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Author Topic: How do I know if I'm "Out of gamut"?  (Read 3000 times)

dreed

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How do I know if I'm "Out of gamut"?
« on: October 18, 2012, 09:11:13 am »

I'm looking at a bunch of images that I've taken and they just don't look right and no amount of fiddling with them seems to get them to look right, so I'm left wondering, are certain parts of them simply out of gamut?

My problem is that I don't know... and I don't know if the computer can tell me that it's out of gamut. And by being out of gamut, I don't mean too bright or dark, I mean that colour brown just doesn't look right or that shade of blue isn't right or...

One question here is, does gamut apply to the sensor or does gamut only apply to the output medium (be it a monitor or printer/paper)?

The other question is more basic - is there any way for LR or anything else to tell me when a pixel (or two or three) is out of the gamut range of my monitor?
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bjanes

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Re: How do I know if I'm "Out of gamut"?
« Reply #1 on: October 18, 2012, 09:45:08 am »

I'm looking at a bunch of images that I've taken and they just don't look right and no amount of fiddling with them seems to get them to look right, so I'm left wondering, are certain parts of them simply out of gamut?

My problem is that I don't know... and I don't know if the computer can tell me that it's out of gamut. And by being out of gamut, I don't mean too bright or dark, I mean that colour brown just doesn't look right or that shade of blue isn't right or...

One question here is, does gamut apply to the sensor or does gamut only apply to the output medium (be it a monitor or printer/paper)?

The other question is more basic - is there any way for LR or anything else to tell me when a pixel (or two or three) is out of the gamut range of my monitor?

Undoubtedly, many your images contain colors and luminances that are out of the gamut of both your monitor and printer. The easiest way to check these gamuts is with a gamut mapping utility such as Colorthink. For this to be of any value requires that you have accurate profiles of both these devices. Here is an example with out of gamut yellows. The yellow dots are elements of the image.

Regards,

Bill

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robgo2

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Re: How do I know if I'm "Out of gamut"?
« Reply #2 on: October 18, 2012, 10:13:54 am »

In Photoshop, you can try View>Gamut Warning, which will show you out of gamut areas for the particular profile that you have chosen in Proof Setup.  I do not know if this if available in Lightroom (which I do not use,) but I suspect that it is.

Rob
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hugowolf

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Re: How do I know if I'm "Out of gamut"?
« Reply #3 on: October 18, 2012, 10:29:10 am »

You can softproof in Lightroom. Turn softproofing on in the development module. Then at the top left of the histogram there is a button to show out-of-gamut areas for the monitor, and on the top right of the histogram there is a button for displaying out-of-gamut areas for another profiled output device, usually a printer/paper profile. There is a list of profiles to select from.

Brian A
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bjanes

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Re: How do I know if I'm "Out of gamut"?
« Reply #4 on: October 18, 2012, 11:08:59 pm »

You can softproof in Lightroom. Turn softproofing on in the development module. Then at the top left of the histogram there is a button to show out-of-gamut areas for the monitor, and on the top right of the histogram there is a button for displaying out-of-gamut areas for another profiled output device, usually a printer/paper profile. There is a list of profiles to select from.

Brian A

The gamut warnings in Lightroom are helpful, but they don't tell you if you are out of gamut by a very small or large amount. The Colorthink gamut warnings do quantify the gamut mismatch but don't let you know where in the image the out of gamut colors reside. Gamutvision provides a pseudocolor image indicating where the out of gamut colors are in the image and the amount of the out of gamut in terms of DeltaE

Julianne Kost has nice tutorial on softproofing in Lightroom 4.

Regards,

Bill

Regards,

Bill
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ErikKaffehr

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Re: How do I know if I'm "Out of gamut"?
« Reply #5 on: October 19, 2012, 12:58:35 am »

Hi,

There are at least three different gamuts:

1) The gamut of the RGB you are working in. LR uses a version of Prophoto RGB and that should eliminate that problem.

2) The gamut of your monitor. Some colors cannot be displayed on your screen.

3) The gamut of your printing device

2-3 are covered pretty well by Lightroom's "softproof". I would recommend the Lightroom videos here on LuLa where Jeff Schewe explains hot it works. I'm sure there are other good descriptions.

Bill referred to a video with Julianne Kost. I have not seen that video but it's probably excellent. Stuff that Julianne does used to be excellent.

I don't think the issues with printing are to bad, modern printers have nice gamuts and at least glossy and luster papers have a wide tonal range. Perceptual rendering intent fixes minor issues. If you cannot see colors on screen, you should probably sort out the issue on screen.

Best regards
Erik


One question here is, does gamut apply to the sensor or does gamut only apply to the output medium (be it a monitor or printer/paper)?

The other question is more basic - is there any way for LR or anything else to tell me when a pixel (or two or three) is out of the gamut range of my monitor?
« Last Edit: October 19, 2012, 12:14:43 pm by ErikKaffehr »
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Erik Kaffehr
 

bjanes

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Re: How do I know if I'm "Out of gamut"?
« Reply #6 on: October 19, 2012, 07:58:53 am »


There are at least three different gamuts:

1) The gamut of the RGB you are working in. LR uses a version of Prophoto RGB and that should eliminate that problem.

2) The gamut of your monitor. Some colors cannot be displayed on your screen.

3) The gamut of your printing device

2-3 are covered pretty well by Lightroom's "softproof". I would recommend the Lightroom videos here on LuLa where Jeff Schewe explains hot it works. I'm sure there are other good descriptions.

BJL referred to a video with Julianne Kost. I have not seen that video but it's probably excellent. Stuff that Julianne does used to be excellent.

I don't think the issues with printing are to bad, modern printers have nice gamuts and at least glossy and luster papers have a wide tonal range. Perceptual rendering intent fixes minor issues. If you cannot see colors on screen, you should probably sort out the issue on screen.

Eric,

I would add another gamut to your list: the gamut of the scene. This is where gamut mapping software such as colorthink come in. In my own work, I have encountered the most gamut problems when photographing flowers at the local botanical garden. One might want to add the gamut of the camera, but strictly speaking cameras do not have a gamut (see here). Most sensors cover the whole visual spectrum, but not necessarily with colorimetric accuracy.

Regards,

Bill
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hugowolf

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Re: How do I know if I'm "Out of gamut"?
« Reply #7 on: October 19, 2012, 11:15:14 am »

I would add another gamut to your list: the gamut of the scene. This is where gamut mapping software such as colorthink come in. In my own work, I have encountered the most gamut problems when photographing flowers at the local botanical garden. One might want to add the gamut of the camera, but strictly speaking cameras do not have a gamut (see here). Most sensors cover the whole visual spectrum, but not necessarily with colorimetric accuracy.
So the gamut of the scene as captured in the camera's raw data?

Brian A
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darlingm

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Re: How do I know if I'm "Out of gamut"?
« Reply #8 on: October 19, 2012, 02:43:58 pm »

. . . The Colorthink gamut warnings do quantify the gamut mismatch but don't let you know where in the image the out of gamut colors reside. Gamutvision provides a pseudocolor image indicating where the out of gamut colors are in the image and the amount of the out of gamut in terms of DeltaE. . .

Colorthink can show you where in the image the out of gamut colors reside.  You can choose the deltaE values for the boundaries between green/yellow/orange/red.

That being said, I'm jealous of your Gamutvision snapshot - divided into many more levels than 4.


Photo by David Iliff.  License CC-BY-SA 3.0.
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Mike • Westland Printworks
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