Luminous Landscape Forum

Raw & Post Processing, Printing => Adobe Lightroom Q&A => Topic started by: John McDermott on December 08, 2007, 01:42:49 pm

Title: What workspace profile?
Post by: John McDermott on December 08, 2007, 01:42:49 pm
This question is aimed primarily at Jeff Schewe. I have bought and watched both your LR and C2P tutorials in which you recommend using Prophoto as the working space profile (Ialso bought your Camera Raw & CS3" book but just received it today so haven't had the time to read it yet). However, I am also a customer of Cathy's Profiles and in her latest documentation she makes the following recommendation:

"When the image color space is ProPhoto RGB it is much larger than the printer color space. The profile must compress the image color space into the much smaller printer color space and this may cause poor quality prints unless you have expert editing skills. It is much easier to achieve excellent results when the image color space is approximately the same size as the printer color. These types of problems are not a reflection on the quality of the profile but instead reflect on the ability of the person using the profile."

The result of her argument is to use Adibe RGB (1998) instead.

I'm not smart enought to evaluate the validity of her argument so I thought I'd ask for your opinion. Obviously you prefer ProPhoto RGB, but please elaborate on your reasoning.
Title: What workspace profile?
Post by: David White on December 08, 2007, 05:01:32 pm
I'm not Jeff and there are several facets to your question that need answering.  The only one I will address is the misstatement about having to compress the image to fit it into the printer's color space if ProPhoto is your working space.  

The profiles I made for my Canon IPF5000 easily exceed the gamut of Adobe RGB in several areas of the color space.  By not using ProPhoto I would be throwing away the extra image gamut available outside of Adobe RGB from my printer.
Title: What workspace profile?
Post by: digitaldog on December 08, 2007, 05:45:14 pm
http://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf (http://www.adobe.com/digitalimag/pdfs/phscs2ip_colspace.pdf)

Gamut mismatch (fitting round pegs in square holes):

There are way, way more colors that can be defined in something like ProPhoto RGB than you could possibly output, true. But we have to live with a disconnect between the simple shapes of RGB working space and the vastly more complex shapes of output color spaces to the point we're trying to fit round pegs in square holes. To do this, you need a much larger square hole. Simple matrix profiles of RGB working spaces when plotted 3 dimensionally illustrate that they reach their maximum saturation at high luminance levels. The opposite is seen with print (output) color spaces. Printers produce color by adding ink or some colorant, working space profiles are based on building more saturation by adding more light due to the differences in subtractive and additive color models. To counter this, you need a really big RGB working space like ProPhoto RGB again due to the simple size and to fit the round peg in the bigger square hole. Their shapes are simple and predictable. Then there is the issue of very dark colors of intense saturation which do occur in nature and we can capture with many devices. Many of these colors fall outside Adobe RGB (1998) and when you encode into such a space, you clip the colors to the degree that smooth gradations become solid blobs in print, again due to the dissimilar shapes and differences in how the two spaces relate to luminance.
Title: What workspace profile?
Post by: Schewe on December 08, 2007, 05:53:41 pm
Quote
"When the image color space is ProPhoto RGB it is much larger than the printer color space. The profile must compress the image color space into the much smaller printer color space and this may cause poor quality prints unless you have expert editing skills. It is much easier to achieve excellent results when the image color space is approximately the same size as the printer color."
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Well, the above quote is simply wrong...nothing about printing is "EASY" and trying to make people think a smaller working space will make anything easier is naive at best and disingenuous at worst.  

The "size" of the working space is not really an active factor when determining the "skill level" required on the part of the user. Yes, ProPhoto RGB is a really, really big space. I use it to make sure colors that my camera can capture and colors that my printer can print don't get clipped by a smaller working space.

As gvdavewh says, there's a lot of color that _CAN_ be printed on today's high-end pigment printers that can't be contained in Adobe RGB. So, working in Adobe RGB not only clips colors your camera is capturing but that can be printed.

As long as you have an accurate display profile and an accurate printer profile, there's no particular GREATER difficulty using ProPhoto RGB than any other working space and several benefits.

But the choice of working space is really something people need to determine themselves...listening to ANYBODY else is really avoiding the issue by avoiding doing the testing and making a determination, based on the results, for oneself...if you want to make maximum use of the camera colors and the printer colors, as I do, then there's really only one choice of working space. If those issues aren't important–and only YOU can determine that–then use the space that works the best for you.
Title: What workspace profile?
Post by: John McDermott on December 08, 2007, 08:06:25 pm
 Thank you Jeff (and others) for explaining and clarifying that for me. When I saw the quote on Cathy's Profiles it surprised me as I had never heard that before. I can now file it under "old wive's tales".
Title: What workspace profile?
Post by: digitaldog on December 08, 2007, 09:39:31 pm
Quote
When I saw the quote on Cathy's Profiles it surprised me as I had never heard that before. I can now file it under "old wive's tales".
[a href=\"index.php?act=findpost&pid=159347\"][{POST_SNAPBACK}][/a]

Cathy may have the mechanics of building profile down but she's pretty confused about their use and role in the entire color management workflow.
Title: What workspace profile?
Post by: Hendrik on December 10, 2007, 06:58:02 am
In LR the standard color spaces are ProPhoto RGB, Adobe RGB and sRGB. Most, if not all photographers never need anything else. Today the fashion is to use ProPhoto RGB as your standard color working space. Most of the times, with the use of 16-bit images, it’s a safe color space.

… but knowledge about color management is vital and not all recognize problems when they encounter them. It’s my opinion ProPhoto RGB is NOT recommended when people know nothing about the basics behind all this. Selecting a small color space like sRGB can result in loss of saturated color and loss of detail when clipping is significant. Fortunately many images don’t benefit from a wide gamut color space, because it never contained any colors outside sRGB to begin with.

I mostly work in a studio environment and my subjects are models. Skin tones are important and fall easily inside the sRGB container. When the background, make-up or clothing contains colors outside sRGB, I can benefit from a wider color space like ProPhoto RGB. I have to do this with caution; because I sometime notice that my skin tones fall apart when I need to edit them, even with 16-bit images. I choose sRGB in LR instead and sacrifice some colors outside sRGB, but got better skin tones.

Bottom line is that I think the image data is the determining factor when selecting a working color space. Do you need ProPhoto RGB? If your answer is no, a smaller color space is all you need and in my opinion is the better choice.

[span style=\'font-size:8pt;line-height:100%\']I most often use ProPhoto RGB, I regulary use sRGB and seldom use Adobe RGB (all 16-bit)[/span]
Title: What workspace profile?
Post by: billg71 on December 13, 2007, 10:07:43 pm
I used to do most of my work in Nikon's Capture NX using aRGB space as the default color space and often had horrible problems with out-of-gamut areas on my prints.

Now I have NX, LR and CS3 all set to ProPhoto and haven't had the out-of-gamut blobs and blotches. Yet....

Just my $.02/worth, YMMV.

Bill
Title: What workspace profile?
Post by: genemcc on December 13, 2007, 11:07:09 pm
The concept of using larger color spaces just make sense.  It is easier (and I use that term relatively, Jeff   ) to work your way down to the printer's space than it is to just lop off color info by starting in a color space that is smaller than what your camera sees.  When you start there you've already lost some of the artistic and critical control.

Jeff is correct in that printing is not easy.  So why make it harder by tying some pixels behind your back at the start?  
Title: What workspace profile?
Post by: billg71 on December 14, 2007, 12:14:04 am
Quote
The concept of using larger color spaces just make sense.  It is easier (and I use that term relatively, Jeff   ) to work your way down to the printer's space than it is to just lop off color info by starting in a color space that is smaller than what your camera sees.  When you start there you've already lost some of the artistic and critical control.

Jeff is correct in that printing is not easy.  So why make it harder by tying some pixels behind your back at the start? 
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Good point, Gene. I think of it as limiting precision, for example, setting up an Excel spreadsheet and limiting it to 2 decimal places of precision. The first 4 or 5 calculations, it won't make a difference. After a few million iterations, it's more than likely the output will differ significantly. Banks and credit card companies make millions every year on small fractions of a decimal point. Who knows how many calculations are run on an image when you sharpen, reduce noise, crop, adjust levels, etc. in any editing program?

Manipulating data at the highest precision possible is a no-brainer. No matter what you do to it, you'll always end up with the result that most closely matches the input. The final step is to reduce that result to a usable number, that's where you do all the rounding. Whether it's to display as two decimal points in a spreadsheet or to send to a printer, you'll always get the most accurate results by maintaining the highest precision possible throughout the process.

In photo terms, you start with the widest range of data available, maintain that range throughout the editing process and then reduce the final output to something the export device is capable of handling. Doing anything less is literally throwing away data you worked hard to capture in the first place.

Bill
Title: What workspace profile?
Post by: Hendrik on December 14, 2007, 05:26:59 am
There are two aspects competing with each other and using the largest color space is not giving you the highest precision.

The smallest color space will give you the highest precision of color manipulation. The data points (colors) are closest to each other in the smallest color space. ProPhoto RGB will give you a larger color gamut, but the data points are also wider apart. With 16-bit channels its most of the time not a big problem and one can safely use this as a standard color space so long you keep an eye on (rare) problems. As I said in my earlier post, sometimes even 16-bit colors can be insufficient (in a large color space) and manipulating these delicate colors can give banding.

Highest precicion: 16-bit channels and sRGB color space.
Lowest precicion: 8-bit channels and ProPhoto RGB color space.
Title: What workspace profile?
Post by: digitaldog on December 14, 2007, 09:22:30 am
Quote
There are two aspects competing with each other and using the largest color space is not giving you the highest precision.

The smallest color space will give you the highest precision of color manipulation.
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That is true. The colorimetric differences between two 'adjacent' colors if you will have a higher deltaE in a larger than smaller color space. Just another reason why as the spaces get larger, you really DO want to be working in a higher bit depth.

This is really more an issue for displaying the data these days, far less so for editing (the majority that should be done in the Raw converter, linear high bit wide gamut). If you're working on very subtle colors in an image, its going to be much harder to see them on a wide gamut display than an sRGB like device.
Title: What workspace profile?
Post by: kers on December 14, 2007, 11:07:26 am
In line with I guess it would not make sense to work in a Prophoto space with 8 bit colors and it does make sense for skin tones to use sRGB with 16 bit colors...

I already notice working in Photoshop with curves that when I use the Prophoto space subtle color correction becomes more difficult than when I use the sRGB space
Title: What workspace profile?
Post by: woffles on December 28, 2007, 12:51:45 am
I have to ask a question here.  On my cameras the color space is set to Adobe RGB.  I shoot all in RAW.  Am I capturing in Adobe and then opening in ProPhoto in LR?  Is it just a waste of extra color space then?  Am I creating new colors when I edit?
Title: What workspace profile?
Post by: TMcCulley on December 28, 2007, 01:19:46 am
Quote
There are two aspects competing with each other and using the largest color space is not giving you the highest precision.

The smallest color space will give you the highest precision of color manipulation. The data points (colors) are closest to each other in the smallest color space. ProPhoto RGB will give you a larger color gamut, but the data points are also wider apart. With 16-bit channels its most of the time not a big problem and one can safely use this as a standard color space so long you keep an eye on (rare) problems. As I said in my earlier post, sometimes even 16-bit colors can be insufficient (in a large color space) and manipulating these delicate colors can give banding.

Highest precicion: 16-bit channels and sRGB color space.
Lowest precicion: 8-bit channels and ProPhoto RGB color space.
[a href=\"index.php?act=findpost&pid=160646\"][{POST_SNAPBACK}][/a]

Quote
That is true. The colorimetric differences between two 'adjacent' colors if you will have a higher deltaE in a larger than smaller color space. Just another reason why as the spaces get larger, you really DO want to be working in a higher bit depth.

This is really more an issue for displaying the data these days, far less so for editing (the majority that should be done in the Raw converter, linear high bit wide gamut). If you're working on very subtle colors in an image, its going to be much harder to see them on a wide gamut display than an sRGB like device.
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Hendrick and Andrew,

Please I am confused by the use of the term "precision".  I cannot believe that using a sRGB colorspace would lead to more precision just less choice so easier decisions.  What did I miss?

Tom
Title: What workspace profile?
Post by: John.Murray on December 28, 2007, 01:19:58 am
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I have to ask a question here.  On my cameras the color space is set to Adobe RGB.  I shoot all in RAW.  Am I capturing in Adobe and then opening in ProPhoto in LR?  Is it just a waste of extra color space then?  Am I creating new colors when I edit?
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The Adobe RGB colorspace only applies to jpeg images produced by the camera.  

hth - John
Title: What workspace profile?
Post by: method on December 28, 2007, 02:28:07 am
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On my cameras the color space is set to Adobe RGB.  I shoot all in RAW.  Am I capturing in Adobe and then opening in ProPhoto in LR?  Is it just a waste of extra color space then?  Am I creating new colors when I edit?
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You assign the working space in the software at conversion time. It is one of the the great advantage of RAW!

Richard Earney

--
[a href=\"http://inside-lightroom.com]http://inside-lightroom.com[/url]
Title: What workspace profile?
Post by: Hendrik on December 28, 2007, 06:07:32 am
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Hendrick and Andrew,

Please I am confused by the use of the term "precision".  I cannot believe that using a sRGB colorspace would lead to more precision just less choice so easier decisions.  What did I miss?

Tom
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I will use an analogy of a stair.

The height of the stair determines the color gamut. If you go higher, the colors will become more saturated.

ProPhoto RGB is a very high stair, you reach a high altitude with it. With 8-bit, you only have 255 steps to reach the upper part of ProPhoto RGB.

sRGB is not so high compared to ProPhoto RGB, in a matter of fact, it’s a very low stair. To reach the upper part of this low sRGB stair, you also have 255 steps. Because the stairs have a different height, but the same amount of steps, the steps of the sRGB stair must be much closer spaced compared to the ProPhoto RGB stair.

This is the reason you have finer control in a smaller color space. The colors are closer to each other.
Title: What workspace profile?
Post by: digitaldog on December 28, 2007, 10:08:52 am
Quote
I have to ask a question here.  On my cameras the color space is set to Adobe RGB.  I shoot all in RAW.  Am I capturing in Adobe and then opening in ProPhoto in LR?  Is it just a waste of extra color space then?  Am I creating new colors when I edit?
[a href=\"index.php?act=findpost&pid=163528\"][{POST_SNAPBACK}][/a]

Raw has no color space. And it doesn't matter what you set your camera to (you're shooting Raw).

In a modern Raw workflow, I don't see the need for Adobe RGB (1998) at all. I encode in ProPhoto since its the widest color space I have available in my converter, this converter is using the ProPhoto primaries anyway after the Raw goes through its demosaicing, and lots of images and some output devices exceed Adobe RGB (1998). So, its Raw in, ProPhoto RGB in 16-bit out.
Title: What workspace profile?
Post by: TMcCulley on December 29, 2007, 02:00:23 am
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I will use an analogy of a stair.

This is the reason you have finer control in a smaller color space. The colors are closer to each other.
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So if I created a monochrome gradient in 8bit RGB with sRGB it would be smooth while the same gradient with ProPhoto would be banded?  This problem would simply go away by switching to 16bit RGB

Why are we doing 8bit for anything other than web display anyway?

Tom
Title: What workspace profile?
Post by: Hendrik on December 29, 2007, 05:15:21 am
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So if I created a monochrome gradient in 8bit RGB with sRGB it would be smooth while the same gradient with ProPhoto would be banded?  This problem would simply go away by switching to 16bit RGB

The steps with 8-bit in ProPhoto RGB are very large, it’s a recipe for creating an image wreck, especially if you try to pull or compress the tones. I never tried to make a gradient in ProPhoto RGB and 8-bit though.   Switching from an 8-bit to 16-bit image will not give you any benefits, but selecting 16-bit in the RAW converter will preserve the 12-bit data from the original RAW file.

Quote
Why are we doing 8bit for anything other than web display anyway?

I don’t know, I always use 16-bit. Maybe diskspace?  
Title: What workspace profile?
Post by: bjanes on December 29, 2007, 02:28:59 pm
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Raw has no color space. And it doesn't matter what you set your camera to (you're shooting Raw).

In a modern Raw workflow, I don't see the need for Adobe RGB (1998) at all. I encode in ProPhoto since its the widest color space I have available in my converter, this converter is using the ProPhoto primaries anyway after the Raw goes through its demosaicing, and lots of images and some output devices exceed Adobe RGB (1998). So, its Raw in, ProPhoto RGB in 16-bit out.
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Here we go again:

[a href=\"http://luminous-landscape.com/forum/index.php?showtopic=21046&view=findpost&p=154947]Camera Color Space[/url]
Title: What workspace profile?
Post by: woffles on December 30, 2007, 02:38:15 am
Quote
Here we go again:

Camera Color Space (http://luminous-landscape.com/forum/index.php?showtopic=21046&view=findpost&p=154947)
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Just trying to read some of that was painful.  So basically, RAW doesn't have a "standard" assigned color space, a camera has a native color space which consists of the gamut or range of colors that it can capture, if you even call them colors.  But, then,  greyscale or black and white are colors!  My only question is, is that gamut larger then Adobe RGB then?  I'm assuming it is otherwise ProPhoto would be kind of useless in LR, wouldn't it?
Title: What workspace profile?
Post by: digitaldog on December 30, 2007, 10:25:23 am
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My only question is, is that gamut larger then Adobe RGB then?  I'm assuming it is otherwise ProPhoto would be kind of useless in LR, wouldn't it?
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There's the scene gamut as well as the capture device "gamut" (quotes because digital cameras don't have a color gamut).

Bottom line is, you can shoot all kinds of scenes of wide gamut that exceed Adobe RGB (1998) and if you use that as an encoding color space from your Raw converter, you're not realizing (using) all the colors at the scene or that the capture device was capable of capturing.
Title: What workspace profile?
Post by: john545 on January 11, 2008, 02:25:28 pm
Quote
Raw has no color space. And it doesn't matter what you set your camera to (you're shooting Raw).

In a modern Raw workflow, I don't see the need for Adobe RGB (1998) at all. I encode in ProPhoto since its the widest color space I have available in my converter, this converter is using the ProPhoto primaries anyway after the Raw goes through its demosaicing, and lots of images and some output devices exceed Adobe RGB (1998). So, its Raw in, ProPhoto RGB in 16-bit out.
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Hi,

I'm new to color management, so apologies if my questions or assumptions might appear ignorant, as that is exactly what they are.  

Given that I am at the beginning of my 'color management research', I have many questions, but in the spirit of not wearing out my welcome, I'll limit myself to just a few. I use Lightroom and CS2. I have attempted to calibrate my monitor with i1D2 (with mixed results...automatic doesn't seem to be that much different that my original display, manual with ambient light calibration makes the display much, much lighter, and I have to have a flourescent lamp partially shining on the monitor to get an ambient reading within the suggested range...I've returned to the Auto profile):


1) When is a color space assigned to  an image?
       a] When the RAW file is imported into LR?
       b] When one 'edits a copy' in CS2?
       c] When the edited file is exported?

2) Where can I find a *simple* explanation on how to implement color management?

My initial confusion is based on how to assign the color spaces and profiles. I have a profile for my monitor, CS2 has several working spaces that I can choose from, from what I've read here, LR automatically uses Pro Photo. That's not counting the printing profile issues.

I'm confused on how to implement all of this so that I can get back to dealing with the images and start printing and have some assurance that my images will look reasonably OK on other displays. I'm not sure that I can gain a thourough understanding of all of this right now, but just to know how to set the color spaces and profiles up in the different apps and weather I would need to export my final version to whatever colorspace.

Also, can an image edited and assigned one color space be assigned another and be the same as if the changed color space was originally implemented?

Again, my apologies if this post is somewhat convoluted, as I'm pressed for time right now (as usual). Any guidance that anyone can provide is greatly appreciated.

Thank you!

John545
Title: What workspace profile?
Post by: Schewe on January 11, 2008, 04:22:27 pm
Quote
1) When is a color space assigned to  an image?
       a] When the RAW file is imported into LR?
       b] When one 'edits a copy' in CS2?
       c] When the edited file is exported?
[a href=\"index.php?act=findpost&pid=166564\"][{POST_SNAPBACK}][/a]


You would be better served starting a new thread asking these questions rather than piling it on this one.

In answer to #1, if raw, no color space is assigned until the image is processed into something other than the preview on screen. The preview on screen _IS_ processed by the Camera Raw pipeline based upon the raw rendering + parameter settings but it's not "baked" until you actually process.

If the original is not raw, then whatever embedded profile is in the file is assumed. If no profile is embedded, sRGB is assumed by Lightroom & Camera Raw.

As to what color space _WILL_ be in the image after processing, that depends on the selected color space in CR/LR. But Lightroom only has the three choices, sRGB, Adobe RGB and ProPhoto RGB.
Title: What workspace profile?
Post by: john545 on January 13, 2008, 03:26:49 pm
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You would be better served starting a new thread asking these questions rather than piling it on this one.

In answer to #1, if raw, no color space is assigned until the image is processed into something other than the preview on screen. The preview on screen _IS_ processed by the Camera Raw pipeline based upon the raw rendering + parameter settings but it's not "baked" until you actually process.

If the original is not raw, then whatever embedded profile is in the file is assumed. If no profile is embedded, sRGB is assumed by Lightroom & Camera Raw.

As to what color space _WILL_ be in the image after processing, that depends on the selected color space in CR/LR. But Lightroom only has the three choices, sRGB, Adobe RGB and ProPhoto RGB.
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Hi, and thanks for the response to my quesitons. Your comment regarding the new thread is well taken.

Thanks!