Oversaturation in sRGB

[Lorant Voros]

A year ago Arti and I had a great conversation about oversatuating my flamingo images where the conclusion was to get it right in the field. http://www.birdphotographers.net/for...ad.php?t=44515

This year I made sure my exposure is right. However, for web use we convert to sRGB and the images that would otherwise be good for printing get badly oversaturated.
I usually select sRGB format in ACR and try to manage the blown reds with the combination of the recovery slider and in the HSL/Grayscale I set in the Saturation and Luminance the Reds and Oranges to -10. If I still have blown parts I go to the adjustment brush and I tone down the images where I need to.

This image still has oversaturated pixels (actually many) due to the size reduction and the additional sharpening in Photoshop, but the color is very close to the real color of the flamingo.

With this method I can get rid of all the oversaturated parts and pixels, however, the color will not be like what I saw out in the field.

I am asking those Photoshop gurus on BPN if there is a different and better approach to this problem. I am sure many of us on this forum would benefit from the advice.

Thanks,

Lorant

[Lorant Voros]

Actually I meant to post this to Tutorials and Educational Resources. Maybe one of the Moderators would be so kind to move the thread:-). Unless it is the right place for this kind of topics. Thank you.

[Harold Davis]

i think you may get your answer here, lorant. big congrats on getting it right in the camera. this is awesome!! just might clone out the sand line at the top if you see fit.

[Alfred Forns]

Hi Lorant

Read the thread and basically it is normal for the sensor to oversaturate that color, just needs to be tone down. As you desaturate the color look for detail to start coming back to the reds !!

btw what is your in camera setting for color space? Best to use sRBG since pixels will be blown sooner (narrower space) and image will show more true to form in the camera LCD, converting you can switch to Adobe RGB 1998 This will allow you to push to the edge without going over.

Image quality wise you should see no difference when posting for web. How big a crop is this one? From the large dof looks like a good size crop. Do like the image as presented and colors looks just fine. You should not be getting those variations when converting and posting, would check your settings in PS for proof set up?

[Lorant Voros]

Al,

Thank you for getting back to me. My color space was set to RGB. There is a big difference between sRGB and RGB if we are looking at these sensitive colors like Red and Yellow. I am glad you like the example..as you can see I didn't crop much. Here is the unedited image in ACR, one is sRGB the other is RGB color space. I took this photo with diffused light by the clouds, but I have others when the sun came out. Those are good in RGB and almost beyond help in sRGB. I'd like to hear some more of this setting of PS proof set up. Can you explain?
Cheers.

[Desmond Chan]

If I just want to tone down the red in jpeg, I'd select the "brightest" red spot and adjust the red channel in Curves.

I switch to sRGB at the last moment but before sharpening. In ACR, I use ProPhoto RGB.

[Alfred Forns]

Hi Lorant Would go in PS to view>proof and set to monitor RBG Will match posted images to monitor. Toggle through the settings to see the difference.

Thanks Desmond Imagine that converting to ProPhotoRGB would be best since it has the widest color space, I have been doing the same also just not sure what is able to take advantage.

[Lorant Voros]

If I just want to tone down the red in jpeg, I'd select the "brightest" red spot and adjust the red channel in Curves.

I switch to sRGB at the last moment but before sharpening. In ACR, I use ProPhoto RGB.

Desmond. Thanks for the suggestion. I would need to know exactly how you tone down the Red in Curves. I followed your workflow and I am just before sharpening. i go to Edit, Convert to profile, sRGB. At this moment I cut the Red chanel, that means that info doesn't exist anymore. The brightest spot in Red is all the way on the right side of the histogram and it is cut. I don't know how I can recover it in Curves. Can you explain?
Lorant

[Lorant Voros]

Hi Lorant Would go in PS to view>proof and set to monitor RBG Will match posted images to monitor. Toggle through the settings to see the difference.

\.

Thanks Al...I got it and it is done. Hope it will help in the future :-). Thanks for your email too.

[Jeff Cashdollar]

Lorant,

Would you consider summarizing the issues and remedy in a workflow type narrative (succinctly) - I will talk with James about moving the thread to the Ed Forum for all to leverage.

Send me a PM and we can discuss in more detail - thanks.

[Desmond Chan]

At this moment I cut the Red chanel, that means that info doesn't exist anymore.

Agreed. Once it's 255, there's no detail to recover.

The brightest spot in Red is all the way on the right side of the histogram and it is cut. I don't know how I can recover it in Curves. Can you explain?

What I'd do is I'd use the eye-dropper tool and click on the spot with the brightest red (in your case it would be right at the very top right hand corner of the curve, right-hand side of the curve being the bright side). Then I'd tap on the down-arrow key on the keyboard. You should see that the red channel number goes down from 255, 254, 253, etc. What it does is - my understanding - it simply tones down the brightness/contrast; it does not give you any details because there's none to begin with. The other way is to pick that particular channel you want to adjust in Levels and adjust the output levels slider (the first one from the bottom). It should give the same result. If necessarily, I would brush in the mask that comes with the adjustment layer to hide areas that I don't want to be affected by the adjustment.

I just learned another way to deal with brown highlights using LAB yesterday. It seems to me is cloning done in LAB.

[Lorant Voros]

Agreed. Once it's 255, there's no detail to recover.

What I'd do is I'd use the eye-dropper tool and click on the spot with the brightest red (in your case it would be right at the very top right hand corner of the curve, right-hand side of the curve being the bright side). Then I'd tap on the down-arrow key on the keyboard. You should see that the red channel number goes down from 255, 254, 253, etc. What it does is - my understanding - it simply tones down the brightness/contrast; it does not give you any details because there's none to begin with. The other way is to pick that particular channel you want to adjust in Levels and adjust the output levels slider (the first one from the bottom). It should give the same result. If necessarily, I would brush in the mask that comes with the adjustment layer to hide areas that I don't want to be affected by the adjustment.

I just learned another way to deal with brown highlights using LAB yesterday. It seems to me is cloning done in LAB.

Thanks a lot for this. I think I got it. :-). I used the Levels output reduction. I will play with it and post something soon.

Cheers.

Lorant

[arash_hazeghi]

Lorant,
I think by RGB you mean photoPro RGB? Answer is simple, PhotoPro RGB has a wider gamut of colors especially in the reds, these colors cannot be displayed in sRGB mode because they do not exist in its gamut!!! Therefore they will be mapped to the corner of the sRGB triangle in the diagram above, this means they will be clipped at 255 level. no amount of toning down will help after the conversion to sRGB JPEG because the channel is clipped and has no information left in those tones.
You have to make sure all the colors are inside the sRGB triangle BEFORE converting to sRGB, so tone down the reds to bring them within the sRGB limits before changing profile. Alternatively you can set your working space to sRGB or Adobe RGB so that you don't have to worry about this issue. I use sRGB for web (not all browsers are color smart) and Adobe RGB for print.

Hope this helps

[Alfred Forns]

Jeff the thread is doing fine right here and I can move it myself. After replies slow down will be moved.

[Lorant Voros]

Lorant,
I think by RGB you mean photoPro RGB? Answer is simple, PhotoPro RGB has a wider gamut of colors especially in the reds, these colors cannot be displayed in sRGB mode because they do not exist in its gamut!!! Therefore they will be mapped to the corner of the sRGB triangle in the diagram above, this means they will be clipped at 255 level. no amount of toning down will help after the conversion to sRGB JPEG because the channel is clipped and has no information left in those tones.
You have to make sure all the colors are inside the sRGB triangle BEFORE converting to sRGB, so tone down the reds to bring them within the sRGB limits before changing profile. Alternatively you can set your working space to sRGB or Adobe RGB so that you don't have to worry about this issue. I use sRGB for web (not all browsers are color smart) and Adobe RGB for print.

Hope this helps

Arash. Thanks for joining the topic.

I totally agree. At least that was my understanding, but your triangle is a very good way to explain and thank you very much for the visualization. I actually meant RGB, since my camera was set to RGB color mode and the colors aren’t blown. It does changes in sRGB looking at the triangle and reading your explanation we know why :-).
With the workflow that I mentioned above I can eliminate the highlights and have all the details, however, the photo will look very strange. With the workflow suggested by Desmond maybe we loose detail, since it doesn’t exist in sRGB mode, but the image looks more natural.

Do you have a suggested workflow that would eliminate the highlights before the conversion to sRGB and still saves the details?

Lorant

[Dave Leroy]

This is a very informative thread and thanks for starting it Lorant.

Although I have seen the color gamut chart as posted by Arash many times, it really sinks in what happens when I see it in combination with real examples.

Very nice photo Lorant. Composition and pose is bang on.

[arash_hazeghi]

Arash. Thanks for joining the topic.

I totally agree. At least that was my understanding, but your triangle is a very good way to explain and thank you very much for the visualization. I actually meant RGB, since my camera was set to RGB color mode and the colors aren’t blown. It does changes in sRGB looking at the triangle and reading your explanation we know why :-).
With the workflow that I mentioned above I can eliminate the highlights and have all the details, however, the photo will look very strange. With the workflow suggested by Desmond maybe we loose detail, since it doesn’t exist in sRGB mode, but the image looks more natural.

Do you have a suggested workflow that would eliminate the highlights before the conversion to sRGB and still saves the details?

Lorant

Hi Lorant,
I am not sure what you mean by "RGB", My cameras (5D and MKIV) do not have a "RGB" mode, they have Adobe RGB or sRGB, what kind of camera are you using?


Arash

[Lorant Voros]

Hi Lorant,
I am not sure what you mean by "RGB", My cameras (5D and MKIV) do not have a "RGB" mode, they have Adobe RGB or sRGB, what kind of camera are you using?


Arash

Sorry Arash. What I meant is Adobe RGB. Not ProPhoto RGB. I am using a 1DMKIII.
Lorant

[arash_hazeghi]

Sorry Arash. What I meant is Adobe RGB. Not ProPhoto RGB. I am using a 1DMKIII.
Lorant

That is a bit strange because sRGB and RGB don't differ much in the reds, but maybe the reds in the flamingo are so extreme that the small difference matters here, which means the reds in original are close to being hot. I would just tone down the reds in the original by lowering the EC value so that the red channel is not pushed all the way to the right in the histogram. then convert to sRGB and adjust brightness if needed, this should shift the reds but keep all the information (details)

Best

[Lorant Voros]

Arash,

I guess the Red is extreme with the flamingos. I normally like to overexpose my images a tiny bit, since it is easier to deal with the little highlight than recover the details in the blacks without increasing noise. With a gentle oversaturation in Adobe RGB more I go extreme in sRGB conversion. Simply pulling the Exposure slider to the left and pulling the Recovery slider to the right don’t help. What helps is the workflow mentioned all the way up, but the result is strange. I can post an example if you wish.

[arash_hazeghi]

Arash,

I guess the Red is extreme with the flamingos. I normally like to overexpose my images a tiny bit, since it is easier to deal with the little highlight than recover the details in the blacks without increasing noise. With a gentle oversaturation in Adobe RGB more I go extreme in sRGB conversion. Simply pulling the Exposure slider to the left and pulling the Recovery slider to the right don’t help. What helps is the workflow mentioned all the way up, but the result is strange. I can post an example if you wish.

Overexposing is the reason you get blown reds, I take a completely different approach at first place but if you want email me the RAW file and I will see what can be done to correct this without artifacts.

Best

[Axel Hildebrandt]

With bright reds when working in Adobe RGB, I try to process them in a way that there is enough leverage when converting to sRGB. In other words, make sure the reds are not too close to 255.

Sometimes I wonder if it wouldn't make more sense to leave it in Adobe RGB since it has a wider gamut and most modern browsers are color-managed, at least Firefox and Safari are.

[Michael Gerald-Yamasaki]

Folks,

Greetings. Have you ever asked yourself what color space is represented in the histogram? The answer to this question is part of the problem. I once knew the answer but have since forgotten and it may have changed. Not too long ago LR and PS were using different color spaces to create their respective histograms. Sigh. It's all a pile of knots.

What is not yet mentioned here is the rendering intents for conversions between color spaces (see conversion options in Convert to Profile dialog). Another pile of, er, knots.

But, the good news is this can be headed off for the most part before getting into color spaces. Color space assignment should not for the most part be noticeable on screen! Unless you have a monitor that is 100% aRGB (you would have had to have gone out of your way and spent more than a few bucks to have such a monitor).

The place to make these adjustments is in raw conversion: white balance, recovery, exposure adjustments, etc. In this current example, the reds should not be pushed all the way to the right (and beyond). A good comfortable number to shoot for is 240 (IMO, higher numbers lose color resolution. For instance, how many colors are there at minimum value 254 (answer is 6, for 8 bits plus 2 grays) only one red [255, 254, 254]).

The way to the right reds here is (IMO) less exposure. The blacks are a problem for this bird (requiring bright light and raw conversion management).

Cheers,

-Michael-

[Alfred Forns]

Axel that would be a good idea but not everyone uses those browsers !!!

[Lorant Voros]

Overexposing is the reason you get blown reds, I take a completely different approach at first place but if you want email me the RAW file and I will see what can be done to correct this without artifacts.

Best

Genrally overexposing a tiny bit works for me. I can simply recover the highlights with the Recovery slider and I have more detail in the blacks. But even a perfectly exposed Adobe RGB color profiled flamingo image will be badly oversaturated in sRGB after the conversion if there was a little sun on the bird.
I sent you a mail in BPN. I can send you a RAW file; send me your email address.
Lorant

[arash_hazeghi]

Sorry I did not have time to do this earlier, here is my try

The red channel in RAW is very hot and pretty close to saturation but fortunately it is not clipped. Here is what I did

open in DPP

lower exposure by 0.8EV
highlight recover -2
saturation -2
transfer to photoshop
convert to sRGB (relative colorimetric)
highlight and shadow to brighten the sky a tad
done

hope you like it

[arash_hazeghi]

And here is the result. you can brighten more if the sky is still too dark.