Why Use ProPhoto RGB Color Space With a Standard Gamut Monitor?

[TomBrooklyn]

1.    Is there any benefit to using the ProPhoto color space when one's monitor is only standard (sRGB) gamut?

1a.   Ditto Adobe RGB with a standard gamut monitor.

- What is the use of retaining more colors if you can't see them?

2.   Are there any possible DISadvantages to using a wider colorspace than you can see?  

3.   If printing, how can you softproof your photos and visualize the printer output, if the file contains colors you can't see on your monitor?

[trying_to_explain]

Calibrating and profiling makes the monitor display sRGB (or whatever) correctly and accurately. It has nothing to do with the point I am trying to make. Ditto soft-proofing unless you are suggesting all editing is done on a trial-and-error basis even when the end result is for the web.

I think we are at cross-purposes and discussing different topics, that's why we are not communicating well.

I should also elucidate regarding my comment about being unhelpful. I didn't mean to say you were being unhelpful, just that what was said was unhelpful because I thought it wasn't relevant. I apologise if it was taken the wrong way.

[station_two]

trying to explain wrote:

Calibrating and profiling makes the monitor display sRGB (or whatever) correctly and accurately. It has nothing to do with the point I am trying to make…

You have no idea what the he!! you're talking about.  I'm out of this futile interchange with you. 

[station_two]

trying to explain wrote:

…even when the end result is for the web…

I am not concerned with "the web" in the least.  If it's not for print, it doesn't matter to me.  No one has any control over how images look like to the 97% of web users who view images in uncalibrated monitors through non-color-managed web browsers.

Just FYI, I work exclusively in ProPhoto RGB, "the only color space real men use." 

[CaramelMacchiato]

Perhaps that you want to do some further reading.

http://photoshopnews.com/2006/11/28/new-adobe-digital-photography-primers/

Read and research some topic on your own. If you need some further help, you know where to look for some help - here at Adobe Forums.

I'll just leave at that aside.

Best of luck!

[trying_to_explain]

Add first Bruce Fraser and then Andrew Rodney respectively

I think it is Bruce that has done a series of vids on YouTube about this, I've only got to the end of the first one so far. Can you tell?

[CaramelMacchiato]

And, add Jeff Schewe to your search queries!

[CaramelMacchiato]

Amen!

>Honestly, you need to do a lot of reading on the subjects of printing, color management, soft proofing and gamut warning.

[Lundberg02]

Let's try to tell the children about sex.  You shoot RAW because it captures the most color at the present time. You open RAW in ACR or some other processor and do your processing. Then you use Pro Photo working space in Photoshop to  do other things. The you RENDER into output space, using perceptual or relative to keep a balanced version of the wider space of the RAW capture. This retains greens, yellows, oranges, maybe some reds and blues and brings them into output space without clipping, not at their original values but with a fuller palette in the output space. All this presumes that you are working using a CALIBRATED monitor that shows you all it can, faithfully. You end up with color that is rich because it is NOT CLIPPED.

[trying_to_explain]

The peasants are revolting!

Here's a quote from an article on photo.net:

This process, called display compensation, converts on the fly, the RGB values of the pixels in your photo from your editing space used for performing corrections, to your monitor profile.

In other words, regardless of the color space you are using in your editor, the output IS CONVERTED to sRGB if you have an sRGB monitor.

Which, I believe, is what I speculated in my first post. I couldn't see it working otherwise.

[station_two]

trying to explain wrote:

…Here's a quote from an article on photo.net:

This process, called display compensation, converts on the fly, the RGB values of the pixels in your photo from your editing space used for performing corrections, to your monitor profile.

In other words, regardless of the color space you are using in your editor, the output IS CONVERTED to sRGB if you have an sRGB monitor.

Just because you have what you call an "sRGB Monitor", does not mean that your monitor profile is exactly sRGB.  Your Monitor Profile is what you saved after finishing the calibration and profiling of your particular monitor.  It is a device-dependent color profile.  sRGB is a device-independent standard color space.

sRGB is a well defined standard.  It should NEVER be used as a monitor profile.

Calling any monitor an "sRGB monitor" is inaccurate.  At best you can say that your monitor's individual color profile is within or near the limits of the gamut of the standard sRGB color space.

Huge difference.

Photoshop will use that device-dependent MONITOR profile to convert the image before sending it to your screen.

Your monitor can only display what its gamut allows it to, that is obvious.  But that doesn't mean that you're limited to working in that color space‚ not by a long shot.

[trying_to_explain]

Just because you have what you call an "sRGB Monitor", does not mean that your monitor profile is exactly sRGB.

I concur.

I thought it unneccessary to dwell on a point that was unimportant within the context of my initial query.

[CaramelMacchiato]

Agreed!

When working with certain photo editing, when using ProPhoto RGB workflow, it is wise to use a calibrated monitor.

Otherwise, if don't do proper calibrated monitor - photo editing workflow is no good. Period. End of story!

That is to say, calibrated monitor is a MUST workflow.

[station_two]

CaramelMacchiato wrote:

Agreed!

When working with certain photo editing, when using ProPhoto RGB workflow, it is wise to use a calibrated monitor…

"Wise"?  It is absolutely essential! 

[Chris Cox]

Can we please calm down and avoid personal insults here?

This topic has gotten several moderation requests today. And really, my idea of an enjoyable weekend does not include editing other people's personal attacks.

Look, not everyone gets color management.  There are some new concepts to learn, and unfortunately there is a lot of bad information out there that sometimes has to be unlearned.  It's going to take some time, and probably more than a few analogies and examples, to anwer the questions.  Just take the time, and answer the questions. If they don't get it, try another approach.

OK?

[station_two]

Fully understood and much appreciated.

There's a slight possibility that the thread with the several moderation requests is another one, but your admonition is welcome and will be applied to both threads—and to any other thread, for that matter.

[Chris Cox]

I'm still trying to work on the other one.

[Noel Carboni]

Chris Cox wrote:

unfortunately there is a lot of bad information out there that sometimes has to be unlearned.

Amen, brother. 

For some reason this is a subject that everyone, at every level of understanding, seems to want to give advice about.  I've cringed more than once when watching video tutorials and seeing people say "just do it this way" - implying the viewer's needs are exactly what the presenters needs are.

I'd like to reiterate one thing:  All of the settings and choices - every single one - has a need for being there.  That implies that there's no one "set it and forget it", "right way" to do things.  It's probably not even possible to nail down a one "best way" to do things, because the assumptions and givens from one day might differ on the next.

The only true path to success - to being able to make the right choices for a particular situation - seems to be to try to gain a full understanding of HOW it all works, not only including theory but actual implementation by various systems.  Then the choices start to make sense.  Trouble is, it's the kind of subject where when someone finds, by a little understanding or by accident, a way to get good results they tend to want to stop the pain of learning more at that point.

I've often wondered whether it's necessary to be a software engineer and actually implement working color-management software before you can fully get your mind around color-management.

-Noel

[Lundberg02]

I wish pf22 would chime in on this thread. He does the best sRGB to print I've ever seen.

[trying_to_explain]

Trouble is, it's the kind of subject where when someone finds, by a little understanding or by accident, a way to get good results they tend to want to stop the pain of learning more at that point.

Don't you find that applies to most subjects in life?

When you're a kid you think you know everything, it's only when you start to get a better understanding of something that you realise the topic gets deeper... and deeper... and deeper...

At some point you have to decide where to stop. There's no way you can know everything about everything, you just need to pick a personal compromise point and leave it there. Until you want to know some more...

[Noel Carboni]

trying to explain wrote:

Don't you find that applies to most subjects in life?

For me personally the desire to learn doesn't stop, just my ability to learn is the limiting factor.  And of course as we advance in years some of what we've learned, sadly, starts to go away, especially if we don't use it regularly.

Color-management seems a particular challenge, because the more you know, the less apt you are to say there is a "right answer".  Yet as humans we always tend to try to oversimplify the world so as to just be able to deal with it.  Extreme oversimplification leads to an answer.  Whether it's "right"...

Color-management defies oversimplification.  Some choices beget other choices.  For example, the specific monitor you buy can indirectly affect your choices for working space, even though it seems that it shouldn't.  Even the specific settings you choose to use on the monitor might factor in.  Manufacturers of high-end models often offer an "sRGB Gamut Emulation" mode, for example.  There are reasons some folks would want to use that, intentionally limiting the monitor's gamut.

And of course the work products matter... A web designer who does occasional photo prints on an inexpensive inkjet will almost certainly choose settings differently than a person who prints fine art on an expensive wide gamut printer.

Thing is, one can make decent looking prints no matter what color space one chooses to work in.  Most pixels in real, every day images don't exceed even the gamuts of the smallest color spaces.  But, for those who want to produce exceptional work products, the choices are there, and the equipment is there to do even more.  I happened to be in a gift shop yesterday where a local photographer had several prints in frames in a glass cabinet.  The images were of colorful local birds.  What was special was that the lighting was set up nicely, and the prints had vibrant colors that really seemed to jump off the textured paper, especially the oranges and golds.  She had clearly made color-management choices that allowed her to achieve printed results that were noticeably a cut above pretty much everything else you see printed.  I bet she sells those prints.

-Noel

[NB, colourmanagement net]

Hey Lundberg02,

I'd like to add that if moving (converting)  from ProPhoto to any smaller RGB colorspace then there is a very serious danger of clipping, despite what Photoshop may offer - that conversion is always Colorimetric.

Photoshop's workingspaces do not include a perceptual tag. [and ebven if they did see Thomas Knolls* comments below]

Thomas Knoll — Photoshop Hall of Famehttp://www.photoshophalloffame.com › bert-monroy-1

If s/he's converting from ProPhoto to  a CMYK colorspace because the printer told them specisifally what colorspace to use then there is less risk of clipping but it can still happen, even Perceptual can clip.

Photoshop's father, Thomas Knoll, wrote to me in 2001:

Neil,

You seem to have discovered how much of a kludge "perceptual" rendering really is with the current ICC profile model.

The standard description of perceptual intent: "smoothly compresses the entire gamut of the source profile into the gamut output profile without clipping" is absolute b***s***.  It does not work this way. It is impossible to make it work this way with the current ICC profile model.

The basic problem is that source profile and the destination profile are completely independent.  All the source profile does is tell the CMM how to convert source device colors to the PCS space (basically Lab space).  The source profile has no idea what the destination profile is going to be.  All the destination profile does is tell the CMM how to convert colors in the PCS space to device colors.  The destination profile has no idea what the source profile was.

So how is perceptual intent *really* implemented?  

Answer: the author of the profile building tool makes some wild guess of a "typical" source gamut, and builds some fixed desaturation and darkening (of high saturation colors) into the destination profile.  Because the author wants the resulting profiles to work well for a wide range of source images (including images already mostly in gamut), the fixed gamut compression is usually limited to only minor amounts.  In any case, *huge* amounts of the PCS space are still clipped by the destination profile.

And no, the CMM does not "handle it".  I don't know of any CMMs on the market that perform any smart gamut mapping.  All of them just use the look up tables built into profiles to convert from source to PCS and from PCS to destination.  The only non-standard CMM processing in common use the Adobe's "black point compensation", which is more tone mapping rather than gamut mapping.

Thomas Knoll.

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colorsync-users mailing list

I hope that clarifies somewhat

neil barstow, colourmanagement net :: adobe forum volunteer
google me "neil barstow colourmanagement" for lots of free articles on colour management
[please only use the blue reply button at the top of the page, this maintains the original thread title and chronological order of posts]

[physics52]

Tom, I was wondering precisely the same thing. You can really understand things thoroughtly and explain it to a six year old. Or you can understand it like a six year old, repeat it, and hope it is right. I am the latter. Here is my guess: A color-managed application like Lightroom that always uses the ProPhoto color space (wide) for working,  displays in a natural-looking way as possible on a real monitor (AdobeRGB or sRGB) by mapping the colors onto the monitor's profile (calibrated or default profile), with knowledge of the range of colors it is mapping from and the range of colors it is mapping to, allowing for a proper mapping. The accuracy of editing the photos will depend on the color gamut of that monitor, and you might be editing colors that you can't see.  If your printer has a wider gamut than your monitor (most do) then you might not get "what you see is what you get" if you print directly from the raw preview.  On the other hand, if you export into a viewable color space, say with a jpeg (into sRGB or AdobeRGB, depending on your monitor), and print the resulting export while viewing on a calibrated monitor, then you are more likely to get "what you see is what you get."

[D Fosse]

You've picked up an 8 year old thread, but of course the question is still valid and relevant.

The short answer is that the importance of choosing a color space is vastly overrated. You can do great work in any color space. What's overlooked are the dangers of moving from one color space to another. That's when all the problems happen.

You always need to consider where the image is coming from, and where it's going. And that's where most people get in trouble with ProPhoto, because they fail to realize you have an elephant that sooner or later you need to push through a narrow door. If you're not careful, you may end up with a severely clipped result and/or serious artifacts, and that never looks good.

In short, working in ProPhoto is a lot of work. Most of the time it's not worth it.

Often the premise of this whole discussion seems to be "bigger is better", and so you have this notion that ProPhoto is "best". But good color is not about maximum saturation, it's about color relationships. The question should be, is it useful. The large gamut has a price.

Here's one use case: when processing raw files, you often get areas of intense saturation that are simply artifacts of the sensor technology and/or processing. They may not be "real" and often they need to be controlled. But until you can do that, you may need to contain them without clipping. So you can open in ProPhoto until you decide what to do.

[Conrad C]

---

@physics52 wrote:

…The accuracy of editing the photos will depend on the color gamut of that monitor, and you might be editing colors that you can't see.  If your printer has a wider gamut than your monitor (most do) then you might not get "what you see is what you get" if you print directly from the raw preview.  On the other hand, if you export into a viewable color space, say with a jpeg (into sRGB or AdobeRGB, depending on your monitor), and print the resulting export while viewing on a calibrated monitor, then you are more likely to get "what you see is what you get."

---

One trap to look out for is thinking only in terms of “bigger” or “smaller” gamuts, because any gamut based on a device is not a perfect sphere or cube, but an irregular shape. When you compare two gamuts, usually each is bigger than the other in different places…neither is a clear winner. Because of this, you don’t necessarily get better “what you see is what you get” (WYSIWYG) by proofing a print in Adobe RGB vs sRGB. What is important is how well the gamut you use is matched up with the color limitations of the specific printer/paper/ink combination. The way you get the best possible print preview, on a display of any gamut, is to display the image corrected for both the profile of a calibrated display and the profile of the printing conditions: soft-proofing. In other words, an image viewed in an accurate soft-proof mode on a calibrated sRGB display can be a more useful print preview than the same image displayed (without soft-proofing) straight to a calibrated Adobe RGB display. When you use a display with a larger gamut, what that gets you is not necessarily more accuracy for print, but the potential to soft-proof more (though maybe still not all) of the printable colors. 

Some still say larger gamuts like ProPhoto RGB are unnecessary because you can't see or print all the colors in them. But that includes a mistaken assumption that sRGB or Adobe RGB reproduces all the colors you can print, which is also not true. If you are printing, reproducing more printable colors is an argument to use a larger gamut such as Adobe RGB. Although even Adobe RGB can’t print all of the colors that a current pro-level printer can.

Over the past 25 years, pro photo printers have been able to reproduce more and more colors outside sRGB. If I had chosen to limit editing to sRGB since I started doing this in the 1990s, images I edited all those years would be missing out on improvements in printed color reproduction. Images edited years ago in larger gamuts on a wide gamut display can now be opened and remastered for a better print on a new expanded gamut printer. Maybe I couldn’t see all the colors in the file then, but with today’s equipment I can see more of them, and a few years from now, maybe even more colors than today. So why limit?

To be sure, it isn’t necessarily any kind of an “art crime” to do everything in sRGB. Most of the time, viewers are not going to notice, except maybe if you show them properly edited sRGB and larger gamut copies of the same image side by side. If you don’t tell anyone everything is sRGB and you mount a major exhibition, chances are nobody will ever think to question whether they were all sRGB, unless the images are so saturated that color detail at the extremes is visibly flattened out of existence by sRGB. If you do great work in sRGB and are happy with that, you don’t necessarily have to listen to anyone’s dogma about wider gamuts.

But part of the reason digital photo equipment is so expensive is the astounding range of tones and colors they can reproduce, so it seems like kind of a waste of money to buy all this very capable gear and then throw out all the colors outside sRGB or Adobe RGB.

My own choice is to edit in ProPhoto RGB, but if someone else has concerns about the challenges of working in it, I think it’s fine to work in Adobe RGB or even sRGB as long as you understand the tradeoffs. Beyond Adobe RGB you do get into diminishing returns; the further out you get into ProPhoto RGB the fewer of those extended colors your photos actually contain. But sRGB seems to be too limiting of a compromise.

[physics52]

Good point about the soft proofing when using an .icc. Because of the diminishing returns outside of AdobeRGB, I guess I'd be inclined to do the final soft-proofing in AdobeRGB color space on a calibrated, AdobeRGB-capable monitor. Thanks.