Colors, Colormanagement, Photoshop and the rest

Jürgen Herz wrote:

I used Spyder to create a ICC profile for my display. I put that into the systems (Win2K) "Color Management" tab and the correction software that came with the Spyder loads it at startup.

And while each application on my system actually displays the images with the same colors on my system, in Photoshop they’re more saturated.
I’d to lower the saturation of the display colors by 15% in the corresponding color options in Photoshop in order to match them with all other apps (including PSP7 which has explicit color management support).

What’s with the satuaration and which apps are wrong?

That depends on the settings in Photoshop. If your images have no embedded color profile (‘untagged’), Photoshop will assume something and that may be the wrong assumption. What Photoshop assumes is up to you: you can change that in the Color Settings. Untagged images are usually sRGB, and that is also how they are displayed in other applications, so let Photoshop do the same and you should get similar results.

Similar, but not identical: Be aware that non-color managed applications do NOT use your monitor profile. Yes, you have CALIBRATED your monitor and all applications benefit from that, but only color managed applications do actually use your monitor PROFILE to correct the colors they display (profiling and calibrating is not the same thing). That means that even if you make Photoshop assume sRGB color space for all untagged images, you may still see some small differences between Photoshop and other applications. They should be small though.

Finally, PSP 7 does NOT have full color management. This was finally introduced in PSP X. I don’t know exactly how much color management it does have, but don’t be surprised if there is a difference between Photoshop and PSP 7.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl/

Johan,

thanks for your anwer.

That depends on the settings in Photoshop. If your images have no embedded color profile (‘untagged’),

Though the difference applies to all images, the images I really use are tagged with sRGB or Adobe RGB.

but only color managed applications do actually use your monitor PROFILE to correct the colors they display (profiling and calibrating is not the same thing).

That’s interesting. I didn’t think about that.

What just came into my mind, does PS automatically use the monitor profile – because I can’t choose it anywhere (besides as Monitor Profile in Work Color Space (don’t know the exact words, I’m using PS with german UI)).

They should be small though.

Should, but they’re in fact 15% saturation. That’s not even small.

but don’t be surprised if there is a difference between Photoshop and PSP 7.

Ok, so I’m not.

Regards,
Jürgen

Jürgen Herz wrote:

That depends on the settings in Photoshop. If your images have no embedded color profile (‘untagged’),

Though the difference applies to all images, the images I really use are tagged with sRGB or Adobe RGB.

In that case I’m suspecting your monitor profile. It may be no good. If Photoshop is the only application that uses it, but it’s either not good or you’ve set the wrong monitor profile, then this could happen. You could start by calibrating your monitor again. Or you could see if it makes a difference if you choose sRGB for your monitor profile instead of the Spyder profile. If it does, you’ll know there is something wrong with that Spyder profile.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl

Johan W. Elzenga wrote:

Jürgen Herz wrote:

That depends on the settings in Photoshop. If your images have no embedded color profile (‘untagged’),

Though the difference applies to all images, the images I really use are tagged with sRGB or Adobe RGB.

In that case I’m suspecting your monitor profile. It may be no good. If Photoshop is the only application that uses it, but it’s either not good or you’ve set the wrong monitor profile, then this could happen. You could start by calibrating your monitor again. Or you could see if it makes a difference if you choose sRGB for your monitor profile instead of the Spyder profile. If it does, you’ll know there is something wrong with that Spyder profile.

I may be wrong here, but I’m thinking that all apps use the monitor profile.

When I start my Windows XP system, the screen background, which is largely dark blue/navy hues, has a distinct reddish cast. About halfway through loading of the startup apps, the red cast instantly goes away. Correspondingly, the green and blue ‘curves’ for my monitor profile (Gretag-Macbeth Eye One) are quite linear, but the red ‘curve’ definitely takes red out of the dark red region. Thus I’m under the impression that the monitor profile is applied at the operating system level, and is used for all apps. I know that there is a loader with my profiling software, and for those who use Adobe Gamma, there is the Adobe Gamma loader. I assume Spyder also has a loader.

I think the aspects that Photoshop color manages and most other apps don’t has to do with the ability to recognize and correctly use and manipulate profiles, i.e. use an embedded profile, convert to another profile, assign a profile, soft proof, etc.

As far as the 15% oversaturated aspect of the question, as a general condition, an sRGB file displayed in Adobe RGB working space will appear oversaturated. 15% might be in the range here. I don’t know how to quantify this. Conversely, an Adobe RGB image displayed in an sRGB working space will appear undersaturated. This often happens when people work in Photoshop, save with an Adobe RGB profile embedded, then post on the web (basically sRGB space). There are many posts in the newsgroups from people complaining about their ‘washed out’ looking photos.

Mike G. wrote:

In that case I’m suspecting your monitor profile. It may be no good. If Photoshop is the only application that uses it, but it’s either not good or you’ve set the wrong monitor profile, then this could happen. You could start by calibrating your monitor again. Or you could see if it makes a difference if you choose sRGB for your monitor profile instead of the Spyder profile. If it does, you’ll know there is something wrong with that Spyder profile.

I may be wrong here, but I’m thinking that all apps use the monitor profile.

That is a common misunderstanding. All apps benefit from the calibration of your monitor, but on Windows each application has to be specifically written to use the monitor profile when they send something to the screen. Most applications are not, not even most graphical applications. On a Macintosh this is different, because there the system takes care of this (ColorSync).

When I start my Windows XP system, the screen background, which is largely dark blue/navy hues, has a distinct reddish cast. About halfway through loading of the startup apps, the red cast instantly goes away. Correspondingly, the green and blue ‘curves’ for my monitor profile (Gretag-Macbeth Eye One) are quite linear, but the red ‘curve’ definitely takes red out of the dark red region. Thus I’m under the impression that the monitor profile is applied at the operating system level, and is used for all apps. I know that there is a loader with my profiling software, and for those who use Adobe Gamma, there is the Adobe Gamma loader. I assume Spyder also has a loader.

No, that is not your monitor profile being loaded, but the CLUT. That’s the calibration step you are seeing. The monitor profile has a different function. It is used to convert images ‘on the fly’ from your working color space to the monitor color space when they are sent to the monitor. An application has to do that when the image is displayed, it not something you can load at startup.

I think the aspects that Photoshop color manages and most other apps don’t has to do with the ability to recognize and correctly use and manipulate profiles, i.e. use an embedded profile, convert to another profile, assign a profile, soft proof, etc.

That is only one part of it. The other part is using the monitor profile when displaying the image.

As far as the 15% oversaturated aspect of the question, as a general condition, an sRGB file displayed in Adobe RGB working space will appear oversaturated. 15% might be in the range here.

Correct, and that was the first thing I was looking for. However, the OP says that it happens with both AdobeRGB and sRGB images, so that cannot be the reason, at least not for ALL images.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.nl

"Johan W. Elzenga" wrote in message

J

Mike G. wrote:

Johan W. Elzenga wrote:

Jürgen Herz wrote:

That depends on the settings in Photoshop. If your images have no embedded color profile (‘untagged’),

Though the difference applies to all images, the images I really use are tagged with sRGB or Adobe RGB.

In that case I’m suspecting your monitor profile. It may be no good. If Photoshop is the only application that uses it, but it’s either not good or you’ve set the wrong monitor profile, then this could happen. You could start by calibrating your monitor again. Or you could see if it makes a difference if you choose sRGB for your monitor profile instead of the Spyder profile. If it does, you’ll know there is something wrong with that Spyder profile.

I may be wrong here, but I’m thinking that all apps use the monitor profile.

When I start my Windows XP system, the screen background, which is largely dark blue/navy hues, has a distinct reddish cast. About halfway through loading of the startup apps, the red cast instantly goes away. Correspondingly, the green and blue ‘curves’ for my monitor profile (Gretag-Macbeth Eye One) are quite linear, but the red ‘curve’ definitely takes red out of the dark red region. Thus I’m under the impression that the monitor profile is applied at the operating system level, and is used for all apps. I know that there is a loader with my profiling software, and for those who use Adobe Gamma, there is the Adobe Gamma loader. I assume Spyder also has a loader.

I think the aspects that Photoshop color manages and most other apps don’t has to do with the ability to recognize and correctly use and manipulate profiles, i.e. use an embedded profile, convert to another profile, assign a profile, soft proof, etc.

As far as the 15% oversaturated aspect of the question, as a general condition, an sRGB file displayed in Adobe RGB working space will appear oversaturated. 15% might be in the range here. I don’t know how to quantify this. Conversely, an Adobe RGB image displayed in an sRGB working space will appear undersaturated. This often happens when people work in Photoshop, save with an Adobe RGB profile embedded, then post on the web (basically sRGB space). There are many posts in the newsgroups from people complaining about their ‘washed out’ looking photos.

No, you aren’t wrong. Monitor calibration corrects the colors of the monitor. The only connection between that and Photoshop are your eyes.

Clyde

Johan W. Elzenga wrote:

Mike G. wrote:

In that case I’m suspecting your monitor profile. It may be no good. If Photoshop is the only application that uses it, but it’s either not good or you’ve set the wrong monitor profile, then this could happen. You could start by calibrating your monitor again. Or you could see if it makes a difference if you choose sRGB for your monitor profile instead of the Spyder profile. If it does, you’ll know there is something wrong with that Spyder profile.

I may be wrong here, but I’m thinking that all apps use the monitor profile.

That is a common misunderstanding. All apps benefit from the calibration of your monitor, but on Windows each application has to be specifically written to use the monitor profile when they send something to the screen. Most applications are not, not even most graphical applications. On a Macintosh this is different, because there the system takes care of this (ColorSync).

When I start my Windows XP system, the screen background, which is largely dark blue/navy hues, has a distinct reddish cast. About halfway through loading of the startup apps, the red cast instantly goes away. Correspondingly, the green and blue ‘curves’ for my monitor profile (Gretag-Macbeth Eye One) are quite linear, but the red ‘curve’ definitely takes red out of the dark red region. Thus I’m under the impression that the monitor profile is applied at the operating system level, and is used for all apps. I know that there is a loader with my profiling software, and for those who use Adobe Gamma, there is the Adobe Gamma loader. I assume Spyder also has a loader.

No, that is not your monitor profile being loaded, but the CLUT. That’s the calibration step you are seeing. The monitor profile has a different function. It is used to convert images ‘on the fly’ from your working color space to the monitor color space when they are sent to the monitor. An application has to do that when the image is displayed, it not something you can load at startup.

I think the aspects that Photoshop color manages and most other apps don’t has to do with the ability to recognize and correctly use and manipulate profiles, i.e. use an embedded profile, convert to another profile, assign a profile, soft proof, etc.

That is only one part of it. The other part is using the monitor profile when displaying the image.

As far as the 15% oversaturated aspect of the question, as a general condition, an sRGB file displayed in Adobe RGB working space will appear oversaturated. 15% might be in the range here.

Correct, and that was the first thing I was looking for. However, the OP says that it happens with both AdobeRGB and sRGB images, so that cannot be the reason, at least not for ALL images.

I think you are wrong here. My Spyder2 software says that it is loading the monitor profile at login time. I figure that Pantone/ColorVision probably know what they are talking about when they wrote that.

Color management systems, like that in XP or ColorSync, are a collection of standards that allow correct colors on devices that have no physical connection. It is a stateless standard – kind of. However, any color management system ASSUMES that every device is calibrated.

Photoshop uses color spaces (different than color device profiles) to define the range of colors that it were used for a particular file. (Notice that all those "profiles" you convert to inside Photoshop are all really "color spaces".) When it sends that file to a device, it has to translate those colors into colors that work for that device. For example, you printer uses very different color definition than AdobeRGB, sRGB, or any other color space. (Notice that all those "profiles" you convert to in Photoshop are NOT device profiles.) Because you have a printer driver and paper profiles for that paper/printer combination, Photoshop knows how to convert the colors in the file to ones that the printer driver can use. It does this at printing time only.

Photoshop assumes that your monitor is correct. So it just sends what it has to the monitor. OK, it is the operating system that sends it. It is also the operating system that holds the monitor profile and sends it to the video system. My XP/Spyder2 software claims to be actually writing that profile to the video card.

Because Photoshop assumes that you have calibrated monitor, it doesn’t convert anything to display it. This is good, because that step would really slow things down inside Photoshop.

Now, if I send you a file from Photoshop, the only part of color management that goes along with it is the color space definition. I assume that you have a properly calibrated monitor AND proper paper/printer profiles. If that is the case, I’m pretty sure you will see what I created in Photoshop. Well, at least it will be very close.

Just remember that Photoshop doesn’t store any device profile in its files. It doesn’t need to; the system is based on the assumption that other calibrated devices will be there and the conversion will happen correctly.

Clyde

You might find the following interesting …

http://www.adobe.com/support/techdocs/321608.html

It’s good to calibarte you rmonitor but when you get sick of trusting in faith, go with the numbers in photoshop’s info palette. Hit the blues, greens and skin tones with the numbers. plus highlight and shadows.

It’s one thing to calibrate your monitor, but the human adjusts neutrals, and the color of your wall? are they mid gray to reduce color casts?
is your studio using fluorescent lights? daylight? which time of day?

you use numbers before visual. Knowing the correct numbers takes experience.

PacMan

On 2006-02-09 11:48:32 -0400, "Jürgen Herz" said:

Hi,

I used Spyder to create a ICC profile for my display. I put that into the systems (Win2K) "Color Management" tab and the correction software that came with the Spyder loads it at startup.

And while each application on my system actually displays the images with the same colors on my system, in Photoshop they’re more saturated.
I’d to lower the saturation of the display colors by 15% in the corresponding color options in Photoshop in order to match them with all other apps (including PSP7 which has explicit color management support).

What’s with the satuaration and which apps are wrong?

Bye,
Jürgen

—
Cheers
PacMan

http://homepage.mac.com/brown.joey/portfolio/

Johan W. Elzenga wrote:

Jürgen Herz wrote:

That depends on the settings in Photoshop. If your images have no embedded color profile (‘untagged’),

Though the difference applies to all images, the images I really use are tagged with sRGB or Adobe RGB.

In that case I’m suspecting your monitor profile. It may be no good. If Photoshop is the only application that uses it, but it’s either not good or you’ve set the wrong monitor profile, then this could happen. You could start by calibrating your monitor again. Or you could see if it makes a difference if you choose sRGB for your monitor profile instead of the Spyder profile. If it does, you’ll know there is something wrong with that Spyder profile.

Hello All,

I’m finding this a very interesting and somewhat perplexing thread. When I consider what I know, what I thought I knew, and what several other posters have added, I see what might (or not) be some conflicting ideas. I’ve done a lot of reading on this in the past couple of days trying to sort it out. Mostly been reviewing Real World Color Management and Real World Photoshop 7, along with some of the web references suggested, and feel that maybe we’re all not saying things that are so different.

To me, I’ve gotten to the point of feeling that the answer lies in the question "Just what goes into the video LUT?" Let me lay out a scenario, and let’s exclude Windows NT from the discussion, since it doesn’t let software write to the LUT. First, most current profiling software that’s part of a hardware/software solution (ie GMB, Monaco, Spyder) combines the calibration and profile generation. We start with the monitor Brightness and Contrast adjustments, which essentially set the white point and black point. These are monitor hardware adjustments. Next we set a preset monitor color temperature, or adjust gain on 2 or 3 color guns, depending on the monitor. This sets monitor Color Temperature, and is another monitor hardware adjustment. Next, a number of greyscale and color patches are displayed and automatically read, and the profiling software compares them against known values. From this, an icc profile is generated, generally in the form of a LUT. I’m assuming (but not sure) that target gamma is factored in at this point. Next, the profiling software loads "information" into the video card LUT, and sets a startup loader which reloads that information each time the system is started.

So we get to the crux of the question, which is: Is it the icc profile information which the profiling software loads into the video LUT at startup? If so, then isn’t in fact the profile available to all apps? If not, what *is* loaded into the video LUT? From what I’ve read, my *impression is that the icc LUT *is* what gets loaded to the video LUT, but I’ve not been able to find this clearly stated.

I’ve read many times about Photoshop making the monitor profile corrections ‘on the fly’, but don’t know what this means. Clearly, Photoshop knows about the monitor profile, assuming it’s been correctly installed. Does it know if it’s been loaded into the video LUT, if in fact that happens? Certainly it must. I can see that a correction (small?) would be needed if the hardware calibration was done to a color temperature other than 6600 deg K, which I believe is the white point of both Adobe RGB and sRGB, and that an even larger correction would be needed if the monitor were calibrated to, say, 5000 or 9300 deg K. Of course if the icc LUT *isn’t* what goes into the video LUT, then the answer becomes clear.

Finally, from reading the Adobe tech paper referenced by C J Southern, it was not clear to me if the Adobe Gamma loader put profile information into the video LUT. I got the impression it did not. In that case, of course the whole profile correction would be made ‘on the fly’.

Well folks, that’s the scenario, with a lot of options, questions, unknowns, etc. I hope people will jump in on this and add their thoughts. Thanks to all for their ideas to this point, and for their future contributions.

Best Regards,
Mike

Johan W. Elzenga wrote:

Jürgen Herz wrote:

That depends on the settings in Photoshop. If your images have no embedded color profile (‘untagged’),

Though the difference applies to all images, the images I really use are tagged with sRGB or Adobe RGB.

In that case I’m suspecting your monitor profile. It may be no good. If Photoshop is the only application that uses it, but it’s either not good or you’ve set the wrong monitor profile, then this could happen. You could start by calibrating your monitor again. Or you could see if it makes a difference if you choose sRGB for your monitor profile instead of the Spyder profile. If it does, you’ll know there is something wrong with that Spyder profile.

Hello All,

I’m finding this a very interesting and somewhat perplexing thread. When I consider what I know, what I thought I knew, and what several other posters have added, I see what might (or not) be some conflicting ideas. I’ve done a lot of reading on this in the past couple of days trying to sort it out. Mostly been reviewing Real World Color Management and Real World Photoshop 7, along with some of the web references suggested, and feel that maybe we’re all not saying things that are so different.

To me, I’ve gotten to the point of feeling that the answer lies in the question "Just what goes into the video LUT?" Let me lay out a scenario, and let’s exclude Windows NT from the discussion, since it doesn’t let software write to the LUT. First, most current profiling software that’s part of a hardware/software solution (ie GMB, Monaco, Spyder) combines the calibration and profile generation. We start with the monitor Brightness and Contrast adjustments, which essentially set the white point and black point. These are monitor hardware adjustments. Next we set a preset monitor color temperature, or adjust gain on 2 or 3 color guns, depending on the monitor. This sets monitor Color Temperature, and is another monitor hardware adjustment. Next, a number of greyscale and color patches are displayed and automatically read, and the profiling software compares them against known values. From this, an icc profile is generated, generally in the form of a LUT. I’m assuming (but not sure) that target gamma is factored in at this point. Next, the profiling software loads "information" into the video card LUT, and sets a startup loader which reloads that information each time the system is started.

So we get to the crux of the question, which is: Is it the icc profile information which the profiling software loads into the video LUT at startup? If so, then isn’t in fact the profile available to all apps? If not, what *is* loaded into the video LUT? From what I’ve read, my *impression* is that the icc LUT *is* what gets loaded to the video LUT, but I’ve not been able to find this clearly stated.

I’ve read many times about Photoshop making the monitor profile corrections ‘on the fly’, but don’t know what this means. Clearly, Photoshop knows about the monitor profile, assuming it’s been correctly installed. Does it know if it’s been loaded into the video LUT, if in fact that happens? Certainly it must. I can see that a correction (small?) would be needed if the hardware calibration was done to a color temperature other than 6600 deg K, which I believe is the white point of both Adobe RGB and sRGB, and that an even larger correction would be needed if the monitor were calibrated to, say, 5000 or 9300 deg K. Of course if the icc LUT *isn’t* what goes into the video LUT, then the answer becomes clear.

Finally, from reading the Adobe tech paper referenced by C J Southern, it was not clear to me if the Adobe Gamma loader put profile information into the video LUT. I got the impression it did not. In that case, of course the whole profile correction would be made ‘on the fly’.

Well folks, that’s the scenario, with a lot of options, questions, unknowns, etc. I hope people will jump in on this and add their thoughts. Thanks to all for their ideas to this point, and for their future contributions.

Best Regards,
Mike

"Mike G." wrote in message

[re colormanagement in reference to monitor display]
….

To me, I’ve gotten to the point of feeling that the answer lies in the question "Just what goes into the video LUT?"

This is exactly half of the issue: calibration. The other half is characterization.

Calibration is something we all do when we tweak the contrast or brightnes of a monitor. It means adjusting the monitor to a known state by a combination of manual adjustment of the monitor controls, and it often includes software adjustment of the *video* LUT. The end result of calibration is a known appearance of the black and white points, color temp, and gamma. It may be done visually, or using a device.

Characterization, on the other hand, defines the numbers behind the appearance of pure red, green, and blue, aka the primaries (which are not adjustable), as well as gamma. Characterization is the same as profiling, and it defines the translation of numeric color values to displayed color.

Monitor profiles typically use a matrix based mathmatics to convert numeric RGB values to output RGB values. A matrix is a compact representation that works well for CRTs, and for Photoshop’s working color spaces, such as Adobe RGB and sRGB.

Other devices, including certain LCD monitors, printers, and scanners, use a more complex multi-dimensional look up table – called a LUT for short. The icc LUT is different from the th the video LUT.

Let me lay out a scenario, and let’s exclude Windows NT from the discussion, since it doesn’t let software write to the LUT.

Not important, but: NT does have a system interface that allows the LUT to be modified.

First, most current profiling software that’s part of a hardware/software solution (ie GMB, Monaco, Spyder) combines the calibration and profile generation. We start with the monitor Brightness and Contrast adjustments, which essentially set the white point and black point. These are monitor hardware adjustments. Next we set a preset monitor color temperature, or adjust gain on 2 or 3 color guns, depending on the monitor. This sets monitor Color Temperature, and is another monitor hardware adjustment.

Absolutely. The monitor color temperature may also be set via the video LUT in Adobe Gamma (calibraton) or measured (characterization). In general, anything that visibly alters the display is part of calibration, and anything that does not (such as determination of color temp) is calibration.

Next, a number of greyscale and color patches are displayed and automatically read, and the profiling software compares them against known values. From this, an icc profile is generated, generally in the form of a LUT.

The Spyder software has a choice at this point- it can alter the display of colors by changing the video LUT (calibration), or measure the displayed colors, and reflect that color output value in the monitor profile (characterization).

Adobe gamma does a similar operation, using the gamma sliders, and this is part of calibration, not characterization.

I’m assuming (but not sure) that target gamma is factored in at this point. Next, the profiling software loads "information" into the video card LUT, and sets a startup loader which reloads that information each time the system is started.

More specifically, the brightness for each RGB value is determined, and this characterizes the gamma of the display.

So we get to the crux of the question, which is: Is it the icc profile information which the profiling software loads into the video LUT at startup?

The icc profile defines what the video system will display for each RGB value. The profile is not loaded into the video LUT, this is stored somewhere else.

If so, then isn’t in fact the profile available to all apps?

No. What is available to all apps is the video LUT, which will display RGB numbers at a specified color temp, white point, gamma, etc. The video profile is only interesting to color aware applications, meaning those that translate colors from one color space to another. Photoshop does this when it translates colors from your working color space (e.g. Adobe RGB) to your monitor color space.

If not, what *is* loaded into the video LUT? From what I’ve read, my *impression is that the icc LUT *is* what gets loaded to the video LUT, but I’ve not been able to find this clearly stated.

As mentioned, an icc LUT is a different animal from a video LUT. The video LUT is loaded at startup time, by a program such as the spyder software or Adobe Gamma Loader. This is another source of problems, when two different startup apps modify the video LUT, resulting in a doubly corrected display.

I’ve read many times about Photoshop making the monitor profile corrections ‘on the fly’, but don’t know what this means.

Yes, Photoshop converts from your working space to your monitor space on the fly. This results in a particular image looking the same on any display that has been properly calibrated (with Adobe Gamma or a calibration device), provided that image is tagged with its working space profile.

Clearly, Photoshop knows about the monitor profile, assuming it’s been correctly installed. Does it know if it’s been loaded into the video LUT, if in fact that happens? Certainly it must. I can see that a correction (small?) would be needed if the hardware calibration was done to a color temperature other than 6600 deg K, which I believe is the white point of both Adobe RGB and sRGB, and that an even larger correction would be needed if the monitor were calibrated to, say, 5000 or 9300 deg K. Of course if the icc LUT *isn’t* what goes into the video LUT, then the answer becomes clear.

You have all the right puzzle pieces. Photoshop ignores anything havning to do with the video LUT, and uses only information in the profile. The monitor profile, together with the working space profile, contains enough information to convert
an RGB value from your image to a display value.

Finally, from reading the Adobe tech paper referenced by C J Southern, it was not clear to me if the Adobe Gamma loader put profile information into the video LUT. I got the impression it did not. In that case, of course the whole profile correction would be made ‘on the fly’.

Again, it the split between characterization and calibration is key to understanding how this works. The Adobe Gamma Loader deals only with calibration data, primarily the video LUT, which it loads into the video card at startup.

One other point of information, to support older versions of Windows, Adobe Gamma would also place the name of the monitor profile in the the registry, so that Photoshop could find it later and use it for display conversion. This mechanism is still used, even in newer versions of Windows, and for that reason it is good to open, then immediately close, the monitor profile with Adobe Gamma.

Well folks, that’s the scenario, with a lot of options, questions, unknowns, etc. I hope people will jump in on this and add their thoughts. Thanks to all for their ideas to this point, and for their future contributions.

Color calibration is a mess. If you want proof, check out the great heap of obfuscation, er I mean, the font of all color profile wisdom, known as www.color.org .
—
Mike Russell
www.curvemeister.com

Mike Russell wrote:

Mike,
Thanks for taking the time to go through this for me—again. It’s an expanded version of what Johan wrote, and slowly I think it’s sinking in. I found your comment below to be like turning on a light switch – very helpful.

In general,
anything that visibly alters the display is part of calibration, and anything that does not (such as determination of color temp) is <calibration>.

[Assumed you meant *characterization* here]

That comment in conjunction with something I read elsewhere nailed it down for me. That other piece was an explanation that the vcgt was part of the calibration process, but the info was stored in the icc profile for convenience, and loaded into the vLUT at startup. That explained all of the oblique references to profile information being loaded to the vLUT. Maybe this was clear to others all along, but previously, I just didn’t get it. Talk about muddying the dividing lines.

Johan,
Thanks so much for your explanation. I’m sorry I was too dense to get it the first time around. Everything you said makes sense now.

Clyde,
Thanks for your comments. According to Mike Russell, if I understood correctly, it seems that the Spyder software is somewhat unique in allowing some icc characterization (profile) information to be added to the vLUT. I assume this is what you were referring to. It makes me wonder if it’s possible the OP did this, and ended up somehow with Photoshop doing a ‘double correction’.

CJ,
Thanks for the Adobe techdoc link. I reread it and it makes sense now.

Have a good day everyone. Sorry it took me so long to absorb this. I sincerely appreciate all of the help.

Mike G.

I have the same problem. and the most anoing is that workflow with Adob Bridge and PS is very different.

First, I got the monitor profile by MacBeth eye one. So, theoreticly PS should work fine. However, the same problem, in PS the image was ok and doing save for web, the image gets darker and less saturated. I color settings: Working profile was sRGB, and under Monitor – "profil from iOne"

Tried many things:
1. removed Adoma gamma loader from start up. then the profile, whic has been set up in display/prop … as default monitor, did not work.
2. If you load adobe gamma, ether by hand, or put back in start up, i
seems that all applications respond to this profile, except PS. I tried another profile, just to make sure that the iOne profile is no corrupted, and the same scene.

3. What I really got, is to put in PS View/proof colors/monitor. then what I see on the screen in PS, is the same as on the "Save for web screen

I have read all this thread, but did not get everything, so I am no sure about what I did. Does it make any sence at all? Should Colo proof be checked or not?

thanks everyone

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alphamaste
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