ACR 4.4 and Clarity

[digitaldog]

I'm not saying it can't be corrected for (that's what the calibration tab does, even if it has only six out of the eight controls it ought to have), I am simply pointing out that the software ships with a built in bias, according to a large number of user reports.
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In terms of your idea of large number and mine, we'll have to agree to disagree. Since the fix is easy, its probably moot anyway. Rendering is subjective.

[Panopeeper]

Well, why not?  If one is going to offer the possibility to do user calibration, why not offer the full latitude of possible adjustments?

The transformation relates to a given illuminant; I think that's the reason, that three values are fixed. The DNG file usually contains two sets of transformation matrixes for two different illuminants; the matrix used in the actual transformation has to be interpolated based on the actual illuminant, and that step will "fill" the missing values. In other words, if the entire matrix was specified based on illuminant-independent parameters, then the conversion could not take the actual illumination in account.

[ejmartin]

The transformation relates to a given illuminant; I think that's the reason, that three values are fixed. The DNG file usually contains two sets of transformation matrixes for two different illuminants; the matrix used in the actual transformation has to be interpolated based on the actual illuminant, and that step will "fill" the missing values. In other words, if the entire matrix was specified based on illuminant-independent parameters, then the conversion could not take the actual illumination in account.
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That makes sense.  Thanks.

[ejmartin]

In terms of your idea of large number and mine, we'll have to agree to disagree.
[a href=\"index.php?act=findpost&pid=188776\"][{POST_SNAPBACK}][/a]

I don't want to quibble about the definition of "large number".  The point which you seem to want to ignore is that well over 95% of the people who have bothered to report their calibration settings on the internet have reported values in the same direction away from zero calibration adjustment.

[eronald]

I'm not going to pick any fights here with the existing ACR implementation - It has done a great job of getting the existing userbase into the Raw world.

However, I believe that it's time the sophisticated user were offered the overrides which are very carefully built into the DNG specification, that the physics of the phenomena involved be discussed in the appropriate forum, which is the ICC Digital Photo Workgroup, and then a camera calibration model ie. cam2xyz be standardized by the industry by means of the ICC.

Photoshop was substantially improved by incorporating standardized color management tools - wouldn't you agree, Andrew? ACR is fast approaching the same degree of maturity.

I talked with Jenoptik/Sinar earlier this week, had a discussion on this topic with some color specialists at Xrite yesterday, I've just scheduled presentation to Fuji next week regarding this topic, and the Adobe guys have said we should talk about this by the end of the month. The very fact that so many parties are talking confirms the fact that over-arching color management is starting to make sense to many people involved in the industry.

I've been told by two sources that there appear to be some technical hurdles why 3x3 matrices are simply not enough even for ONE camera in ONE lighting condition - apparently camera metamerism is a persistent nuisance.

Edmund

[Philmar]

YIKES!! Clarity RE-hijacked -  

Why DO people get so miffed at having to calibrate ACR? A RAW converter is just a tool. Adobe gave us a way to calibrate it to get the results we need. Yes it is a PITA to do it but it's intuitive workflow, ease of use and large amount of control make the program a gem once you bother to calibrate it. Sure I find DPP gives a better initial rendering of the colors but I HATE it’s crude clunky interface and lack of certain controls (i.e. highlight control, chrom aberration ect.). I couldn’t care less whether ACR needs to be calibrated due to someone at Adobe's perceived agenda, laziness, incompetence or haste. All I know is that once calibrated, it is a great tool. One that I want to learn better how to use...which is my segueway back to the clarity slider.

The 100% view is useful for evaluating the appearance of halos. Otherwise it is best to use it with the image in full screen mode allowing you to assess its aesthetic impact on the photograph - which does vary from image to image and according to the taste of the photographer. When the image starts looking artificially "clarified", back it off a bit. I also leave a bit of headroom for capture sharpening because the combined effect of the two can be a bit much, but this as well is largely a matter of taste.
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Thanks for your reply.
"When the image starts looking artificially clarified".  Since it's definition doesn't really mean much to me I'll take it as when the image starts to"suck"  . That's what I had been doing but always scaling even further down. But thanks to your explanation I will endeavor to be even bolder.

Do people apply Clarity to most of their shots?
How much? Yes I know it depends on the shot but are there any general rules of thumb?
Are there types of photos (i.e. like hazy day shots, shot from a long focal length lens) that benefit more from Clarity than others?
Are there types of photos where use of Clarity would be of no benefit?

[Panopeeper]

Why DO people get so miffed at having to calibrate ACR?

Some of those, who get so miffed came to the conclusion, that no amount of calibration can achieve what they want to get.

A RAW converter is just a tool

Really?

Sure I find DPP gives a better initial rendering of the colors but I HATE it’s crude clunky interface and lack of certain controls (i.e. highlight control, chrom aberration ect.)

Good news for you: DPP DOES have CA control. Moreover, it has controls for vignetting correction (like ACR), distortion correction (unlike ACR), and some more - all this with the knowledge of the lens.

Still, the UI and functions of ACR are better than DPP, but it is not always a disadvantage to know your tool's functions.

[ejmartin]

Why DO people get so miffed at having to calibrate ACR? A RAW converter is just a tool. Adobe gave us a way to calibrate it to get the results we need.
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Suppose that every lens that Canon sold had the autofocus miscalibrated to front focus by (on average) one DOF, but gave the user an AF adjust feature.  So each user is required to go through a calibration procedure for their lens to focus properly.

Oh wait, that's pretty close to reality  

Why DO people get so miffed at Canon quality control?  A lens is just a tool.  Canon gave us a way to calibrate it to get the results we need  

[digitaldog]

I don't want to quibble about the definition of "large number".  The point which you seem to want to ignore is that well over 95% of the people who have bothered to report their calibration settings on the internet have reported values in the same direction away from zero calibration adjustment.
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95% of 5% of all users isn't a statistically compelling reason to alter the code. When you have some real numbers, lets talk.

[digitaldog]

However, I believe that it's time the sophisticated user were offered the overrides which are very carefully built into the DNG specification, that the physics of the phenomena involved be discussed in the appropriate forum, which is the ICC Digital Photo Workgroup, and then a camera calibration model ie. cam2xyz be standardized by the industry by means of the ICC.

I suggest you do your darnedest to get on that committee and effect this change. When you're a few years shy of this happening, let us know so we can be ready for it.

In the meantime, there's a solution in search of a problem that as yet, no one on the your side wishes to discuss. That's that simple question posed about rendering and ICC profiles.

[ejmartin]

95% of 5% of all users isn't a statistically compelling reason to alter the code. When you have some real numbers, lets talk.
[a href=\"index.php?act=findpost&pid=188854\"][{POST_SNAPBACK}][/a]

Um, not statistically compelling?  Sampling theory says otherwise.  Pollsters don't have to canvas everyone to get an accurate picture of the electorate; epidemiologists don't need to study the entire population to assess disease prevalence.  

Unless you have a reason to suspect that the sample is for some bizarre reason biased to report calibration adjustments all in the same direction, 95% of 5% of all users IS statistically significant.  Quite a bit.

[duraace]

Clarity's one of the best adjustments there is.  It's usually the first one I touch, and I add Clarity to every photo.  LR = non destructive editing = optimized images.  What's not to want??

[Schewe]

I don't want to quibble about the definition of "large number".
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Due to some info that Andrew and I are privy to, it's really, really not worth arguing about this at this stage. In the not too distant future, all of this discussion will be moot.

[eronald]

I suggest you do your darnedest to get on that committee and effect this change. When you're a few years shy of this happening, let us know so we can be ready for it.

In the meantime, there's a solution in search of a problem that as yet, no one on the your side wishes to discuss. That's that simple question posed about rendering and ICC profiles.
[a href=\"index.php?act=findpost&pid=188855\"][{POST_SNAPBACK}][/a]

Andrew -

 I am on that ICC committee, and I am doing my utmost to effect that change; and in fact it does seem like things are moving.

 I really wish you would get on board - after all you did benefit considerably from the standardization of the print color process, and so do understand that standardization gives consultants a *portable* competence. And that did happen within your lifetime

Edmund

[bjanes]

In terms of your idea of large number and mine, we'll have to agree to disagree. Since the fix is easy, its probably moot anyway. Rendering is subjective.
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As to sampling size, I would say if you flip a coin 20 times and it comes up heads 19 times, something is wrong and you do not need to extend the sample size. The thread referenced by Prof. Martinec gives good evidence of a systematic bias of a negative red hue and positive red saturation. On the other hand, Digidog has presented no data whatsoever. Perhaps he is relying on the three cameras tested by Bruce Fraser and Jeff Schewe and mentioned by Jeff in the referenced thread as showing random variations.

Rendering is subjective, but a ΔE* is not, especially when corrected for chroma (saturation) and luminance (exposure). Many observers favor increased chroma, but few favor orange reds as rendered by default by ACR in many cases. A typical result is shown below. The red patch (#15) is strongly shifted towards orange.

[Philmar]

Suppose that every lens that Canon sold had the autofocus miscalibrated to front focus by (on average) one DOF, but gave the user an AF adjust feature.  So each user is required to go through a calibration procedure for their lens to focus properly.

Oh wait, that's pretty close to reality   

Why DO people get so miffed at Canon quality control?  A lens is just a tool.  Canon gave us a way to calibrate it to get the results we need 
[a href=\"index.php?act=findpost&pid=188834\"][{POST_SNAPBACK}][/a]

OK let's suppose there were inter-camera differences in how they interacted with lenses. It wouldn't bother me that much if I had to calibrate my lens to my specific camera if once I calibrated the lens I knew that forevermore it would work fine and be tack sharp.

ACR isn't perfect - calibrate it and forget it - that's my philosophy. I have too little time too speculate why it initially isn't perfect. I'd rather spend my energy doing what it takes to make it as useful as possible i.e. calibrate it. Don't get me wrong. I enjoy reading the banter about the subject and admire everyone's depth of knowledge on all these matters.
Right now I just want to understand the clarity slider. Maybe if I was as knowledgeable as all you folk I'd concern myself with these esoteric matters. So carry on with the enlightening and interesting dialogue but please do, if you have the moment, discuss the 'clarity slider, and some of my earlier queries. Thanks!

[Philmar]

Clarity's one of the best adjustments there is.  It's usually the first one I touch, and I add Clarity to every photo.  LR = non destructive editing = optimized images.  What's not to want??
[a href=\"index.php?act=findpost&pid=188869\"][{POST_SNAPBACK}][/a]

Thanks. every photo? But how much? Yes I know it depends on the shot but are there any general rules of thumb?
Are there types of photos (i.e. like hazy day shots, shot from a long focal length lens) that benefit more from Clarity than others?
Are there types of photos where use of Clarity would be of no benefit?

[digitaldog]

Andrew -

 I am on that ICC committee, and I am doing my utmost to effect that change; and in fact it does seem like things are moving.

 I really wish you would get on board - after all you did benefit considerably from the standardization of the print color process, and so do understand that standardization gives consultants a *portable* competence. And that did happen within your lifetime

Edmund
[a href=\"index.php?act=findpost&pid=188893\"][{POST_SNAPBACK}][/a]

I'm on that board in some capacity so I have some idea how things move. I wish them all luck and would add, all their efforts are appreciated. But so far, there's a big solution in search of a problem I've yet to see anyone on your side define. Until that happens, or the technology improves to the degree we can actually measure the scene illuminant, the current solutions are half baked.

[digitaldog]

As it is now, this has not happened. Adobe has not provided a straightforward, exact way to achieve the best color conversion. The profiles created with the Forst and Rags scripts are based on three (or four?) squares of the Gretag checker and the result is still not as good as for example Canon's DPP is creating.
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Profile created?

[madmanchan]

Keep in mind that doing ACR calibration with a script is not going to get you what DPP (or Nikon's View/Capture NX) produce. No colorimetric characterization is going to get you there, since generally DPP and NX's renderings aren't really colorimetric. In fact, aside from the deep reds issue, ACR generally reproduces hues more accurately than DPP does (esp. its 'Standard' rendering, which is the default). It is true that ACR (indirectly) biases deep reds towards orange but on the other hand DPP biases deep oranges towards red (i.e., the other way around).

DPP, NX, and most of the vendor software perform non-linear hue twists that are apparently based more on the vendors' notions of what people want to see (i.e., the color rendering style) rather than being colorimetric or 'accurate'. No matrix is going to reproduce this.

My suggestion would be to re-read Jeff Schewe's last post carefully.