Author Topic: color management ON looks worse. What profile do you use when it's OFF?  (Read 23741 times)

Offline rjp

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I am really confused about what this button does (or equivalently the "C" key).

I understand it toggles between "color managed" and "color not managed", but I can't figure out exactly what this means.

When it is off (icon dim, color not managed) I see one version of colors in my contact sheet, then when I click the button I see a different version of colors, but with all my testing I can't figure out just what this is doing.

I assume it is switching between rendering the images in two different color spaces.

I also assumed that when management is on it uses whatever colorspace is embedded in the image, but if that's so, then what is it using when management is off?

I have a situation now where the colors look much better when management is off so I'm trying to figure out what's happening.

As a test I have tried saving the original RAW (NEF) files after conversion to various colorspaces in NX. I have tried sRGB IEC61966-2.1, Nikon sRGB 4.0.0.3001, and even some generic sRGB that I get if I just extract the jpeg from the original NEF that has never been edited.

After ingesting all three of these into PM (either with or without the embed ICC profile option selected) the resulting images all look better (more saturated / slight hue shift / better black) with PM color management off.

I want to understand what's happening.



Offline Kirk Baker

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I am really confused about what this button does (or equivalently the "C" key).

I understand it toggles between "color managed" and "color not managed", but I can't figure out exactly what this means.

When it is off (icon dim, color not managed) I see one version of colors in my contact sheet, then when I click the button I see a different version of colors, but with all my testing I can't figure out just what this is doing.

I assume it is switching between rendering the images in two different color spaces.

I also assumed that when management is on it uses whatever colorspace is embedded in the image, but if that's so, then what is it using when management is off?

I have a situation now where the colors look much better when management is off so I'm trying to figure out what's happening.

As a test I have tried saving the original RAW (NEF) files after conversion to various colorspaces in NX. I have tried sRGB IEC61966-2.1, Nikon sRGB 4.0.0.3001, and even some generic sRGB that I get if I just extract the jpeg from the original NEF that has never been edited.

After ingesting all three of these into PM (either with or without the embed ICC profile option selected) the resulting images all look better (more saturated / slight hue shift / better black) with PM color management off.

I want to understand what's happening.

With color management turned off, no color matching is performed whatsoever.  The pixels as decoded from the image data are drawn to the screen without modification.  With color management, the colors in the image are matched via the profile associated with the image to the profile assigned to your monitor.  If your monitor does not have a calibrated profile assigned to it then you shouldn't bother using color management.  Low cost colorimeters are now available and the process of generating a calibrated ICC profile for your monitor is a fairly simple task.

HTH,

-Kirk

Offline rjp

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Thanks for the reply Kirk.

I have calibrated my monitor with the Pantone eyeOne and I do have a color profile from that process that I use. But it surprises me that you say the color management in PM is connected with this monitor profile. I was under the impression that the purpose of the monitor profile was strictly to make the monitor's measured RGB light output levels match the input digital values according to the predefined gamma curve and color temperature. I thought this profile was an overall correction for the monitor to be used for any and all display data, so I don't see why PM would want to match or even be concerned with this profile existing at all. If you can help me out here I'd appreciate it.

Ultimately what I want to do is make sure that my finished JPEG results look the same on most monitors, including those that don't have color management. I am assuming this means I should render them in sRGB for maximum compatibility. This is fine as I have no interest in editing in a larger gamut space.

It seems there are several stages in my workflow where colorspace is an option and I'm a little confused as to where to set things.  The Nikon camera itself has color modes (modes 1 and 3 are sRGB but 2 is adobe). THen Capture NX has the option of converting to any color space (I am presently always including this conversion step to nikon sRGB though I'm not sure it is necessary) I want to make sure that even if I do set the color mode to 2 to get the adobe mode 2 colors that the final result after editing still is written in sRGB space rather than aRGB.

Then I import these NEFS into PM and there seem to be two colorspace options, one is whether or not to embed colorspace in camera JPEGs upon ingest, and the other is whether to embed colorspace (ICC profile) when exporting. How should I set these? Maybe I'm confusion colorspace and ICC profile. If this is not the place for this discussion could you please point me to a good tutorial to better understand this.

Basically I want to know the following regarding colorspace:

(1) how do I set my camera? (i.e., must I use sRGB color modes?)
(2) How do I set NX's colorspace conversion steps?
(3) How do I set PM's colorspace (ICC profile) options

Thanks for any help,

Rich




Offline rjp

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Kirk,

I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?


Offline Kirk Baker

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Rich,

I have calibrated my monitor with the Pantone eyeOne and I do have a color profile from that process that I use. But it surprises me that you say the color management in PM is connected with this monitor profile. I was under the impression that the purpose of the monitor profile was strictly to make the monitor's measured RGB light output levels match the input digital values according to the predefined gamma curve and color temperature. I thought this profile was an overall correction for the monitor to be used for any and all display data, so I don't see why PM would want to match or even be concerned with this profile existing at all. If you can help me out here I'd appreciate it.

Have you assigned that color profile to your display via System Preferences?

Quote from: rjp
Ultimately what I want to do is make sure that my finished JPEG results look the same on most monitors, including those that don't have color management. I am assuming this means I should render them in sRGB for maximum compatibility. This is fine as I have no interest in editing in a larger gamut space.

It seems there are several stages in my workflow where colorspace is an option and I'm a little confused as to where to set things.  The Nikon camera itself has color modes (modes 1 and 3 are sRGB but 2 is adobe). THen Capture NX has the option of converting to any color space (I am presently always including this conversion step to nikon sRGB though I'm not sure it is necessary) I want to make sure that even if I do set the color mode to 2 to get the adobe mode 2 colors that the final result after editing still is written in sRGB space rather than aRGB.

Then I import these NEFS into PM and there seem to be two colorspace options, one is whether or not to embed colorspace in camera JPEGs upon ingest, and the other is whether to embed colorspace (ICC profile) when exporting. How should I set these? Maybe I'm confusion colorspace and ICC profile. If this is not the place for this discussion could you please point me to a good tutorial to better understand this.

Basically I want to know the following regarding colorspace:

(1) how do I set my camera? (i.e., must I use sRGB color modes?)
(2) How do I set NX's colorspace conversion steps?
(3) How do I set PM's colorspace (ICC profile) options

Since you're shooting in RAW (NEF) it doesn't really matter what profile you assign in the camera.  The RAW data is not affected by the profile you use in the camera.  Only the JPEGs or the embedded JPEG previews in your NEF files are affected by the profile you assign in the camera.  I generally recommend using Adobe RGB (1998) in the camera and then converting to sRGB where appropriate.

I cannot answer #1 or #2 since I am not real familiar with Nikon cameras or their software (I use Canon) but I'm sure someone else on the forums can help here.  As for #3, if you have color management turned on and you have a calibrated profile assigned to your display then you should see the best representation of the color in your photos.  Don't make the mistake of assigning Adobe RGB (1998) to your display in your OS's control panel.  It will most likely look bad.  You can assign Adobe RGB (1998) as your default ICC profile in the Color Management tab of the Photo Mechanic Preferences dialog if you wish, but it is only used when Photo Mechanic cannot determine the ICC profile for a given photo, otherwise the photo's embedded ICC profile or its tagged ICC profile will be used to map colors using the relative colorimetric method to display your photos.

As for tutorials, try "Real World Color Management" by Fraser, Murphy, and Bunting.  It explains color spaces and profiles quite well.

HTH,

-Kirk

Offline Kirk Baker

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I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

-Kirk

Offline rjp

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I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

-Kirk


Ah, that makes more sense now. I was under the impression that once a monitor was calibrated the profile was applied to every video signal sent to it.

I will buy the book you mentioned since I really need to get this right. The color difference is quite significant.

From what I've learned so far, there are two stages to color management.

(1) The monitor calibration profile (made by HW calibration tool), and
(2) The embedded colorspace of the image (i.e., sRGB aRBG, etc)

and these should never be interchanged. (1) belongs only in the monitor look up table, and (2) belongs only in the file as you said.

Q1: When I toggle PM color management on/off is it turning off both (1) and (2), or just (1)?

Q2: Should I select the option to "embed ICC profiles in camera JPEGS upon ingest" in PM properties? What do I get in each case here? Is this talking about (1) or (2)?

Q3: Should I select the option to "embed ICC profile" when using extract JPEG feature in PM? What do I get in each case? Again, is this profile (1) or (2)?

Let's suppose that in all cases I have started with the following input file:

A NEF file processed in capture NX with a final step of converting to sRGB. I assume this is changing only the embedded JPEG to sRGB since as you say the RAW data has no colorspace.

So given that this is an sRGB JPEG, how would Q1, Q2, and Q3 be answered?

Thanks.
« Last Edit: May 04, 2009, 03:16:41 PM by rjp »

Offline Kirk Baker

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Rich,

I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

Ah, that makes more sense now. I was under the impression that once a monitor was calibrated the profile was applied to every video signal sent to it.

I will buy the book you mentioned since I really need to get this right. The color difference is quite significant.

From what I've learned so far, there are two stages to color management.

(1) The monitor calibration profile (made by HW calibration tool), and
(2) The embedded colorspace of the image (i.e., sRGB aRBG, etc)

and these should never be interchanged. (1) belongs only in the monitor look up table, and (2) belongs only in the file as you said.

Q1: When I toggle PM color management on/off is it turning off both (1) and (2), or just (1)?

Nothing is turned off.  PM just doesn't ask ColorSync to match colors at all and just draws to the screen, basically saying along the way "this image is already using the monitor's destination profile".

Quote from: rjp
Q2: Should I select the option to "embed ICC profiles in camera JPEGS upon ingest" in PM properties? What do I get in each case here? Is this talking about (1) or (2)?

It would be #2, but you don't need to embed anything, the EXIF tag describes what profile should be used and works fine for sRGB and Adobe RGB (1998).  You can choose to embed the ICC profile and it won't hurt anything, the files will get slightly larger due to the profile data being inserted into the image data.

Quote from: rjp
Q3: Should I select the option to "embed ICC profile" when using extract JPEG feature in PM? What do I get in each case? Again, is this profile (1) or (2)?

#2.  You don't need to embed the ICC profile unless you want to.  The reasons for doing so are mainly when working with old software that doesn't know about the EXIF tag that describes which standard profile to use.  Most modern software works fine with the EXIF tag alone.

Quote from: rjp
Let's suppose that in all cases I have started with the following input file:

A NEF file processed in capture NX with a final step of converting to sRGB. I assume this is changing only the embedded JPEG to sRGB since as you say the RAW data has no colorspace.

Well actually it is the RAW data that is being developed from its linear image data to a non-linear image, then saved as a JPEG.  If they're truly converting to sRGB instead of just assigning the sRGB profile then they are making sure that none of the color in the JPEG lies outside of the sRGB gamut.

Quote from: rjp
So given that this is an sRGB JPEG, how would Q1, Q2, and Q3 be answered?

Q1, the answer above still applies.
Q2, the answer above still applies.
Q3, the answer above still applies.

HTH,

-Kirk

Offline rjp

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I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

Kirk,

I just did an experiment to test this and it does not seem to be behaving as you described.

What I did was to look at a photo preview in PM who's colorspace is sRGB, then I toggle the PM color management on/off using the "C" key. I observe a big difference in color saturation.

Then I open the Apple system preferences and switch the display profile back and forth between two different profiles. In each case I clearly observe the image colors changing whether or not PM color management is on or off.

So doesn't this mean that the image from PM is still having my display calibration profile applied to it even when PM color management is off? I thought you said it was being bypassed.
« Last Edit: May 04, 2009, 06:25:52 PM by Kirk Baker »

Offline Kirk Baker

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I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

Kirk,

I just did an experiment to test this and it does not seem to be behaving as you described.

What I did was to look at a photo preview in PM who's colorspace is sRGB, then I toggle the PM color management on/off using the "C" key. I observe a big difference in color saturation.

Then I open the Apple system preferences and switch the display profile back and forth between two different profiles. In each case I clearly observe the image colors changing whether or not PM color management is on or off.

So doesn't this mean that the image from PM is still having my display calibration profile applied to it even when PM color management is off? I thought you said it was being bypassed.


What profile are you assigning to your monitor?  Which two profiles?

-Kirk

Offline rjp

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I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

Kirk,

I just did an experiment to test this and it does not seem to be behaving as you described.

What I did was to look at a photo preview in PM who's colorspace is sRGB, then I toggle the PM color management on/off using the "C" key. I observe a big difference in color saturation.

Then I open the Apple system preferences and switch the display profile back and forth between two different profiles. In each case I clearly observe the image colors changing whether or not PM color management is on or off.

So doesn't this mean that the image from PM is still having my display calibration profile applied to it even when PM color management is off? I thought you said it was being bypassed.


What profile are you assigning to your monitor?  Which two profiles?

-Kirk


The monitor profiles I am talking about were obtained by hardware calibration with an EyeOne colorimeter. They can be named anything I like. The default names are something like Monitor_4_24_09-1 and Monitor_4_21_09-1 where the name is comprised of the date created.

I also tried the other profiles listed like the default imac profile that came from Apple (Which has a 1.8 gamma btw). The Profiles I usually use are calibrated to have 2.2 gamma and 6500K target white.

My point is that any monitor profile change in the Apple Display Preferences panel causes the displayed picture to change, whether PM has color management on or off.

So it appears that toggling PM color management has no impact on whether or not the color sync monitor profile gets used. It is always used.

« Last Edit: May 05, 2009, 05:40:44 AM by rjp »

Offline Kirk Baker

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I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

Kirk,

I just did an experiment to test this and it does not seem to be behaving as you described.

What I did was to look at a photo preview in PM who's colorspace is sRGB, then I toggle the PM color management on/off using the "C" key. I observe a big difference in color saturation.

Then I open the Apple system preferences and switch the display profile back and forth between two different profiles. In each case I clearly observe the image colors changing whether or not PM color management is on or off.

So doesn't this mean that the image from PM is still having my display calibration profile applied to it even when PM color management is off? I thought you said it was being bypassed.


What profile are you assigning to your monitor?  Which two profiles?

-Kirk


The monitor profiles I am talking about were obtained by hardware calibration with an EyeOne colorimeter. They can be named anything I like. The default names are something like Monitor_4_24_09-1 and Monitor_4_21_09-1 where the name is comprised of the date created.

I also tried the other profiles listed like the default imac profile that came from Apple (Which has a 1.8 gamma btw). The Profiles I usually use are calibrated to have 2.2 gamma and 6500K target white.

My point is that any monitor profile change in the Apple Display Preferences panel causes the displayed picture to change, whether PM has color management on or off.

So it appears that toggling PM color management has no impact on whether or not the color sync monitor profile gets used. It is always used.

OK, I just wanted to make sure you weren't switching between some other profiles like sRGB or Adobe RGB (1998).  Do you have Photoshop?  If so, do your images look correct when color managed in Photoshop?

-Kirk

Offline mbbphoto

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SO to paraphrase...

If....my monitor is calibrated, my Camera is set to sRGB and I shoot RAW:
In order for the preview to match the JPEG embedded in the RAW I set PM to view with the sRGB profile.

Is this correct?

Thanks as always

Marc
Marc

Offline Kirk Baker

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Marc,

SO to paraphrase...

If....my monitor is calibrated, my Camera is set to sRGB and I shoot RAW:
In order for the preview to match the JPEG embedded in the RAW I set PM to view with the sRGB profile.

Is this correct?

Not quite.  You only need to enable color management for thumbnails and previews.  PM will automatically see that your embedded previews were shot in sRGB and manage the colors appropriately.

You don't have to set PM to use sRGB as the default profile unless you have images that you know were shot in sRGB but do not have any profile assigned to them.  It won't hurt anything to set the default profile to sRGB but it is optional.

-Kirk

Offline rjp

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I calibrated my mac and have a color profile stored on it.

My impression was that this profile was used by the GPU as part of a lookup table for all video sent to the screen, but perhaps I am mistaken here.

Are you saying that if color management is turned off in PM it will cause PM to bypass this calibration color profile and write directly to the screen?

Yes, that is correct.

Kirk,

I just did an experiment to test this and it does not seem to be behaving as you described.

What I did was to look at a photo preview in PM who's colorspace is sRGB, then I toggle the PM color management on/off using the "C" key. I observe a big difference in color saturation.

Then I open the Apple system preferences and switch the display profile back and forth between two different profiles. In each case I clearly observe the image colors changing whether or not PM color management is on or off.

So doesn't this mean that the image from PM is still having my display calibration profile applied to it even when PM color management is off? I thought you said it was being bypassed.


What profile are you assigning to your monitor?  Which two profiles?

-Kirk


The monitor profiles I am talking about were obtained by hardware calibration with an EyeOne colorimeter. They can be named anything I like. The default names are something like Monitor_4_24_09-1 and Monitor_4_21_09-1 where the name is comprised of the date created.

I also tried the other profiles listed like the default imac profile that came from Apple (Which has a 1.8 gamma btw). The Profiles I usually use are calibrated to have 2.2 gamma and 6500K target white.

My point is that any monitor profile change in the Apple Display Preferences panel causes the displayed picture to change, whether PM has color management on or off.

So it appears that toggling PM color management has no impact on whether or not the color sync monitor profile gets used. It is always used.

OK, I just wanted to make sure you weren't switching between some other profiles like sRGB or Adobe RGB (1998).  Do you have Photoshop?  If so, do your images look correct when color managed in Photoshop?

-Kirk


I don't have Photoshop on this computer. I could add it if necessary to get to the bottom of this.

Another thing I noticed.

I was experimenting with the "extract embedded JPEGs" feature of PM. One of my favorites btw.

During the extraction process there is a pop up option that askes if I want to embed the ICC profile. As we discussed yesterday this is referring to the colorspace of the JPEG rather than the display profile.

I wanted to see what difference it made if I chose this option.

I ingested a NEF file into PM and noticed from the info viewer (and it's variables whose names I forget now) that PM says its profile was Nikon sRGB (embedded). It must be that NX embedded the nikon sRGB profile in the JPEG preview I assume. I did not mess with the colorspace option at all in NX on this one. Changed nothing but exposure from the camera NEF and resaved.

Now I extracted the JPEG from this RAW file with the option "embed ICC profile" selected. (Call this file1.jpg)

Then I extracted the JPEG from this file again without the "embed ICC profile" option selected (Call this file2.jpg)

I them loaded file1.jpg and file2.jpg into PM to see what profiles they each had.

file1.jpg was still Nikon sRGB (embedded), but file2.jpg was declared "undefined".

Interesting. I thought you said the colorspace profile was conveyed in the EXIF data and that the embedding step was unnecessary. Maybe I am confused.

Anyway, If I don't choose embed the file appears to be in an undefined colorspace in PM. Interestingly, if I toggle PM color management now while observing these two jpgs, the color on file1.jpg changes (as always) while the color on file2.jpg remains the same.

My conclusion (so far) from all this experimenting is that toggling color management on/off only tells PM whether or not to pay attention to the embedded color profile in the JPEG, and that if it is set to "off" it uses the same colorspace as it applies to "undefined" photos. And, this space, whatever it is, is definitely not sRGB. Probably it is just sending the digital RBG pixel values directly to the video processor with no conversion.

Let me ask you this. If you look at sRGB images in PM do they always look more saturated with color management "off" than "on"? I notice the reverse is true for aRGB, that is, more saturated with color management "on" than "off", but this made sense to me since the Adobe gamut is larger, and I assumed color management "off" was causing them to be viewed in sRGB space, which naturally would make them less saturated, but I've demonstrated this is not the default space for CM "off".







« Last Edit: May 05, 2009, 10:00:31 AM by rjp »