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Welcome to the new site. Here's a thread about the update where you can post your feedback, ask questions or spot those nasty bugs!
More neutral than almost all other gray cards
- Thread starter Doug Kerr
- Start date
Drew Strickland
New member
Nice baiting questions there, counselor.
I'm sure you know "red" is the primary enemy of good skin tone, and this tool works to overcome that.
Drew Strickland
New member
Enough hints, yet?
Doug Kerr
Well-known member
Hi, Drew,
Especially since your weighting coefficients for the MS solution add up to 278 but for the BS solution to 100.
You did mention once that statistics was a specialty of yours, didn't you?
Best regards,
Doug
Especially since your weighting coefficients for the MS solution add up to 278 but for the BS solution to 100.
You did mention once that statistics was a specialty of yours, didn't you?
Best regards,
Doug
Doug Kerr
Well-known member
Doug Kerr
Well-known member
Hi, Drew,
By shifting the chromaticity of the entire image in the red direction? The "hair of the dog that bit you" approach, no doubt.
Or are you speaking of red in the incident illumination being given more emphasis in WB measurement than in actual image recording, leading to an "ideally corrected" image in which skin tones are too bluish?
Best regards,
Doug
By shifting the chromaticity of the entire image in the red direction? The "hair of the dog that bit you" approach, no doubt.
Or are you speaking of red in the incident illumination being given more emphasis in WB measurement than in actual image recording, leading to an "ideally corrected" image in which skin tones are too bluish?
Best regards,
Doug
Drew Strickland
New member
Yes, Doug.
It is all in how you define the problem. That's the point.
The BS position is that S(peed) and E(ease of use) don't exist, or at the very least, don't matter.
Doug Kerr
Well-known member
What ratings! Call Nielsen!
Wow! Over 1000 views. That's more people than watched Ralph Nader interviewed by Charlie Gibson.
Best regards,
Doug
Wow! Over 1000 views. That's more people than watched Ralph Nader interviewed by Charlie Gibson.
Best regards,
Doug
Drew Strickland
New member
Yeah, you'd think I'd be smart enough to spend this much time on this over at pph where there might be some ratings benefit for the operator of that site.
Drew Strickland
New member
Neither.
You're still thinking in the wrong numbers.
Forget about RGB and try CMYK on for size.
We are not adding red, or magenta most of the time.
Is that enough for you?
Drew Strickland
New member
The goal is pleasing. Not accurate.
This entire thread has been an indictment of the notion of "neutral."
Not that neutral doesn't have its place. Just not usually when it comes to skin tones.
This entire thread has been an indictment of the notion of "neutral."
Not that neutral doesn't have its place. Just not usually when it comes to skin tones.
Drew Strickland
New member
Here is a snippet of someone discussing the basic CMY "By the Numbers" method. This tool is only loosely based on these concepts, however, it might perhaps provide a better understanding of what makes up "pleasing" skin tone.
Doug Kerr
Well-known member
Hi, Drew,
It always worked well for Switzerland. But I rarely use it on my Maxima.
I don't understand. What would a "neutral" skin tone be?
Or are you speaking of a neutral target used for white balance color correction, and the corrected skin tones that result from the use of that?
Is the "conclusion" that almost always a color correction shifted from the theoretical one (in the red-yellow direction) will produce "more pleasing" skin tone rendition?
Best regards,
Doug
It always worked well for Switzerland. But I rarely use it on my Maxima.
I don't understand. What would a "neutral" skin tone be?
Or are you speaking of a neutral target used for white balance color correction, and the corrected skin tones that result from the use of that?
Is the "conclusion" that almost always a color correction shifted from the theoretical one (in the red-yellow direction) will produce "more pleasing" skin tone rendition?
Best regards,
Doug
Doug Kerr
Well-known member
Two ol' country boys set out on foot to hunt some rabbit, but there were none to be found, so they headed home early, empty-handed.
On the way, one of them spotted a raccoon's nest in a tree, and he could see little raccoon eyes peering over the edge. "I'm gonna get one of those baby 'coons", he said, "and take him home for my baby brother to play with."
He set down his rifle and shinnied up the tree. Just as he was about to reach into the nest from his temporary perch on a branch, the father raccoon showed up, and he was a big one. He jumped on the guy and a terrible battle ensued.
"Shoot 'im", he screamed to his buddy on the ground.
"I cain't get a clear shot", was the reply.
"Then fire amongst us. One of us has got to get some relief".
So in that vein I retire, for the moment, from this battle of wits (or fractions thereof). I have to go over to the county Democratic Party office and pick up a couple of Hussein signs that at the crack of dawn tomorrow I'll post 101 feet from our precinct polling station.
Now here, accuracy counts.
Best regards,
Doug
On the way, one of them spotted a raccoon's nest in a tree, and he could see little raccoon eyes peering over the edge. "I'm gonna get one of those baby 'coons", he said, "and take him home for my baby brother to play with."
He set down his rifle and shinnied up the tree. Just as he was about to reach into the nest from his temporary perch on a branch, the father raccoon showed up, and he was a big one. He jumped on the guy and a terrible battle ensued.
"Shoot 'im", he screamed to his buddy on the ground.
"I cain't get a clear shot", was the reply.
"Then fire amongst us. One of us has got to get some relief".
So in that vein I retire, for the moment, from this battle of wits (or fractions thereof). I have to go over to the county Democratic Party office and pick up a couple of Hussein signs that at the crack of dawn tomorrow I'll post 101 feet from our precinct polling station.
Now here, accuracy counts.
Best regards,
Doug
Doug Kerr
Well-known member
Hi, Drew,
That's very interesting, and very helpful. Pretty scientific, actually.
Whose essay is that?
In any case, thanks for making it available.
A final comment (consistent with what that piece says, in fact). People wonder what "brown" is from a colorimetric standpoint. Well, broadly speaking, it is more-or-less yellow, of a rather low luminance (or low reflectance, if we're speaking of reflective color).
Best regards,
Doug
That's very interesting, and very helpful. Pretty scientific, actually.
Whose essay is that?
In any case, thanks for making it available.
A final comment (consistent with what that piece says, in fact). People wonder what "brown" is from a colorimetric standpoint. Well, broadly speaking, it is more-or-less yellow, of a rather low luminance (or low reflectance, if we're speaking of reflective color).
Best regards,
Doug
Ben Rubinstein
pro member
1000 views? All me as I read through this stuff again and again and again and I still don't understand a word of it!
Me and math never really got on....
Me and math never really got on....
Doug Kerr
Well-known member
Improving skin tone
Hi, Drew,
Wow! That essay is really useful.
I went to the actual SmugMug piece. It is very enlightening. I suggest that everyone here read it.
Of course the whole matter is sort of complicated, but I get from the discussion these "often-appropriate" guidelines:
1. One key phrase is: "90% of all skin tone complaints come from magenta values being higher than yellow."
The author talks about correcting that. Of course, this process doesn't directly involve change to the Cyan channel. Thus (in the RGB perspective), it does not involve the Red channel.
To me, that says that a change made to overcome this "problem" don't involve shift of the image chromaticity in the Red direction (or the opposite direction).
2. The next point is that the next-most common problem is a wrong Cyan level (of course; that's all that's left!).
The author mainly gives examples of shots in which there is a need to increase the Cyan coordinate. In one example, "Kim is bound to think she looks too pale and too pink." The solution is to increase the Cyan coordinate.
Of course increasing the Cyan coordinate in the CMY color model is identical to decreasing the Red coordinate in the RGB model.
So evidently, what we often need to do to correct this aspect of a skin color problem is to shift the image away from the Red direction. When working in an RGB model, this means motion in the Cyan direction (even though Cyan is not a primary color in the RGB model).
Now, suppose I had some gadget (An offset color target) that would allow me to conveniently move overall image chromaticity in the Red direction while I was doing "white balance" color correction with the eyedropper. This would be, it is said, more convenient than, say, working with the editor color controls.
Well, it doesn't look like I could use it to do any of the things the SmugMug author says would be most likely needed to deal with skin color problems.
Well, that's good to know.
Best regards,
Doug
Hi, Drew,
Wow! That essay is really useful.
I went to the actual SmugMug piece. It is very enlightening. I suggest that everyone here read it.
Of course the whole matter is sort of complicated, but I get from the discussion these "often-appropriate" guidelines:
1. One key phrase is: "90% of all skin tone complaints come from magenta values being higher than yellow."
The author talks about correcting that. Of course, this process doesn't directly involve change to the Cyan channel. Thus (in the RGB perspective), it does not involve the Red channel.
To me, that says that a change made to overcome this "problem" don't involve shift of the image chromaticity in the Red direction (or the opposite direction).
2. The next point is that the next-most common problem is a wrong Cyan level (of course; that's all that's left!).
The author mainly gives examples of shots in which there is a need to increase the Cyan coordinate. In one example, "Kim is bound to think she looks too pale and too pink." The solution is to increase the Cyan coordinate.
Of course increasing the Cyan coordinate in the CMY color model is identical to decreasing the Red coordinate in the RGB model.
So evidently, what we often need to do to correct this aspect of a skin color problem is to shift the image away from the Red direction. When working in an RGB model, this means motion in the Cyan direction (even though Cyan is not a primary color in the RGB model).
Now, suppose I had some gadget (An offset color target) that would allow me to conveniently move overall image chromaticity in the Red direction while I was doing "white balance" color correction with the eyedropper. This would be, it is said, more convenient than, say, working with the editor color controls.
Well, it doesn't look like I could use it to do any of the things the SmugMug author says would be most likely needed to deal with skin color problems.
Well, that's good to know.
Best regards,
Doug
Bart_van_der_Wolf
pro member
Which would happen(?) to correspond to the correction that I applied in my example of skinColor Balance correction (on top of a WB correction). The exact correction that was applied (for my specific camera, a 1Ds3) was 15 Cyan (minus Red) and 6 Blue ...
Bart
Drew Strickland
New member
Glad you see the value in the science behind the tool, finally.
You may want to look again, and actually test one.
Here is a recent exchange I had with the gentleman who wrote the above piece you enjoyed.
Doug Kerr
Well-known member
Hi, Drew,
Well, to me, it didn't seem to be behind this tool at all - just the opposite.
The author's overall theme is in fact consistent with your recent comment that "'red' is the primary enemy of good skin tone".
That's why I'm surprised that the ColorRight MAX apparently only allows shifting the chromaticity of the image in the Yellow-Red direction.
What am I missing here?
Thanks.
Best regards,
Doug
Well, to me, it didn't seem to be behind this tool at all - just the opposite.
The author's overall theme is in fact consistent with your recent comment that "'red' is the primary enemy of good skin tone".
That's why I'm surprised that the ColorRight MAX apparently only allows shifting the chromaticity of the image in the Yellow-Red direction.
What am I missing here?
Thanks.
Best regards,
Doug
Drew Strickland
New member
If you want to get a little clearer on the details get the books linked above.
Chapter 4 of "skin" by Lee Varis is especially useful. If you like to "roll your own" curves, he lays it out in detail for you. Chapter 3 of Professional Photoshop by Dan Margulis will provide even more background.
Of course, none of this changes the basic equations I provided above.
For (S)peed and (E)ase of Use you will find the ColorRight MAX to be an invaluable tool for getting you to your destination of proper CMYK ratios.
Chapter 4 of "skin" by Lee Varis is especially useful. If you like to "roll your own" curves, he lays it out in detail for you. Chapter 3 of Professional Photoshop by Dan Margulis will provide even more background.
Of course, none of this changes the basic equations I provided above.
For (S)peed and (E)ase of Use you will find the ColorRight MAX to be an invaluable tool for getting you to your destination of proper CMYK ratios.
Doug Kerr
Well-known member
Hi, Drew,
I particularly like the way it can fix up problems in "K".
Best regards,
Doug
I particularly like the way it can fix up problems in "K".
Best regards,
Doug
Drew Strickland
New member
1000 views? All me as I read through this stuff again and again and again and I still don't understand a word of it!
Me and math never really got on....
Sorry, Ben. I tried to keep it less technical. That really is the whole point of the tool.
To provide 98% of the benefit with 1/10th the work.
In reality, I think the purists should embrace these tools as providing a gateway for people to understand what their cameras and software are truly capable of.
The more people that see what is possible, the more likely it is that will be willing to spend more time on a few images that really may benefit from the "perfect or else" approach.
Drew Strickland
New member
Hey, don't poke fun at "Special K."
From Margulis in Professional Photoshop.
"It would be a sad world if we had to print without black ink."
and
"In RGB, all colors are unique; they can be created in only one way. CMYK usually offers many different possible formulations."
and
"Black expands our gamut."
Drew Strickland
New member
I think Bart has nailed it here. When variables such as (S)peed and (E)ase of Use matter, even just a little bit, a tool made to improve the process is in order.
When (Q)uality is of absolute paramount importance and time is of little to no essence, then the extra 2% you may get out of a local correction may be worth it.
e.g., a competition or museum piece.
They both have their place and I will be happy to spread the long form scientific knowledge along with the short form tool.
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Drew Strickland
New member
I guess a system of finding out how to measure CMY values in an image.
Below are two samples.
The first shows representative CMY ratio values when using a neutral wb rendering.
The second shows the CMY ratios when clicking MAX patch #4.
This one of the raw images available for download earlier in the thread.
Drew Strickland
New member
Hey Bart,
Sorry about the whole BS thing. I didn't realize it would come across that way when I was first thinking up the equation, seriously.
But, then I just ran with it. Not very "charitable." Sorry.
Sorry about the whole BS thing. I didn't realize it would come across that way when I was first thinking up the equation, seriously.
But, then I just ran with it. Not very "charitable." Sorry.
Will Thompson
Well Known Member
Drew! You might want to refrain from using above to refer to an earlier post since not all users display older posts first. I always use most recent first so when you do you are referring to a post that may not yet exist!
Cem_Usakligil
Well-known member
Hi Drew,
Not having read the posts since yesterday, my first thought here was that you were referring to male bovine excrement when you wrote BS. In case somebody else might the same mistake as I did, here in full ;-):
BS = Bart's Solution
Cheers,
Doug Kerr
Well-known member
Hi, Drew,
I had asked, "What am I missing". Your reply was:
No, that's not what I am missing. (But thanks for showing me how to do it.)
Let me encapsulate the paradox I referred to:
1. The SmugMug article suggests that often, to attain a "pleasing" skin tone, we will need to increase the Cyan coordinate of the skin color description (which directly corresponds to a reduction in the Red coordinate if we think of the corresponding RGB representation). (I assume K is 0 here.)
2. You have said that "Red is the enemy of nice skin tone" (I paraphrase).
These two admittedly-broad generalizations seem to fit together.
Now a derived point:
3. Therefore, in "improving" skin tones, we will most often need to increase the Cyan coordinate (that is, decrease the Red coordinate).
Now the tricky one:
4. By using a non-neutral patch of the ColorRight MAX as the reference when doing white balance color correction, we can shift the chromaticity of all scene colors in the Yellow-Red direction (only).
Now, I ask again: What am I missing?
Now, regarding your examples of applying an "adjustment" to the image of Melissa, we note that using a "Patch 4" shift, the C coordinate is indeed decreased (not increased, as common wisdom suggests), and of course the R coordinate is increased (not much of a victory over the "enemy" you mention).
But the shift does make M less than Y, which we also hear it should be for a pleasing result. And certainly the result in the example is pleasing.
But it doesn't fit the simplistic aphorisms about Cyan and Red.
Thanks.
Best regards,
Doug
I had asked, "What am I missing". Your reply was:
No, that's not what I am missing. (But thanks for showing me how to do it.)
Let me encapsulate the paradox I referred to:
1. The SmugMug article suggests that often, to attain a "pleasing" skin tone, we will need to increase the Cyan coordinate of the skin color description (which directly corresponds to a reduction in the Red coordinate if we think of the corresponding RGB representation). (I assume K is 0 here.)
2. You have said that "Red is the enemy of nice skin tone" (I paraphrase).
These two admittedly-broad generalizations seem to fit together.
Now a derived point:
3. Therefore, in "improving" skin tones, we will most often need to increase the Cyan coordinate (that is, decrease the Red coordinate).
Now the tricky one:
4. By using a non-neutral patch of the ColorRight MAX as the reference when doing white balance color correction, we can shift the chromaticity of all scene colors in the Yellow-Red direction (only).
Now, I ask again: What am I missing?
Now, regarding your examples of applying an "adjustment" to the image of Melissa, we note that using a "Patch 4" shift, the C coordinate is indeed decreased (not increased, as common wisdom suggests), and of course the R coordinate is increased (not much of a victory over the "enemy" you mention).
But the shift does make M less than Y, which we also hear it should be for a pleasing result. And certainly the result in the example is pleasing.
But it doesn't fit the simplistic aphorisms about Cyan and Red.
Thanks.
Best regards,
Doug
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