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Newb: out of gamut colors and color shift

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  #51  
Old 01-17-2011, 06:05 PM
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Markzebra Markzebra is offline
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Re: Newb: out of gamut colors and color shift

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Andrew revs his car up to 65MPH, turns on the cruise control and then presses the coast button until the speedometer reaches 50 at which point he releases the coast button.
…yes, to extend your analogy MrMonday, he seems to be recommending that everyone does this. Unfortunately its a deeply flawed, fuel wasting process, that doesn't produce the best results. And traffic accidents increase by about 800% in two weeks.
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  #52  
Old 01-17-2011, 06:08 PM
creativeretouch creativeretouch is offline
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Re: Newb: out of gamut colors and color shift

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Originally Posted by andrewrodney View Post
You don’t have manual control over the conversion other than picking a rendering intent!

You have control over the data prior to the conversion, fine. No argument. I do this as well. So again, you see the overlay. It tells you something is out of gamut. Then what?

Or you invoke a soft proof and again, while in the RGB wider gamut space, you see what the image should look like IF you convert.

In either case, you can obviously edit the image. In one case you see the image as it would appear if you convert in its entirety. In the 2nd case, you could see the same thing, but all out of gamut colors are hidden by an overlay.

Given the two scenario’s, how is having the image blocked useful and what do you then do?

Again, having a manual approach to editing an image isn’t the debate here. Having a view that blocks what you are seeing, and how you deal with it hasn’t been described nor how that is in any way helpful. Any out of gamut colors, no matter what you do with or without the overlay get converted (clipped) upon conversion. Messing around prior to the conversion is one thing, but anything out of gamut gets affected, its as simple as that. Other colors get affected too.



Specifically why and how is what’s missing.
I am sorry, I do not have exact mathematical formula for my workflow. I have tried to give you the answer above and I do not wish to repeat myself again and again.
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  #53  
Old 01-17-2011, 06:20 PM
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andrewrodney andrewrodney is offline
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Re: Newb: out of gamut colors and color shift

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Originally Posted by Markzebra View Post
The vast majority of people here will be outputting for a gloss stock.
And no other output device. And you know this fact how? The poll data would be where?

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This provides a good enough ballpark for Gamut Warning and Proof setup to be useful.
Useful how? That’s what’s totally missing from your posts (among other things). Specifically the Gamut Warning overlay.

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And is much better than just ignoring profiling, and retouching in an enormous space like Pro-Photo, which you seem to be in practice suggesting.
Better how and why? Again, not discussed. You said sRGB in more than one post, but sRGB can’t contain the CMYK gamut discussed. Cyans and green fall outside CMYK (SWOP V2) gamut. So bigger? Which space and why?

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Unfortunately you are very much in the minority, if you are seriously suggesting this.
And that makes your points technically correct? The sentence is moot. I’ve pointed to an Adobe white paper that clearly explains why a wide gamut working space is useful. Your turn.

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Because most color professionals, including the late Bruce Fraser would not recommend it. For very good reason.
Funny you should mention Bruce, a partner of mine in Pixel Genius, someone who consulted with Kodak when creating ProPhoto RGB and someone who did recommend it as a working space. Start here: http://www.luminous-landscape.com/tu...hoto-rgb.shtml
Quote:
One of the most knowledgeable voices in the area of colour management over the last few years has been Bruce Fraser, the co-author of the current definitive work on colour management for photographers – Real World Color Management. In articles that he's written elsewhere Bruce suggests that digital photographers should consider working in the much large ProPhoto RGB colour space. (ProPhoto RGB was developed by Kodak).
------------

So wrong again.
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Ah so its about terminology now is it. Fair enough, thats better than being accused of misinformation. Ok simply then, and not couched in techno-babble for the insecure - there are two intents of value to practicing Retouchers, Relative and Perceptual. Perceptual adjusts the colors within the image to attempt to create a 'smooth' and perceptually accurate conversion, but is more liable to undersaturate colors within the in-gamut areas of the image. Which is precisely as I said before. Relative …
It has nothing to do with smoothness, I explained that. Your ideas about these rendering intents are incorrect. You can call it techno-babble which is code for “I don’t understand and to dismiss it, I’ll call it techno-babble”.

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Thats extending the argument, into an area I didn't make.
You most certainly did. But even if you didn’t, writing incorrect ideas about color management doesn’t get you off the hook.

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For many profiles it is damaging and flattens the saturated color extremes into unmodulated flat areas.
Many? OK which ones, built by whom, output to what devices? You have the actual output you can share? Many profiles means how many?

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This example also demonstrates the unwiseness of retouching without this knowledge in very subtle, saturated areas, in a space like ProPhoto RGB or even the more sensible Adobe RGB.
That’s your science? So you are sure this is the case with all profiles? Or maybe poorly built profiles or generic profiles used on devices that don’t behave as the profile is built to define? You are sure this is the effect of the working space? You converted using sRGB and said profile, then Adobe RGB (1998) and ProPhoto RGB and only the working space part of this conversion caused these issue? You can of course provide these profiles for us to test?

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That is the practical tradeoff between Relative and Perceptual, both compromises. As I said when i first brought up the distinction.
I agree with sentence 1 above, the 2nd was never distinct.

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Maybe, but certainly not bad advice for anyone deciding whether to use Perceptual or Relative to convert their images. You have then gone on, to unecessarily regurgitate information which I, and many others here, will already be aware of.
Thanks for speaking for all other readers of this post.

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Which all brings us to the main point …
About time you got there....

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So lets summarize then. This method of color correction and working with color that you propose means that its practically impossible to see colors on your monitor that resemble in any way how they will appear in print.
Not so. What makes you believe this?
That’s not the main point...

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Because most people don't know what Proof Setup is, or does.
Most people? You’ve decided this is a fact how? And even if so, its certainly not your job to tell them how it works I gather. It is my job.

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The Rendering Intents, are depended on to squeeze whatever into CMYK.
CMYK or RGB. Depended on to squeeze? Confusing. English may be your 2nd language, if so, forgive me but that is quite unclear.

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This process in its practical application, unfortunately, at a stroke, invalidates your whole argument.
Another sentence I don’t understand. Clarify what you are asking.

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Your implied viewpoint that is that on screen proofing has no value.
Not at all and never stated as such. Just the opposite! The Customize Proof Setup is very, very useful! I said that above. Try reading the posts again. I’ve gone to great lengths to explain how useful it is: (http://seminars.adobe.acrobat.com/p84783897/) (http://www.ppmag.com/reviews/200409_rodneycm.pdf) (http://www.ppmag.com/reviews/200411_rodneycm.pdf)
(http://www.ppmag.com/reviews/200410_rodneycm.pdf)

What I’ve said is the ugly, solid overlay that treats all degree of out of gamut colors the same has little value (basically useless). At least until someone provides steps to show me otherwise, something you have still not done. Rather, you would prefer to degrees into color management and color science, something you speak poorly.

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And that everyone should be retouching in high gamut RGB spaces, with no reference to, or awareness of the CMYK destination.
Read the Adobe white paper again! Yes, anyone working with raw source data should ideally be encoding from the raw converter into ProPhoto RGB. From there, lots of possibilities. Doing otherwise simply throws away colors that the capture device and many output devices can utilize.

Would you care to see the color gamut of a decent scanner? Cause its way, way bigger than sRGB and people have been going off to CMYK from scanned data for decades.

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This is both in terms of basic advice and technique, incorrect I'm afraid.[/B] And it is not a viewpoint supported by most color professionals.
Again, its interesting you have the ear of the profession and speak for them. Could we say it is not a viewpoint supported by most color professionals who like yourself, need a bit more education into color management?

Quote:
Which all brings us to the main point …
So NOW you’ll provide a step by step process with an explanation of how the overlay for the gamut warning is useful?

Last edited by andrewrodney; 01-17-2011 at 06:27 PM.
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  #54  
Old 01-17-2011, 06:23 PM
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andrewrodney andrewrodney is offline
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Re: Newb: out of gamut colors and color shift

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Originally Posted by creativeretouch View Post
I am sorry, I do not have exact mathematical formula for my workflow. I have tried to give you the answer above and I do not wish to repeat myself again and again.
I’m not asking for math! A simple step by step tutorial, explaining what I’m supposed to SEE and do with the overlay would be more than enough.

You’ve convinced yourself that using the overlay is useful, fine. Now pretend I and other lurkers here need a tutorial as to its usefulness. What do we do, what are we looking for under the overlay, how do we use it as opposed to just keeping it off and looking at the soft proof. Will not take a lick of math!
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  #55  
Old 01-17-2011, 06:46 PM
creativeretouch creativeretouch is offline
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Re: Newb: out of gamut colors and color shift

I HAVE FOUND THE GAMUT WARNING TOOL USEFUL AS IT SHOWS ME THE LIMITS OF THE COLORSPACE WHICH IS SETUP IN MY COLOR PREFERENCES. SO I AM ABLE TO ADJUST THESE COLORS (out of gamut) AND THE OTHER COLORS AS WELL (within gamut) AND FINALY GET THE RESULT I AM HAPPY WITH.

I would like to suggest to anyone who would like to learn something about the color theory to read this book:

Photoshop LAB Color: The Canyon Conundrum and Other Adventures in the Most Powerful Colorspace
http://www.amazon.com/Photoshop-LAB-.../dp/0321356780

PLEASE TAKE IT AS MY PERSONAL OPINION ...
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  #56  
Old 01-17-2011, 07:03 PM
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mistermonday mistermonday is offline
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Re: Newb: out of gamut colors and color shift

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Originally Posted by creativeretouch View Post
I would like to suggest to anyone who would like to learn something about the color theory to read this book:

Photoshop LAB Color: The Canyon Conundrum and Other Adventures in the Most Powerful Colorspace
http://www.amazon.com/Photoshop-LAB-.../dp/0321356780

PLEASE TAKE IT AS MY PERSONAL OPINION ...
Oooooh, reference to the LAB bible is likely to deflect this thread off onto a totally orthogonal trajectory. Perhaps an effort should be made to drive this thread to peaceful parking lot.
Regards, Murray
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  #57  
Old 01-17-2011, 07:05 PM
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andrewrodney andrewrodney is offline
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Re: Newb: out of gamut colors and color shift

Well other than the use of key caps, I suppose proof of concept is not forthcoming....
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  #58  
Old 01-18-2011, 12:53 AM
5nap5hot 5nap5hot is offline
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Re: Newb: out of gamut colors and color shift

Ok I have another question!

Is it more important to look at the proof colors and make sure that the image looks good, or is it better to reduce the saturation according to the gamut warning?

I looked at some of my images for this project under the proper ICC proof colors and they look good. There are some differences.. but good.
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  #59  
Old 01-18-2011, 02:53 AM
creativeretouch creativeretouch is offline
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Re: Newb: out of gamut colors and color shift

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Originally Posted by mistermonday View Post
I could never see myself redoing hours of work destined for narrow color space output when the customer comes back and subsequently wants output for a large gamut color space. Instead I maintain a 16 bit workflow, usually ProPhoto, retaining as much of the capture device as possible. In practice I find when soft proofing, one of the rendering intents provides a very acceptable view and I did not need to sacrifice a ton of saturation to avoid gamut warnings.
I would say a gamut warning is a fastest soft proofing tool which helps me to save hours of my time working on colors which I will not be able to reroduce.
This "ugly" color helps me to define areas which I should be aware of instead of looking at "a nice soft proof" spending time to try find all colors which were changed.

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Originally Posted by andrewrodney View Post
Well other than the use of key caps, I suppose proof of concept is not forthcoming....
I have used key caps as I am really surprised I am having this kind of discusion with the guy who is so close to Photoshop and asking me same question again and again and again. Instead of respecting the workflow of the other people who may have a different style.

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Originally Posted by 5nap5hot View Post
Ok I have another question!

Is it more important to look at the proof colors and make sure that the image looks good, or is it better to reduce the saturation according to the gamut warning?

I looked at some of my images for this project under the proper ICC proof colors and they look good. There are some differences.. but good.
As long as you are happy with your colors everything should be OK. If you are not happy, you can use a soft proof to adjust oversaturated colors or you can use a gamut warning (isn't it some kind of soft proof as well ??? ) to adjust oversaturated colors.

Quote:
Originally Posted by mistermonday View Post
Oooooh, reference to the LAB bible is likely to deflect this thread off onto a totally orthogonal trajectory. Perhaps an effort should be made to drive this thread to peaceful parking lot.
Regards, Murray
I have mentioned LAB as you can get very quickly colors which are out of RGB/CMYK gamut, can't you? In the other way a LAB color space will help you to get as much as is possible from other color spaces (RGB/CMYK).
I tried to stay away of this color space as long as it was possible ...

Are going to ask me "why do you use a LAB color space when I have found it useless? And it is older than Photoshop?" Please don't ...

And guys, are we able to adjust oversaturated colors with D&B? If the answer is yes, which D&B technique is the best for this purpose?
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  #60  
Old 01-18-2011, 07:36 AM
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Re: Newb: out of gamut colors and color shift

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Originally Posted by creativeretouch View Post
I would say a gamut warning is a fastest soft proofing tool which helps me to save hours of my time working on colors which I will not be able to reroduce.
This "ugly" color helps me to define areas which I should be aware of instead of looking at "a nice soft proof" spending time to try find all colors which were changed.

I don't know about you, but I have been pixel pushing for a long time. Technology continually advances. As I look back at older work, I wish I had not boxed myself into a corner limiting an edit to what was reproducable then but which is far inferior to what is reproducable now. Using the gamut warning as a "paint by numbers" guide, does not allow me to push an image to its potential in terms of where it might go next week or next year. Why the heck would you throw out all of that color information and potentially have to do the work all over again from a raw file when you can keep it all and convert for different output intents. Andrew's analogy reagarding the gallon of water is quite appropriate.

I have mentioned LAB as you can get very quickly colors which are out of RGB/CMYK gamut, can't you? In the other way a LAB color space will help you to get as much as is possible from other color spaces (RGB/CMYK).
I tried to stay away of this color space as long as it was possible ...

Are going to ask me "why do you use a LAB color space when I have found it useless? And it is older than Photoshop?" Please don't ...

I have a very close attachment to that LAB book. I have been through every word in it - twice, and I understand it all. I may have spent more hours in LAB than you have been retouching in total. And no, I do not see it as useless. However, I fail to see your reference to it as useful to the subject of this post.

And guys, are we able to adjust oversaturated colors with D&B? If the answer is yes, which D&B technique is the best for this purpose?

There are a number of techniques for saturation adjustment just as there are a number of different methods to accomplish D&B. I have my preferences, you have yours. We both end up in the same place. I think I made that point above. Live and let live. However, that being said, I believe there are situations where certain actions make more sense, like sharpening for output at the end of certain workflows as opposed to the beginning. Or doing D&B using an adjustment layer versus the actual D&B tools, on certain images. Or performing other operations non destructively instead of destructively. I can not condemn one method over another but just point out the potential downside. I think Andrew is only try to do the same regarding the gamut warning.

Regards, Murray
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