’t really good (yet) for doing 3D color edits. This is because one cannot fully control how hue and saturation are affected as a function of lightness (or brightness, or luminance, or whatever term you want to use). For example, when you use HSL controls to change the Orange hues, that changes them for all orange hues, light and dark. You can’t change them separately for light vs dark hues. It is possible, of course, to use per-channel RGB curves to bring back Photoshop-style hue twists in tone curves, but even though you don’t have full control over how those twists behave.
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But then Eric Chan’s comment (which you kindly provided in post #4) clearly suggests that there is room for improvement.
There's always room for improvement like providing the user both options. Assuming again:
1. There's an outcry from users that they must have it (there isn't).
2. It's not going to complicate the product for the gain of a tiny few users.
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But then Eric Chan’s comment (which you kindly provided in post #4) clearly suggests that there is room for improvement.
In particular, if you have a typical S curve or just increase the Contrast control, darker blue tones (such as first column, third row of a standard ColorChecker, or deep blues in water reflections) tend to get overly saturated, and lighter blue tones (such as skies) tend to become overly desaturated. There are ways to get the saturation side effects to be more perceptually uniform, and I’m investigating those for the future (would likely require a process version bump, though).
Simple fix for darker saturated blues requiring no process version bump IMO. I do this all the time, no complaints. Adjustment brush works just as good. I can quickly add color to change the blue using its color picker. This A/B sample below was done in ACR 6.7 which means this was fixable a long time ago.
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...in your opinion. So far, your arguments fall back to numbers and not appearance. The video you alluded to failed to make the appearance argument. So far, you've failed to provide much in the way of evidence of real world editing failing in ACR while being demonstrably better in some other app. And different is not better, it's just different. Go any images where ACR fails and some other app shines?
Hi Jeff,
I've attached some image (!) samples for you, that show the difference in handling of Contrast changes. Also note that it's not only the different look (which of course can be further processed to look more similar), but it is also about the workflow which IMHO allows to better achieve a certain creative intent, because we do not need to compensate color saturation issues caused by Contrast adjustments as much. We can simply adjust Contrast if we want to adjust Contrast, and adjust Saturation if we want to adjust Saturation, and even the order in which we do that is not important.
It is difficult to create an exact one-on-one comparison between different applications, due to differences in camera profiles and color engines. So the images will already look different, but I've tried to make the baseline images look somewhat similar.
First the before and after images of Capture One Pro version 9. When I can find some more time, I'll add Lightroom or ACR results in a followup post.
I've sampled one spot in the sky, and noted the RGB, Lab, and HSB coordinates of the resulting JPEGs, first before contrast boost and then after a contrast boost of +50. That's the maximum of the scale, which probably is a different scale than ACR/LR anyway.
** Blue Sky **
RGB = [139, 165, 192] --> RGB = [161, 194, 229]
Lab = [66, -5, -17] --> Lab = [77, -5, -21]
HSB = [211°, 28%, 75%] --> HSB = [211°, 30%, 90%]
The contrast curve (probably) has a different shape in Capture One, so let's not focus on the absolute values, but the relative change. Easiest for most people is maybe to compare the HSB (Hue, Saturation, Brightness) coordinates. Hue is not changed after the Contrast boost. We can see a significant increase of the Brightness, as expected for a boost in contrast of brighter colors in a larger scene. Saturation only scores a modest increase of 2%, despite the Brightness boost by 15%.
Of course highlight detail gets severely compressed by such an extreme contrast boost, so one would usually correct that with the other controls but that's not what we're investigating in this thread (nor would I use such an extreme contrast boost in normal practice). I'll repeat, the extreme adjustments are done to see if and how the algorithms fall apart, because small changes will even look acceptable with a crappy algorithm and that would not tell us much.
The other crops from the same scene are of two different grass tones, one dark shaded tone, and one transilluminated more yellow tone.
** Grass darker **
RGB = [64, 83, 1] --> RGB = [36, 52, 3]
Lab = [33, -16, 39] --> Lab = [19, -13, 26]
HSB = [74°, 99%, 33%] --> HSB = [80°, 94%, 20%]
** Grass lighter **
RGB = [144, 174, 1] --> RGB = [174, 217, 6]
Lab = [67, -25, 67] --> Lab = [81, -31, 78]
HSB = [70°, 99%, 68%] --> HSB = [72°, 97%, 85%]
Here we see a change in Hue, more for the darker grass than for the lighter grass. The darker Green gets darker, and the lighter Green gets lighter, as expected for a contrast boost. We see that both Greens get Desaturated (!), the dark patch more (to avoid oversaturation due to the already low blue channel contribution).
When I have a bit more time I'll do a similar run with Lightroom, but people can of course already have a look at how their own images handle extreme contrast boosts of sky blue and grass/foliage.
Cheers,
Bart
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Bart, your image samples don't prove anything. Good grief. Why would someone apply +50 contrast to a cloud image whose overall luminance is above middle gray. And no one would just do the same with the greenery image.
I take it you want the simplest turnkey twiddle knob to do the same across all images without any sense of what the real scene looked like as a starting point. Those samples are unrealistically predetermined to fail adding a contrast boost.
Go back and try again.
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Bart, your image samples don't prove anything. Good grief. Why would someone apply +50 contrast to a cloud image whose overall luminance is above middle gray. And no one would just do the same with the greenery image.
Tim,
Reading comprehension appears to be harder for some than I thought. I already explained, several times, that small changes will lead to small issues, so IF ONE WANTS TO LEARN something about the robustness of the algorithms used, exaggeration helps. If extreme corrections do not lead to the kind of issues that this thread is about, then lesser adjustments will do even better.
Cheers,
Bart
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Bart, your image samples don't prove anything.
That's pretty harsh Tim. I don't agree ;) . Bart clearly demonstrated that a raw file will appear different depending on the raw processor. Maybe that's a big idea/concept for some, for the rest of us, not at all. Otherwise, I don't think he proved anything (so we're then in violent agreement!).
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Tim,
Reading comprehension appears to be harder for some than I thought. I already explained, several times, that small changes will lead to small issues, so IF ONE WANTS TO LEARN something about the robustness of the algorithms used, exaggeration helps. If extreme corrections do not lead to the kind of issues that this thread is about, then lesser adjustments will do even better.
Cheers,
Bart
Not reading comprehension, Bart. Just lack of patience and time to read that long complicated outline of yours. So I had to assume going by the title of this thread that you were demonstrating contrast induced saturation. I still wouldn't know what you said even if I did read all of it because it's just too damn long and complicated to focus on. I read your other long posts and I still kept reading the same obvious stuff I already know. I just assumed you were pointing out more of the obvious.
The time it would take to read all that and understand it, I just improved the look of your grass/concrete step image without any saturation issues in ACR 6.7.
I still don't see with your points being made how you're making editing images any easier and less complicated. I still make better looking images without all that analysis. Why can't you?
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We see that both Greens get Desaturated (!), the dark patch more (to avoid oversaturation due to the already low blue channel contribution).
Well if one of us has reading comprehension issues then the other has color perception issues. I'm not seeing that green get desaturated, Bart. I see more saturated green compared to the original and since you didn't white balance the image (concrete sidewalks aren't greenish yellow in bright sunlight) you've actually compounded the appearance of over saturated greens with the added contrast.
White balance plays hand in hand with saturation appearance and the amount of its increase due to increased contrast.
Could you post an image that is finished and looks good to you because you edited with software that doesn't increase saturation when adding contrast? Post a before and after. I would once like to see an image that looks good with this technique.
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Could you post an image that is finished and looks good to you because you edited with software that doesn't increase saturation when adding contrast? Post a before and after. I would once like to see an image that looks good with this technique.
Good question! Without being blasphemous, it could be a Frosty Friday in Hell before one like that occurs, but one must always ask just in case.........."never say never" :-)
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Well if one of us has reading comprehension issues then the other has color perception issues. I'm not seeing that green get desaturated, Bart. I see more saturated green compared to the original ...
Tim, when the S (is Saturation) in HSB coordinates goes from 99% to 94% for darker grass (HSB = [74°, 99%, 33%] --> HSB = [80°, 94%, 20%]), and for lighter grass from 99% to 97% (HSB = [70°, 99%, 68%] --> HSB = [72°, 97%, 85%]), then saturation has decreased.
What you have just demonstrated is that we cannot rely on our eyes to estimate absolute colors/values, and even in comparison we can miss the mark. What did change was the Contrast and thus the Brightness depending where on the various brightnesses land on the contrast curve. When we change the Brightness of a Color, even if we would keep the Saturation the same, it seems to have changed. That's how human vision works. The last thing we need when changing Contrast, is another Saturation boost, which we would then have to reduce by another editing effort (which is quite doable as you've shown in your earlier example, but requires adding another edit step).
This thread is not about if we can correct Saturation boosts that result from Contrast changes, but why should we need to do that if the software could largely avoid the excessive Saturation boost (or reduction) to begin with.
... and since you didn't white balance the image (concrete sidewalks aren't greenish yellow in bright sunlight) you've actually compounded the appearance of over saturated greens with the added contrast.
Wrong again. The concrete was not pure grey*, and the White-balancing was exactly the same as for the white of the clouds. Had I color-balanced on the concrete, then the clouds would have been too blue. I've attached an HDR rendering of the scene that I've posted for another purpose in another thread before.
*) Exposure brackets for that HDRI were used for the crops I posted here and they are of one and the same scene, and Art object (a WW II bunker, number 599 (http://www.raaaf.nl/en/projects/7_bunker_599), from 1940 that was sawed in half).
White balance goes hand in hand with the appearance of Saturation and the amount of its perceived increase due to increased contrast.
Could you post an image that is finished and looks good to you because you edited with software that doesn't increase saturation when adding contrast? Post a before and after. I would once like to see an image that looks good with this technique.
For the purpose of demonstration I'll humor you. Attached are a before, and an after +25 Contrast adjustment image, made in Capture One Pro version 9.2.0. Also, it is not a technique, but a single (more intelligent) Contrast slider control.
Again, there is generally only a very modest change in Saturation, and virtually no color Hue shift, compared to the significant change in contrast (higher for brights, lower for darks). And because our eyes can fool us, I've again added some color sample readouts, taken from the images before final conversion, in this case from AdobeRGB to sRGB, for display.
* Sky *
RGB = [132, 141, 175] --> [144, 154, 193]
Lab = [59, 1, -20] --> [64, 1, -23]
HSB = [227°, 24%, 69%] --> [227°, 25%, 76%]
* Grass dark *
RGB = [61, 62, 38] --> [47, 47, 28]
Lab = [24, -4, 17] --> [17, -4, 15]
HSB = [61°, 38%, 24%] --> [61°, 41%, 19%]
* Building *
RGB = [158, 118, 100] --> [174, 126, 105]
Lab = [55, 20, 20] --> [59, 24, 23]
HSB = [19°, 37%, 62%] --> [18°, 40%, 68%]
Now you'll probably say that the contrast has become too high, or find an other excuse to reject the image quality (like the sky being a tad too magenta, which might be true but that was the same for both images), but I did not have to adjust the Saturation like you had to do in the example that you posted earlier. I could have, and would only have needed a very small amount to achieve that, without again changing the contrast as a result, causing to revisit that, which in turn .....
The question that this thread is about is simple, when we choose to change the contrast, then why do we also need to adjust the Saturation back to where it already was???
Cheers,
Bart
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The question that this thread is about is simple, when we choose to change the contrast, then why do we also need to adjust the Saturation back to where it already was???
The answer is equally simple. Because most of the time, it LOOKS better. And if it doesn't, there's a fix (adjustment) for that.
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The answer is equally simple. Because most of the time, it LOOKS better. And if it doesn't, there's a fix (adjustment) for that.
Hi Andrew,
It sounds like you like to dance. Two steps forward, one step back, to get where you wanted to be in the first place.
Seems like a waste of time to me, unless you like to dance instead of saving the time for other things (aka productivity and higher output quality).
Cheers,
Bart
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It sounds like you like to dance. Two steps forward, one step back, to get where you wanted to be in the first place.
Incorrect on both points. Again, most, if not all the time for myself and perhaps tens of thousands of Adobe users, the default behavior is what looks better! Was Jeff's description of what Thomas found and thus coded unclear to you? Seems so. Like any default position, there are times it's not appropriate and IF so, there's an easy fix. Meanwhile, the behavior you propose, that doesn't LOOK as good as what you are arguing against, would require more dancing, steps, more of the time.
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Incorrect on both points.
Maybe you should try it then. Dancing can be good exercise and it can be fun (depending on the company one keeps). But it leads you nowhere, essentially just going round in circles. In my younger years I received a gold star recognition for my Ballroom dancing skills.
Again, most, if not all the time for myself and perhaps tens of thousands of Adobe users, the default behavior is what looks better!
Well, in that case I'd hurry and convince Eric Chan, before he improves the Raw conversion engine...
Cheers,
Bart
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Maybe you should try it then. Dancing can be good exercise and it can be fun (depending on the company one keeps).
As someone who walks/runs over 5 miles a day, I'm good. Just as I and many, many others are more than good with the current Adobe behavior that again, was produced BY design because it LOOKS better 9+ times out of ten. And when it doesn't, easy to adjust.
Well, in that case I'd hurry and convince Eric Chan, before he improves the Raw conversion engine...
I hope he and Thomas continue to do so and expect they both will. Meanwhile, you're not getting much traction around these parts with your concepts of Contrast and Saturation but hey, it's your time to waste.
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Recommended reading: Tone curves and camera profiles (http://www.ludd.luth.se/~torger/dcamprof.html#tone_curves)
by Anders Torger
quote: >>So then all is good with the tone curves applied by typical raw converters? No. In fact if we’re into a neutral and realistic starting point it’s not good at all. Most converters apply a pure RGB curve which has little to do with perceptual accuracy. Lightroom and many DNG raw converters apply a slightly different RGB curve that reduces hue shift problems (HSV hue is kept constant), but it’s still in most situations almost identical in look to a pure RGB curve. It varies between converters in which RGB space this curve is applied, which also affects the result. In Lightroom/DNG it’s always applied in the huge linear ProPhoto color space, while in many ICC raw converters it’s applied in a smaller color space.
Let’s start with the RGB tone curve problems. It will increase saturation more than is reasonable to compensate for Stevens and Hunt effects, so you get a saturated look. You might like that, but it’s not realistic. Another problem is that for highly saturated colors one or more channels may reach into the compressed sections in highlights or shadows and that leads to a non-linear change of color, that is you get a hue shift. Typically the desired lightening and desaturation effect (transition into clipping) masks the hue shift so it’s not a huge problem, but it’s there.
Then there is the color space problem. If the RGB tone curve is applied in a large color space such as one with ProPhoto primaries (like in the DNG case) one or more channels can be pushed outside the output color space (typically sRGB or AdobeRGB) so we get clipping and thus a quite large hue shift. Some raw converters partially repair this through gamut mapping (Lightroom does), but still there may be a residual hue shift.
To battle the various RGB tone curve issues bundled profiles typically have various subjective adjustments to counter curve issues. For example the profile may desaturate high saturation reds to avoid color space clipping. Naturally this means that the same profile used with a linear curve will produce too little saturation in the reds. That is a profile must be specifically designed for the intended curve.
I think this is bad design. In fact one could argue that staying with RGB curves (and similar) has inhibited the development of good profiling tools and makes it unnecessarily hard to get natural colors in our photos.
It doesn’t have to be this way, the RGB tone curve is legacy from the 1990s when its low computational cost was one of the reasons to use it. It can also be seen as a nostalgic connection to film photography. In the film days the film had to produce the subjective look too, so exaggerated contrast and saturation were desirable properties. This thinking has been kept in most raw converters today despite that we have all possibilities to start from a neutral look and design our own on top rather than relying on bundled looks. The RGB tone curve produces a saturated look that many like to have in their end result, but as said it still doesn’t work well for profiles that aren’t specifically adapted for it.
Using a DCamProf neutral linear profile and applying and RGB tone curve will produce a garish look. As we will see, the solution to this problem is to use DCamProf’s built-in neutral tone reproduction operator.<<.
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Meanwhile, you're not getting much traction around these parts with your concepts of Contrast and Saturation but hey, it's your time to waste.
Actually its a really interesting post, for the views and understanding of whats "under the hood" and what other image characteristics are affected by alterations in contrast (which I think most of us manipulate on most images) and how that differs with different raw developers (and between their process versions). Of course preference is subjective (thankfully), but the suggestion that what is best is what was first done (eg by ACR, lightroom and C1 up to version 8), or because most people are happy with what they are used to (a proxy being user numbers) seems a bit stuck in the mud. Thanks Bart for as always providing detailed explanation (often over my head, but that's my problem), and examples to illustrate those discussions. Please dont consider doing so a waste of time as suggested.
Cheers
Brandon
PS less interesting is reading how "short" some are in their comments (this thread and others)
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Recommended reading: Tone curves and camera profiles (http://www.ludd.luth.se/~torger/dcamprof.html#tone_curves)
by Anders Torger
Not saying that Anders has an agenda but he clearly doesn't like the default tone curve in DNG Profiles (something I'm surprised that Bart isn't jumping up and down and yelling about) but I'm not sure that recommended reading is 100% on point. Anders wanted to create a DNG profile that didn't apply a tone curve by default. There are ways around that by using DNG Profile Editor and defeating the the builtin tone curve.
Course then you have the problem of either living with ACR's toning controls and understand there are a LOT of tone controls above and beyond Contrast-which truth be told I rarely if ever use or process the raw image with a linear tone curve and manipulate further in Photoshop or your other non-Adobe manipulator of choice.
But I think it would be better to stick to the "ACR's Contrast control suck" argument.
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It doesn’t have to be this way, the RGB tone curve is legacy from the 1990s when its low computational cost was one of the reasons to use it. It can also be seen as a nostalgic connection to film photography. In the film days the film had to produce the subjective look too, so exaggerated contrast and saturation were desirable properties. This thinking has been kept in most raw converters today despite that we have all possibilities to start from a neutral look and design our own on top rather than relying on bundled looks. The RGB tone curve produces a saturated look that many like to have in their end result, but as said it still doesn’t work well for profiles that aren’t specifically adapted for it.
[/quote]
Thanks this extract is helpful
Regards
Brandon
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... and since you didn't white balance the image (concrete sidewalks aren't greenish yellow in bright sunlight) you've actually compounded the appearance of over saturated greens with the added contrast.
Wrong again. The concrete was not pure grey*, and the White-balancing was exactly the same as for the white of the clouds. Had I color-balanced on the concrete, then the clouds would have been too blue.
That's not what I'm seeing. How do you explain the two hues of concrete even the Lab numbers bare out in the attached screengrab?
That's a hue shift. Was that created by adding contrast or did you not set the WB according to the numbers because I'm sure you don't rely on your eyesight to judge color.
The A/B demo of the glass/brick building really shows what this saturation/contrast detachment looks like. I see your point, now.
But do you really think that looks good? Or do you like to make images that follow colorimetrically accurate to scene renderings?
Those images look very accurate to reality, but a boring ashen colored reality. They remind me of technical images used in instruction manuals from NASA or the images hung on the inside walls of my Dad's oilfield supervisor trailer promoting new drill bit design and frac machinery.
I would not want to make a print of those colors.
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I use both ACR/C1 and do prefer the contrast behavior in C1 v9.
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I not sure why but if in Phocus you increase the Clarity it has a much different effect than LR better to my taste it won't halo on you even at 100%!
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The A/B demo of the glass/brick building really shows what this saturation/contrast detachment looks like. I see your point, now.
But do you really think that looks good? Or do you like to make images that follow colorimetrically accurate to scene renderings?
Tim, that is actually a good question for the topic of this thread. Let me put it this way: Almost all images we produce (unless they are reproductions, converted with a specially made linear camera profile) are not colorimetrically accurate. On top of that nobody stops us from adding our own creative touch, but at least we can start from a relatively predictable starting point.
That makes it easier to see the differences. If I add contrast, or reduce it, because the subject benefits from that, I won't have to ask myself how much of the Saturation and resulting color I see is due to the subject and ambient lighting, and how much was from the contrast change. What I see is what came from the subject and lighting, and if I do not like it, I can change it knowing that if I later decide to modify contrast again, I won't have to worry about the saturation and color all over again, because it will not be significantly affected. IOW, it's a much more robust way of editing, more predictable.
I would not want to make a print of those colors.
No problem, you don't have to. Again, besides personal preferences and subjects, there are countless way that images can be rendered and they may look all fine in their own special way. The images that I posted were more a demonstration of the effect of Contrast changes. Surprising to some, it can change just that, Contrast, and still give an impression that Saturation was affected, which it hardly did.
But the thread is more about the distraction in the editing process, that Saturation changes when we actually wanted to change something else, Contrast.
Without that distraction, it's not too difficult to further tweak the image in a very predictable way. Some images are hard enough to get right, because nature already challenges our Camera response enough, like with the attached eagle-owl that has such saturated irises already that the captured blue channel is zero, or the already very saturated reds of the wild-water rafters. Any change I make to adjust the Contrast, will leave that Saturation mostly untouched.
Cheers,
Bart
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But the thread is more about the distraction in the editing process, that Saturation changes when we actually wanted to change something else, Contrast.
We (all) do? When someone speaks for everyone: warning Will Robinson, danger!
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We (all) do? When someone speaks for everyone: warning Will Robinson, danger!
Simple question Andrew,
If you change Contrast with the Contrast control, what is it in the image that you want to change?
And if you want to adjust the Saturation in an image, wouldn't it be logical to use the Saturation control for that? Just wondering, because you make it sound as if you don't want the controls to do what they should do, which puzzles me.
Cheers,
Bart
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I not sure why but if in Phocus you increase the Clarity it has a much different effect than LR better to my taste it won't halo on you even at 100%!
Hi,
Clarity can be implemented in various ways between applications. Unfortunately some produce halos, and some don't. How they let Clarity deal with Saturation could also depend on how they handle Contrast. So I'd suggest to use whichever application does best without unwanted side effects.
Cheers,
Bart
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Hi Bart, just wanted to say a huge thank you for your patience and level-headedness in explaining in great detail this issue of chroma shifting with contrast/RGB curves adjustments. Personally I've long known this behaviour with ACR/LR curves and it has irked me more than helped me. Often I can't completely/perfectly reverse the non-uniform saturation increase across the tone scale with the saturation or vibrancy sliders or even the HSL sliders, and even if I could, it's an annoying waste of time. In Photoshop of course we have the Luminosity Blend Mode which I prefer to use almost always with a RGB curves adjustment. These days I prefer Raw Therapee over Lightroom for all my raw image processing, which has several ways to adjust the tonality of an image without resulting in exaggerated chroma shifts. I'm glad about that. It's really jarring to read your civil and logical comments against some of the other more dismissive ones. Bart, you definitely have complete 'traction' with me.
Cheers,
Samuel
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Hi Bart, just wanted to say a huge thank you for your patience and level-headedness in explaining in great detail this issue of chroma shifting with contrast/RGB curves adjustments. Personally I've long known this behaviour with ACR/LR curves and it has irked me more than helped me. Often I can't completely/perfectly reverse the non-uniform saturation increase across the tone scale with the saturation or vibrancy sliders or even the HSL sliders, and even if I could, it's an annoying waste of time. In Photoshop of course we have the Luminosity Blend Mode which I prefer to use almost always with a RGB curves adjustment.
Hi Samuel,
I do the same if further contrast adjustments in Photoshop are needed (especially important if Black/Whitepoint is shifted in, because that also seriously affects Saturation). I somehow wish 'Luminosity' could be made sticky (even if only for the current session), instead of 'Normal' for the Curves adjustment layer, because it usually happens as a final tweak that is targeted for a specific output, and it then messes with the earlier Saturation settings. I suppose it's a residue from the time that color was heavily edited with a Curves control as well. Nowadays we usually do Color adjustments at Raw conversion time.
These days I prefer Raw Therapee over Lightroom for all my raw image processing, which has several ways to adjust the tonality of an image without resulting in exaggerated chroma shifts. I'm glad about that. It's really jarring to read your civil and logical comments against some of the other more dismissive ones. Bart, you definitely have complete 'traction' with me.
Thanks, although I'm not after traction, or likes, pats on the back, or other things people may come up with. Personally, as my signature line says, I'm constantly looking for new/better ways to do things, especially when the things 'that I got' before are not to my liking. If that leads to a new discovery that makes sense, or as in this case adds to a discussion, I like to share that for the benefit of others (who often in return also share some of their findings, a win win situation).
RawTherapee has a lot going for it, and it's also free. The main hurdle for most is the less polished user interface, but that's partly caused by the abundance of features that it offers. It is a fine example of what a collaborative effort can achieve, input from all sorts of levels of expertise bundled into one application.
A very slick looking application (currently only Mac OS, but a Windows beta is coming) is Affinity Photo. It's also very affordable. I'm certainly going to try that, when the Windows version becomes available. I've not yet found much about their implementation of the Contrast control, but they do offer Luminosity blending layers, so it would be workable if not as hoped.
Dogmas lead to stagnation, investigation/research leads to innovation. And FWIW, even the Bible (1 Thessalonians 5, verse 20 (https://www.biblegateway.com/passage/?search=1%20Thessalonians%205)) mentions "Do not treat prophecies with contempt but test them all; hold on to what is good, reject every kind of evil."
So there you have it. ;)
Cheers,
Bart
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If you change Contrast with the Contrast control, what is it in the image that you want to change?
The appearance as I desire. Which is what happens 9+ times out of ten when I do this via Adobe's implementation. And that 10th time? As I said, I have no problems with one more step to adjust to taste. What you simply can't fathom is that the design of the product under discussion is something well thought out that many, many users enjoy. If you don't, use another product OR learn to use that 2nd dance stop to season to taste.
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The appearance as I desire. Which is what happens 9+ times out of ten when I do this via Adobe's implementation. And that 10th time? As I said, I have no problems with one more step to adjust to taste. ......
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. There are however situations in which it is preferable to have a totally linear interpretation of an image file (i.e. without either contrast or saturation boost), one of which I wrote-up in my article on capturing colour film negatives with a digital camera, involving saving them as linear TIFF files with ColorPerfect MakeTIFF, and then inverting them in SilverFast HDR. These, however, are special-purpose implementations for which the linear option is good to have, but not something that I find efficient for normal digital photographic output compared with the Adobe implementation, which provides a very decent starting point for further refinement of normal photographs. A substantial volume of capture errors that require enormous post-capture adjustments challenging the limits of the application raise more questions about the photographer than about the app.
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Special needs require special tools (http://nuclearlight.net). :P
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The appearance as I desire. Which is what happens 9+ times out of ten when I do this via Adobe's implementation. And that 10th time? As I said, I have no problems with one more step to adjust to taste.
Fine, glad you're happy. Maybe it should be called the "Appearance slider control" then.
What you simply can't fathom is that the design of the product under discussion is something well thought out that many, many users enjoy.
I'm sure that it didn't happen without giving it any thought. However, I'd be interested in some independent research or reports on that assumed customer satisfaction, though.
You refer to thousands of happy users, but then we (you and I and several readers of this thread ;) ) also know that ignorance is bliss, and that's fine too (no need to make people aware and unhappy if a solution is out of their reach). And of course not everybody has clients with, or personally, such high expectations as some others do.
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), and who have to rely on the software doing the right thing, and they edit by number (clipping points / histogram / heuristics like skin tone Hue angle / etc.) based on experience. And portrait photographers who suffer over-saturated red-brown skin shadows when they adjust Contrast or Curves in the traditional way.
If you don't, use another product OR learn to use that 2nd dance stop to season to taste.
As I said before, the DD-shuffle does not appeal to me, therefore I do use alternatives. But I'm genuinely happy that you are happy. There's no joy in a grumpy dog, or a cat for that matter.
Cheers,
Bart
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Fine, glad you're happy. Maybe it should be called the "Appearance slider control" then.
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.
As I said before, the DD-shuffle does not appeal to me, therefore I do use alternatives
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!
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Special needs require special tools (http://nuclearlight.net). :P
Very interesting! And less expensive than: http://3dlutcreator.com
That product is very powerful based on the demo I played with months ago. I'd love to see a review/comparison with this product.
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You are aware it uses the LAB model and requires working with rendered image files.
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You are aware it uses the LAB model and requires working with rendered image files.
The PS plug-in? Yes. It does work in RGB but the FAQ says something about recommending the use of Lab which I'd avoid if possible. I'm fine that it works high bit on rendered images.
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Well, here's what their manual says:
<<As we said above, FireGrade works in the Lab color space. So your image must be in that color space, too. But what if you have a complex document with lots of mask layers and other stuff, it is in RGB or CMYK, and you do not want to switch to the Lab mode? Smart objects will come to help! Convert the layer of interest to a smart object, open the object, convert it to Lab, use FireGrade, and save the changes. If you need to do “nondestructive” editing (that is, you may want to do corrections at any moment), convert the layer inside the smart object into another smart object, and apply FireGrade. Now you can open the smart object again to make changes.>>
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Well, here's what their manual says:
<<As we said above, FireGrade works in the Lab color space. So your image must be in that color space, too. But what if you have a complex document with lots of mask layers and other stuff, it is in RGB or CMYK, and you do not want to switch to the Lab mode? Smart objects will come to help! Convert the layer of interest to a smart object, open the object, convert it to Lab, use FireGrade, and save the changes. If you need to do “nondestructive” editing (that is, you may want to do corrections at any moment), convert the layer inside the smart object into another smart object, and apply FireGrade. Now you can open the smart object again to make changes.>>
Perhaps then, the FAQ needs updating?
Q: What color modes are supported by FireGrade?
A: Lab and RGB. But only in Lab you can get expected results.
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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.
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.......and if the Manual prevails, you'll notice the added gymnastics needed to work the photos "non-destructively". I'll stick with LR, thanks.
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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):
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.......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.
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OK, once you've played perhaps start a new thread telling us what you think of it.
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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. :)
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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
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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.
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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 (http://forum.luminous-landscape.com/index.php?topic=106695.0) 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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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
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Indeed it is an old debate.
.........................
We'll see if/how Adobe addresses the subject.
Peter
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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.
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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
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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 (https://en.wikipedia.org/wiki/Color_blindness)). 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
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Protanopia and Deuteranopia subjects are not really color blind.
Tell Bart ;D
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.
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>>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.
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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".
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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.
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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.
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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
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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.
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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.
And if I recall correctly from the 2007 debate Thomas also dismissed the notion that there's anything more complicated about programming the tone curve with versus without some saturation co-behaviour, so this probably has nothing to do with technical problems needing a heap of budget and everything to do with what you say here.
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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.
The effect of Vibrance adjustments isn't hard-wired into any particular colour group (but is configured to not exaggerate skin tones). It's impact is designed to vary depending on how much saturation of a colour group the adjustment it starts out with.
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The effect of Vibrance adjustments isn't hard-wired into any particular colour group (but is configured to not exaggerate skin tones). It's impact is designed to vary depending on how much saturation of a colour group the adjustment it starts out with.
Mark, that isn't information that can be verified nor is it functionally useful. I don't know where you get these certainties that imply you know how a slider is engineered to deal with color since you've admitted you're not a software programmer. No where in your statement did you use one word that visually describes what you think is going on under the hood. I did. So I really don't understand what your point is in telling me how Vibrance is hardwired. I know what I see.
I only stated what I see comparing reducing Vibrance vs Saturation slider on a flower image that has the colors I mentioned. Increasing Vibrance does make mid tone to deep blues get darker and richer and does hold back on oranges as in skin tones. But the more I increase Vibrance it eventually affects warm colors as well.
Saturation slider is more balanced and even in applying saturation across a wider range of colors. I don't know nor has anyone proven how these two sliders are hard-wired.
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Mark, that isn't information that can be verified nor is it functionally useful. I don't know where you get these certainties that imply you know how a slider is engineered to deal with color since you've admitted you're not a software programmer.
What he wrote however is correct in that there is skin tone protection if you will with Vibrance and the way it works is, less saturated colors are affected more than higher saturated colors. It's not a linear (if you will) boost like Saturation.
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Mark, that isn't information that can be verified nor is it functionally useful. I don't know where you get these certainties that imply you know how a slider is engineered to deal with color since you've admitted you're not a software programmer. No where in your statement did you use one word that visually describes what you think is going on under the hood. I did. So I really don't understand what your point is in telling me how Vibrance is hardwired. I know what I see.
I only stated what I see comparing reducing Vibrance vs Saturation slider on a flower image that has the colors I mentioned. Increasing Vibrance does make mid tone to deep blues get darker and richer and does hold back on oranges as in skin tones. But the more I increase Vibrance it eventually affects warm colors as well.
Saturation slider is more balanced and even in applying saturation across a wider range of colors. I don't know nor has anyone proven how these two sliders are hard-wired.
I only report things here that I've either experienced myself or been told on competent, first hand authority. Take it or leave it. I have no interest in arguing with you.
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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.
Hi Jeff,
It's good to know that Thomas is pretty much in charge, but I doubt that he is not bounded by budgets and numbers of people that can be assigned to his ACR/LR team. He more than likely has to operate within such limits, and can only determine what activities he prioritizes within those bounds.
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.
So it might just be that he has many things on his list that he finds more important than improving the Contrast control. Or does he still stick to his design that in the film era was probably reasonable, but by now could do with an update but he doesn't because it apparently would require a significant effort in the shape of a new Process version, Eric Chan also said as much.
It would require an all new Process Version and I think it's simply not worth the effort.
Not worth the effort. Is that in the light of other improvements that have more impact for you or Adobe, or because you think it's not an issue anyway. Whichever it is, that's fine with me, I'm just wondering. No problem with solidarity to Thomas either, but really wouldn't you prefer to be able and avoid the issues that come with the current implementation of the Contrast control? Or to phrase it differently, would you avoid using Contrast if it gets fixed and doesn't offer a "Use Legacy" toggle?
Anyway, I've attached a ZIP archive with 3 TIFF files. They are gradient versions of 3 of the ColorChecker patches (Light Skin, Sky Blue, and Foliage), each basically with constant Hue and Saturation, but with linear Brightness going from 0 to 100%. Applying a Contrast curve to them will reveal if and how much the original constant Saturation is altered when sampled with the colorpicker in HSB mode.
Cheers,
Bart
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This thread reminds me of Plato's Allegory of the cave
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This thread reminds me of Plato's Allegory of the cave
I'm not so sure, because the people who you probably think are in a cave really aren't. They've known and thought about this issue since a long time back. I think there is just a simple disagreement about two questions: (1) is the issue important, and (2) would a substantial lessening of the linkage between contrast and saturation create a higher quality and more efficient starting point for image editing? There is no consensus here on either question and I doubt that one will emerge from this discussion. So the bottom lines are simply: (a) we wait for Adobe to decide whether they will amend this linkage going forward (they know the issue too and they know how to program either implementation) and (b) in the meanwhile, those who prefer other kinds of renderings should use the applications that provide them.
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It's good to know that Thomas is is pretty much in charge, but I doubt that he is not bounded by budgets and numbers of people that can be assigned to his ACR/LR team. He more than likely has to operate within such limits, and can only determine what activities he prioritizes within those bounds.
Yeah, ya know, I'm not gonna get into the specifics of budgets and personnel. But I'm pretty sure if Thomas wants to do something, Thomas can do it. Adobe kinda defers to the guy that wrote Photoshop ya know? The fact he's not changed Contrast kinda leads me to believe he doesn't think it's needed at this point.
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What he wrote however is correct in that there is skin tone protection if you will with Vibrance and the way it works is, less saturated colors are affected more than higher saturated colors. It's not a linear (if you will) boost like Saturation.
That's a much better and simpler to understand explanation, Andrew, thanks.
So the Saturation slider acts on color (more) linearly vs the more non-linear with Vibrance. I already knew about Vibrance's skin protection years back when it was first discussed. However, from editing over 1000 Raw files over the years it's clear to me different images add and subtract from the intensity of non-linearity depending on color content variances. On some images the Saturation slider will reduce luminance slightly in highlights of fully saturated pinkish orange sunset clouds but I'm never sure if this luminance hit caused by the gamut limit of my sRGB-ish display.
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I am a simple man, as OReilly is fond of saying. What IS saturation? Never found a good explanation.
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I am a simple man, as OReilly is fond of saying. What IS saturation? Never found a good explanation.
Hi,
It depends on context (http://depends on context).
In this thread's context, it's known as Colorfulness or purity of color, see here (https://en.wikipedia.org/wiki/Colorfulness) for a more precise description ("Saturation is the colorfulness of a color relative to its own brightness").
So when the relative ratio between the dominant colorchannels changes, i.e. dominant R, G, or, B increases or the others decrease, Saturation changes. Contrast on the other hand is when a given color reflects or emits more of the same color, e.g. when shaded from illumination or more illumination is added.
Then there is also the psychophysical aspect, where human vision play a lot of tricks on what we see, but that is beyond the scope of this thread, but it does play a role. For handling that, Color Appearance Models (e.g. CIECAM02 (https://en.wikipedia.org/wiki/CIECAM02)) are designed, and they too (have to) treat Chroma and Luminance separately.
Cheers,
Bart
P.S. And for those who mistakenly think that a better tamed implementation of a Contrast control would lead to unsaturated and dull colors, I've attached a reprocessed (with C1 Pro version 9) version of an older image of mine.
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I am a simple man, as OReilly is fond of saying. What IS saturation? Never found a good explanation.
Colorfulness:
https://en.wikipedia.org/wiki/Colorfulness
http://rit-mcsl.org/fairchild/PDFs/AppearanceLec.pdf (http://rit-mcsl.org/fairchild/PDFs/AppearanceLec.pdf)
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Thanks Andrew - the PDF is very good.
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So saturation is like porn. We know it when we see it, but we can't explain it.
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So saturation is like porn. We know it when we see it, but we can't explain it.
I'd be happy to explain porn to you ;D
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Ten minutes of sophistry and hand waving, as W L Root used to say.
So if contrast also adjusts saturation, then some sort of reciprocity theorem tells me adjusting saturation also adjusts contrast.
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P.S. And for those who mistakenly think that a better tamed implementation of a Contrast control would lead to unsaturated and dull colors, I've attached a reprocessed (with C1 Pro version 9) version of an older image of mine.
That's the first I've seen of that image so I don't know what to compare it with to support your point. I don't see dull colors in that (C1 Pro version9) Beach Slide image, but then I don't know what it looked like before you added contrast that would affect saturation more or less to a degree.
The issue with adding contrast is that it's subjective on how dark the user wants the shadows. So that slide image could start out sort of unnaturally flat looking more or less and then the user decides the shadows need to look overly dark thus increasing saturation.
We don't know how that image started out so it would be more informative to show a progression of individual edits representing increased contrast to get an idea how well C1 Pro's controls saturation applying more contrast.
Nice looking image BTW, Bart.
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Ten minutes of sophistry and hand waving, as W L Root used to say.
So if contrast also adjusts saturation, then some sort of reciprocity theorem tells me adjusting saturation also adjusts contrast.
I guess so and dependent on which software application you are using to render raw files, Your camera manufacturer's software, ACR / Lightroom, DxO optics pro, Capture One Pro, and any other raw processing application the resulting tone and colour will be different.
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That's the first I've seen of that image so I don't know what to compare it with to support your point. I don't see dull colors in that (C1 Pro version9) Beach Slide image, but then I don't know what it looked like before you added contrast that would affect saturation more or less to a degree.
Hi Tim,
The main purpose of adding that image was to caution some people against getting the wrong idea about suppressing the Saturation boost. It does not make images look dull. And over-saturated Contrast enhanced images also do not have to look over-saturated, because there are tools to somewhat correct that. However (!), since the Contrast induced Saturation changes are highly non-linear, it is almost impossible to fully correct it (should one wish to).
The issue with adding contrast is that it's subjective on how dark the user wants the shadows. So that slide image could start out sort of unnaturally flat looking more or less and then the user decides the shadows need to look overly dark thus increasing saturation.
Yes, the amount of contrast we bestow on an image is rather subjective, and also depends on the scene contrast, and whether we used proper technique to capture the image to begin with. People e.g. tend to underestimate the benefits of using a properly dimensioned lens hood, it improves overall Contrast and Saturation. A foggy scene may not improve if we attempt to fill the histogram, and adding non-linear Contrast will also affect the highlight roll-off, which is why I already start with a linear tone curve (to avoid adding a Contrast roll-off to the already added roll-off of a more film curve response).
We don't know how that image started out so it would be more informative to show a progression of individual edits representing increased contrast to get an idea how well C1 Pro's controls saturation applying more contrast.
Nice looking image BTW, Bart.
Thanks. A problem with showing a progression of editing steps, besides the subjective choices (some of which are subtle), is that it does not convey the actual user experience of not having to second guess if the color we currently see is somewhat resembling the captured color (after the camera profile added its flavor of rendering).
Also, not everybody has 'perfect' color vision or memory, and there are psycho-physical factors involved that I mentioned earlier (automatic adaptation to the current image colors, even if they are wrong, e.g. White-Balance). So it's mentally easier to start with 'correct' Saturation and add to flavor, than starting with the 'wrong' Saturation and remove to flavor (which is almost impossible to do perfectly due to non-linear Saturation changes). Also every time Contrast is changed with the traditional approach, Saturation should be checked again. And many people settle for good enough is good enough, and what's good enough for one, isn't necessarily the same for another.
I currently can open, but cannot edit, some(!) TIFFs in Capture One version 9 (despite enabling that in the preferences), so I cannot show a side by side comparison (TIFF input should avoid Raw converter / profile differences) with e.g. ACR/LR. I'll have to figure that out first. Not that I normally use Capture One for my postprocessing, but it can occasionally be useful.
Cheers,
Bart
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Bart, so no on the contrast progression demo.
Too bad. I would've liked to see just how well C1 Pro applies it because that Topaz video gave undesirable results. I can't use C1 Pro because I don't have a current OS that supports it.
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Bart, so no on the contrast progression demo.
For the moment Tim, but don't despair ;)
I may yet solve the issue, and show something side by side, maybe even a video.
Too bad. I would've liked to see just how well C1 Pro applies it because that Topaz video gave undesirable results. I can't use C1 Pro because I don't have a current OS that supports it.
When I get a bit more time, or solve the issue with some CGI test images, I'll put something together that allows to compare with ACR/LR.
Cheers,
Bart
P.S. It's a pity that ACR/LR doesn't offer an option, like in Photoshop (luminosty blending) but I understand that PS uses a different (non-parametric but layer based) processing workflow.
An application like Photoline offers even better tool options than Photoshop. It allows to choose the colorspace in the Curves tool (see attached), as it will be applied to a layer, or it allows to add it as a separate adjustment layer.