ACR and LAB Color

Hi, all -
Earlier this year, I was reading Dan Margulis' book on LAB color, and one day when I was making some adjustments in ACR, it dawned on me that the white balance slider is the same (blue => yellow) as the "b" channel in LAB and that the tint slider (green => magenta) is the same as the "a" channel. That got me thinking (too much time on my hands, I guess!)... Is there any correlation between how those sliders work and the LAB colorspace (in other words, are those adjustments in ACR being made using the LAB colorspace, even if the image is in RBG)? Then, I thought some more... and realized that the exposure, recovery, blacks, fill light, brightness, and clarity sliders all seem as though they'd affect only the "L" channel in LAB, which made me wonder even more.
There was no mention of ACR in the book I was reading, and I have not read any of the Real World Camera Raw books (waiting for the latest to come out so I can ask Santa to bring it). Is this just a wild coincidence, or are the ACR adjustments based on the LAB colorspace or color theory?
Thanks!

>the white balance slider is the same (blue => yellow) as the "b" channel in LAB and that the tint slider (green => magenta) is the same as the "a" channel.
Actually no...it's NOT the same. Lab does not use the Kelvin scale to describe the ab channels. Kelvin is based upon a blackbody radiation and is actually blue/amber and the magenta/green is perpendicular to that axis, which is NOT the same as the ab channels in Lab.
Camera Raw uses the Pro Photo RGB chromaticities in linear gamma for its internal color space and while a large set of functions are luminance only, it does that and the HSL corrections based on HSL which also is not the same as Lab.

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PSE and LAB color mode

I use PSE8 to design textiles. Normally my images are put into Index Mode and I specify colors from a LAB color catalogue and send the color specification in an e-mail or Excel file. My printer has asked that I specify the colors directly into LAB mode without indexing. Is there a plug in to do that? Thank You.

LAB is disabled at a pretty deep level in PSE. There are a few plug-ins that will let you simulate the effect you'd get with LAB (one of the settings in the smart curves plugin, for example), but nothing can add the ability truly to understand/render this color space, I'm afraid.

Color shift between image viewed in ACR and open in PS

Today I updated Photoshop CC and now I have a slight color shift problem between the same image open in ACR and then opened in Photoshop. It appears to be slightly more saturated in ACR.
I have tried the same thing on another computer and it does NOT have the same problem so it must have been something that happened in the update (ACR was one of the items updated). I have also compared the preferences between the two computers and they are identical.
I guess the next thing to do is to deinstall PS and reinstall????
Any advice would be appreciated.

Any difference between ACR and Photoshop is most likely due to a monitor profile problem. They both use the same monitor profile, but there are differences in the actual conversion so a problem can show up differently between them.
Is your monitor calibrated/profiled, and if so how, using what calibrator? Or are you using the Windows default (sRGB), or perhaps you got a bad manufacturer profile through Windows Update? (yes, that happens frequently).
To find out if the monitor profile is indeed the problem, go to Control Panel > Color Management > Devices. Set sRGB IEC61966-2.1 as default profile (if it isn't already), then relaunch Photoshop/Bridge and see if the difference is still there. If your monitor is wide gamut, use Adobe RGB instead.
Note that this doesn't fix the problem as such, but if you don't have a calibrator sRGB will usually be close enough until you decide to get one.
If you do have and use a calibrator, make sure it is set to make v2 profiles, not v4, and matrix rather than LUT profiles.

Pros and Cons of working in LAB color mode

I like to use LAB as my color mode. Partially becasue I have a spectrophotmeter and can sample things; partially becasue it is the space which I am most familiar with.
If you pick up almost any ID instruction book, it says "ID has three color modes: RGB, CMYK, and LAB. We aren't going to talk about LAB." I assume that is at least partially due to legacy. However, is there something I am overlooking? Is there a danger to work working in LAB I haven't thought through?
Mostly my work is output to web or print - both desktop and offset - without spot colors.

MarieMeyer wrote:
I seems to me that if I specify colors in LAB and then output to sRGB or Adobe RGB the color is going to be the same - whereas if I had typed in RGB values it will not. (Realizing this is NOT some magic cure for monitors not being calibrated!)
Obviously ID isn't an image editing/generator program, but for brochures and thing I do apply flat areas of colors. If I type in a LAB color that is out of the gamut of the CMYK profile of the working space, I get an OOG warning and can dial it back. What I really like is the speed with which I can adjust the value of the color without changing the hue/chroma by adjusting just the L channel. It is sort of like creating tint swatches, only in reverse!
dylw, I take your point about the number of printers who aren't meticulous. But don't I have the same problem if I'm relying on a swatchbook that provides CMYK values but was printed on a differe paper at a different company than the one that I'm going to use?
When I was a student I used to worry about exact color matching and presume that it could be achieved. Now that I've been out here working in the real world for a few years I understand that perfect color matching, even with good color management, is a myth. Most users don't have calibrated monitors, or even monitors capable of displaying the full gamut of what your eye can see or even what your camera or scanner might be able to capture, and process color gamuts are genereally smaller still. When you go to press you are at the mercy of the press operator, the vagaries of plate making equipment, paper inconsistencies, ink mixing, and even ink brand, not to mention the light sources in use at the press and in your office and where your product is finally viewed by your user, and how those particular inks react to differnt wavelengths.
Even a custom profile is at best a point sample, or an average of many point samples, from a particular run or runs, and is not going to match every sheet that comes off the press. A well-trained eye can probably spot variation in color from one end of a single press run to the other, and even more likely from one run to another. Your spectrophotometer is using a particular wavelength and angle of light to sample your color. Is that the same wavelength and angle that will be used in the client's office under the fluorescents? Has your specrophotmeter aged and drifted?
Color management is about getting good, or even excellent, matching of colors across various output conditions, but there are too many environmental variables to be able to achieve one single "perfect" set of output numbers. All you have to do is grab some output and stand in a doorway and compare what you see in daylight against what you see in room light to demonstrate. The human eye and brain, to varying degrees, recognize certain things as being "normal" colors and will accomodate to tell us, for example, that paper is white, even if it's a bit yellow or gray, until we have a whiter sample for comparison. Further, most of us are incapable of seeing the difference a 1 or 2% density shift on press would produce (and that's pretty close to the tolerance you could hope to achieve in the pressroom), let alone the fractions of percents that we often specify when converting colors.
Lab is a theoretical color space that has no "real world" equivalent, but is extremely useful for translating colors from one real world condition to another. Even if you choose to work "in" Lab, you are at best translating your sampled colors under their specific sampling conditions (which don't match your general lighting) to your monitor space (which may or may not be accurate) and then asking to translate to yet one more output space that probably will not match the real world conditions under which the finished work will be viewed.
What you are doing by specifying the color in Lab is trying to eliminate the source profile, but I doubt you'll get any better output.

Need lab color info in Camera Raw.

I would like to be able to see lab color info in addition to the RGB numbers in ACR. The ACR color correction sliders are lab in nature, and the lab numbers are easier for color correction than the RGB numbers.
I

Thanks for the reply. No, I don't have a painting background, so your comments concerning layered transitions are new to me, at least in the analytical.
I have a great deal of problems with color names. The huge array of oils, watercolors and such in an arts supply store with their fanciful names put me to rout! While I do explore the emotional side of camera work, knowing the numbers is equally important because of my long years in electrical engineering. I know, for instance, that the perception of a certain color is influenced by it's surrounds, sometimes profoundly. So, when I am looking at what appears to be a white reference, I want 120,120,120, or whatever the value is. I may not stay there, many times I don't but I know where things are headed.
I can't imagine that my D90 or D80, for that matter, cannot see aqua. That would mean all the cameras Nikon produces using the D90 sensor have this problem.
Did I see aqua? Back to nomenclature. What is aqua? Aqua means among other things water. Aquarius means water bearer.Here is one dictionary's set of definitions. Look at the Thesaurus. All those names are the same? Greenish blue is the same as bluish green?
http://www.thefreedictionary.com/aqua
I'll not likely ever be a painter. Painters, like musicians know these terms. Music is filled with them with plenty of overlaps. I can listen to a pice of music never heard before and get within one semitone of it on the piano first try. But I don't have perfect pitch. So I assume if I were to take up painting and devote the next 10,000 hrs or so to developing that skill, I may indeed recognize the subtle colors by name.
Aqua= greenish blue. Well, I thought cyan was greenish blue, but there is no equivalency between the two as applied in Photoshop.. For me anyway.
I've seen that blobiness myself, Tim. Next time I'll go deeper into it Thanks.
Jeff, if you are reading this and have gotten this far, let me say this about "experience" and "creditability" First off, you know I have experience in software testing. Never in my work did I ever have someone prove his point by pulling rank. Never. Software people get pretty deep into the subject. I am certain that TK and others worked HSL over quite thoroughly. The Orange and the Purple sliders do give me a freedom to finesse as never before, and I revel in it. But if your folks are anything like the people I worked with, someone winds up keeping them honest and away from wishful thinking, which gets more and more necessary with which to deal as release approaches. My job was, besides the technical validation work like smoke test etc, was to also inform them when the emperor is losing his clothes. What was nice about it is that we, the validation group, had the power to stop on a dime, and force a resolution. So I have no compunction in speaking up here.
Nor am I concerned about being vetted by you. It's not the first time I have been confronted by people here saying "Do you know who he is?" as if I should never dare to be so outspoken. My answer is yes, but do they know who I am?
One really can't know, and vetting all your responders takes way too much time and bandwidth. So, assume some experience and creditability is where the best in the world have always proceeded, like Einstein.
Lawrence

Blacked out images in Lab Color mode

This problem relates to Camera Raw 4.5 and 4.4.1. I first noticed this when I
opened a file in Lab color. When it opened the image went black. Also the top thumbnail in the channels panel was black. In RGB mode the top thumbnail
in the History panel is blacked out. This relates to my desktop,my laptop runs just fine with ACR 4.5. BTW my desktop is running XP Home,my laptop is running XP Pro. This seems like the right place to go for help. Oops,almost forgot... ACR 4.3.1 works fine,no problems at all.
Thanks,
Rich Kreidel

You really must get rid of any other copies of the Camera Raw plug-in, especially if the other copy is somewhere in the Adobe folder system. Try using the search feature on your menu, and search for camera raw.8bi and see if you can locate the other copy that way.
Another thing to check would be to open Photoshop and go to Help/About Plug-Ins. Camera Raw should only be listed once. If you see it listed multiple times then that is definitely your problem. Click on the Camera Raw listing(s) to find out what version you have.
This Camera Raw update/installation process has caused a lot of confusion for quite some time. Once you get to understand it, it really is a simple process to update. But all it takes is a little mistake to cause a lot of problems.

Acr and canon 70d

Hi,
i have just purchased a canon 70D camera and use lightroom 4 and elements 11 and neither of these support the camera for my raw files.
I much prefer to use ACR for my post editing and wondered if there will be an update in the very near future.I am not currently planning on upgrading to
lightroom 5 at this time.
Regards Adrian

Adobe needs to profile each camera’s raw sensor to convert raw to an image with the proper colors, and Adobe only updates their current version of software for new cameras.
If your camera-model is newer than your software version, then you’ll need to upgrade or update your software to a version that was released after the camera became available and Adobe added support, which includes the possibility of updating to the latest DNG Converter 8.2 once it is released (at the same time that ACR 8.2 and probably PSE12 are released), and converting your native-format raw files to DNG-format raw files that can be processed with older ACR and LR versions.
The issue, at the moment, is that the pre-released versions of ACR 8.2 RC and DNGC 8.2 RC from Adobe Labs pretend that the 70D raw files have camera profiles from the 6D so only the final versions of DNGC 8.2 and ACR 8.2 will have the new 70D camera profiles and the look of the images might change, slightly.
I prefer not to use DNG format for anything so I always update my LR and ACR to the latest version.

When I select the lab color mode, many options are greyed out?

Can anyone help me . When I select Lab color, many options are grey out. The following are greyed out: exposure,vibrance, black and white, channel mixer, and selective color. It worked perfectly the first time I used it but will not work now. Do I need to reset something. I have tried everything I can think of. I use a PC and PS 5.
Thanks for the help.

I'm working on the Mac versions of CC and CC 2014. If I select Lab, those very same options are grayed out.

Few Questions 'bout Printing in Lab Color

I'm a little confused about how LAB color works. I have a document thats currently in CYMK color mode, and I'm having difficulty finding satisfactory colors. I was advised elsewhere to abandon CYMK. I therefore want to convert my image into to LAB color mode. I've read that converting from one color mode to another can cause layers to look funny, however I need to retain some of my layers... Do you guys typically have problems with this? In retrospect I should have STARTED in Lab... Seems that converting from CYMK to LAB wouldn't be as problematic as converting from LAB to CYMK...
The key question is this: will my printer (Epson R800) even be able to print in LAB mode? I thought yes, or at least closely... because it has much more than CYMK to work with... it has these cartridges:
#1 Blue UltraChrome Hi-Gloss Ink Cartridge T054920
#2 Cyan UltraChrome Hi-Gloss Ink Cartridge T054220
#3 Gloss Optimizer UltraChrome Hi-Gloss Cartridge T054020
#4 Magenta UltraChrome Hi-Gloss Ink Cartridge T054320
#5 Matte Black UltraChrome Hi-Gloss Ink Cartridge T054820
#6 Photo Black UltraChrome Hi-Gloss Ink Cartridge T054120
#7 Red UltraChrome Hi-Gloss Ink Cartridge T054720
#8 Yellow UltraChrome Hi-Gloss Ink Cartridge
Finally, in the print screen menu should I be
"letting photoshop manage colors" or letting "printer manage colors"? Do you guys have any other tips on how to tweak printer/photoshop settings/preferences to maximize the accuracy of my colors? Would I possibly be better off just using RGB?
I know my questions are conveyed in a slightly confusing manner, so thank you for your patience reading through them. I really appreciate any insight you guys can give me.
Thanks,
Rich

You can't actually print in Lab mode, although it can be great for certain corrective moves. You have to print in either RGB or CMYK. If you are using the Epson driver for your printer, the print is seen as if it were an RGB device, even though it uses CcMmY and black inks.
To get better color accuracy, you need both a hardware calibrated monitor - so you know that what you see is accurate - and good custom printer profiles, so that the colors are properly converted to the color space of the printer. There is a lot of information both in these Adobe forums and on the web in general about color management and the proper use of profiles, and how to go about it.

Problems with CMYK/LAB colors

I'm independent and I send many print jobs to different print shops. I recently discovered to my horror that some color critical jobs have gone to press (to the same shop) with mismatched PMS colors. At first I blamed the print shop but they complained the CMYK values did not match. When I opened the two brochures in question, one had (for example) Pantone 288 C, color type spot, Color mode CMYK, 100/67/0/23 (dimmed because the colors came from an imported illustrator eps logo). The second (bad) brochure had the same color and color type, but in the mix it had Color Mode: Lab, L 8.039, a 8, b -50 - greyed out because again, the color came from the SAME eps file.
My next step was to remove the logo file from the bad Indesign doc. Then I doublechecked the color - success, the color now says color mode: Pantone solid coated, 288 C (which is from the built-in indesign swatch book). Then I brought BACK IN the logo file from the brochure that printed correctly. The color reverts back to LAB again!
When I import this same logo into a blank document, the colors are fine (CMYK with proper values).
I'd seen in other forums suggestions to check or uncheck "Use Standard Lab Values for Spots" in the Ink Manager, however both documents have this unchecked. (Adobe seems to encourage checking LAB but I've never done this, I'm afraid to start now as it will probably give my print shops fits.) And both have "convert spots to process" checked, which I always thought was the cure-all: shouldn't PMS 288 (CMYK) always be PMS 288 (CMYK), as long as both are converted to process? Why would one being a LAB and the other NOT being a LAB make them different? 288 should be 288....? (but I guess not....)
The good news is, the Zevrix extension "InPreFlight" will warn me if run on each document, so I don't have to drive myself crazy opening old files and doubleclicking every color. But I'm wondering what the heck is happening.
CLUE: I believe this all stemmed from a "brilliant" idea I had to shorten the list of color types to choose from by going into Indesign>Presets>Swatch Libraries and removing libraries I'd thought I wasn't using - I left all my Pantones, but I must have deleted an important one, because it was after I'd done this that I had noticed the Lab colors rearing their ugly heads. However it didn't occur to me that LAB (CMYK) would be different from regular CMYK since they have the same name. When I replaced this folder with one from another mac, viola, the problems stopped. However it doesn't stop the old, previously created files from continuing to open wrong and be printed wrong, if I don't catch them.
Any insight anyone could provide would prove most helpful. It would be nice to get a night's sleep for a change.....thanks!
FYI I'm using Indesign CS3 5.0.4 (recently updated) with Color Settings CMYK: U.S. Sheetfed Coated v2 and color management policies-preserve numbers (ignore linked profiles).

>one had (for example) Pantone 288 C, color type spot,
Mike, you are implying in your post that your jobs are being output as CMYK, but your colors are set as spots. If that's the case your printer is converting the spot colors to process CMYK, which would cause the problem you are describingPantone Solid colors are converted to CMYK via color management when Use Lab is checked. The resulting output values would depend on the document's destination CMYK profile.
If your job is indeed CMYK you should stop using the Pantone Solid library and use the Solid to Process library instead, which always output as Pantones CMYK builds.
Use Lab is useful when a job is to be output as Spot color because you will likely get a more accurate preview of the color and a better proof to a composite printer. Many Pantone colors are out of the CMYK gamut. Lab can also be useful if you are sending a job to CMYK and you want to color manage the conversion of a solid color to CMYK, rather than using Pantones built formulas which are device dependent.

Just installed mountain Lion. Viewing a pdf sent to me using preview and some colors are appearing BLACK, however when I view the same PDF in Acrobat they are perfect and what they are suppose to be. WHY would PREVIEW showing a different color?

Just installed mountain Lion. Viewing a pdf sent to me using preview and some colors are appearing BLACK, however when I view the same PDF in Acrobat they are perfect and what they are suppose to be. WHY would PREVIEW showing a different color?

Here's what I've found on the issue:
Pantone color definitions have changed (coinciding with CS6) — they are now "Pantone+" (I think that's what they're called). The "+" apparently means they're now LAB colors. Lab colors are not properly displayed in Preview (or in Finder previews) — they display as black (as far as I can tell, in all circumstances). I'm sure it's a tad more complicated than that, but that's the gist.
Now the bad news — nobody seems to know anything about a fix or workaround (unless you convert your PDFs to process — this might be a fix for sending to clients). It causes issues for me in AI files — being able to view them in the finder (with previews) is a HUGE time saver for my workflow... when they're all black, not so much.
In my chat with a director of product dev at Adobe, they placed the responsibility to fix on Apple (assuming Apple wants to support Pantone color definitions in their OS).

The basics on how to handle profiles correctly when working with LAB colors?

Hello,
I need to incorporate several blocks of color into an InDesign document. I have the colors in a list as LAB values. The document will be printed, and I have the profile for the printer/paper combo we plan to use.
Would one of you be willing to walk me through the Working Space, Color Management Policies, and Assign/Convert Profile setings that I should use to get the best result?
And, specifically - assuming I am using the Color Panel - not swatches - to color in the blocks: What settings should I use inorder to allow me to rely on the provided "out-of-gamut" warning to alert me if I am attempting to use a color that won't print correctly? I don't care if it is out-of-gamut for the purposes of my display - it is whether it is out-ouf-gamut for the purposes of printing that I want to know about.

Do the LAB colors look the same on the monitor regardless of which RGB
you are using? For example, if I switched from sRGB to Adobe RGB, would
the colors which had been specified in LAB still look the same?
Yes. But keep in mind using Lab doesn't let you get around having a well calibrated and profiled monitor. Lab is device independant so it doesn't have a profile, but in order to display it needs to be converted into your monitor's RGB space via your monitor profile, so the accuracy of your monitor profile is important if you are relying on the soft proof.
Is that what is called "Convert to Profile" in InDesign?
When you export to PDF you have the option to force all colors into one destination space (or not). In the Output tab of the Export dialog you can set your Destination to your printer's CMYK profile and the choose Convert to Destination as Color Conversion. That setting will convert your Lab colors to CMYK during the export. Convert to Profile... in the Edit menu let's you convert document RGB or CMYK colors from one RGB or CMYK space to another. It would have no effect on Lab colors.
Is the out-of-gamut warning only for CMYK?
Yes, it's using your document's CMYK space as the gamut
So if I specify a color using LAB which is out-of-gamut for the RGB
space I am using but in-gamut for my CMYK profile, I will NOT see a
warning?
Right. That would be unusual, but the Lab value for 100% cyan in your printer's CMYK space is likely out of gamut to any RGB space. But your destination is CMYK so that's the gamut you care about.

CS3 - Bridge Smart Object image to CS3 & Lab Color

I open an (NEF) image in Bridge, do some work, and open the smart object in CS3. When I go to Lab Color I get: “Changing modes can affect the appearance of smart objects. Rasterize smart object before mode change?” I don’t want this, correct?
After I choose “Don’t Rasterize” this dialog window appears: “Merge layers before mode change?” I choose no.
Within Channels (Lab Color) I go to delete “A” & “B” because I just want the Alpha Channel. However, I get “Flatten Layer?” and when I choose “No” I can’t delete “A” & “B.”
Solution?
~ Much Thanks ~

I should say I am trying to learn this software and stumbling through Mr. Kelby's 7 Point System book.
I found my error. I was highllighting the layers not clicking the eye icons off and on.
Thanks for all who look.
JB

Photoshop in Adobe RGB 16 bit don't fill a layer with paint bucket and a color 35.40.35.100.

I create a new file in RGB profile Adobe RGB 16bit
take the paint bucket and fill the layer with a color created by selector with the following parameters 35.40.35.100 CMYK and RGB corresponds to 24.20.18 the result is a full level of color 76.73.63.9 but in RGB corresponds to 24.20.18 because the values in cmyk not match ??

Could you please post screenshots (with the pertinent Panels visible) to illustrate the issue?
Are you not aware that you cannot reliably define a CMYK color in RGB because the transformation is performed through the Profile Connection Space (Lab) and depends on the involved Color Spaces/ICC profiles (edited) and the Color Settings?

How to select matching RGB and CMYK colors

Starting from scratch for a client, how do I select matching RGB and CMYK pairs?
Say we find a nice red colour in RGB for screen use, how do I then find the correct CMYK for print? And what assumptions do I have to make when doing this, if any?
Would it be the same for the other way around (choose CMYK first for print and then find the RGB equivalent)
Is it more sensible to start with a Pantone colour and then find the RGB and CMYK equivalents for that?
Many thanks
RobbieG
(I'm working with Ai, Ps and Id CS6)

Yes. Better to start with Pantone reference books where you are viewing the color in a reflective environment. As already mentioned, color on the monitor can be deceptive. And, I think the others are basiclt saying that you should have everything calibrated and use color management policies in your apps. There is a way to find CMYK equivalents using Photoshop's color palette. Let's say you have an RGB Red as the foreground color in Photoshop. If you double click on the swatch you will get Photoshop's color palette which lists the RGB percentages, CMYK percentages, LAB percentages, and HEX web color for that Red. You can go further and select "Custom" and the Pasntone Spot color palette opens and gives you the closest Spot color value for that Red. This however, depends on your color settings. That's why I recommend you start with the Pantone swatch book and get the perecentages of CMYK from their formula guide which is set to industry standard color.

ACR and LAB Color

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