The Mystery Of Tetrachromacy (color vision stuff)

[Alan Klein]

Jim:  I'm sure you're right.  There are certainly issues with flesh tones in films like Velvia and Ektar so you should shoot Portra.  The point I was making in my previous post was to forget trying to match the original object color.  Trust the perception of your eyes and brain.  Unless you have some abnormality, most people will agree with your interpretation of colors.  There's no point trying to match the original color unless you're doing pictures of clothes or other products where the the manufacturer needs the colors to match what they're showing let's say in a brochure.   Of course the "munki" is important to make sure your monitor is initially calibrated to "real" base-line color.  Otherwise your eyes will adjust to color parameters that won't match what is "seen" in other monitors.   

I'm editing the original quote to make more sense:

Jim:  I'm sure you're right.  There are certainly issues with flesh tones in films like Velvia and Ektar so you should shoot Portra.  The point I was making in my previous post was to forget trying to match the original object color.  Trust the perception of your eyes and brain.  Unless you have some abnormality, most people will agree with your interpretation of colors.   Of course the "munki" is important to make sure your monitor is initially calibrated to "real" base-line color.  Otherwise your eyes will adjust the color in post processing to parameters that won't match what is "seen" in other monitors. 

There's no point trying to match the original color unless you're doing pictures of clothes or other products where the the manufacturer needs the colors to match what they're showing let's say in a brochure. 

[Rob C]

I'm editing the original quote to make more sense:

Jim:  I'm sure you're right.  There are certainly issues with flesh tones in films like Velvia and Ektar so you should shoot Portra.  The point I was making in my previous post was to forget trying to match the original object color.  Trust the perception of your eyes and brain.  Unless you have some abnormality, most people will agree with your interpretation of colors.   Of course the "munki" is important to make sure your monitor is initially calibrated to "real" base-line color.  Otherwise your eyes will adjust the color in post processing to parameters that won't match what is "seen" in other monitors. 

There's no point trying to match the original color unless you're doing pictures of clothes or other products where the the manufacturer needs the colors to match what they're showing let's say in a brochure.

Had an experience once shooting on 120 Ektachrome with studio flash, white background and walls. The subject was leather coats, one a pale green and the other a pale blue. On the trannies they were indistinguishable. The only way we could separate them and tell which had been which was by noting the different buttons.

Perhaps Kodak though them both cyan...

Rob C

[amolitor]

Yeah, in the commercial world where you're trying to make the logo or the shampoo bottle or whatever look correct under a meaningful range of conditions, heaven and earth are, in general, moved. With varying results, but consistently high costs!

The house paint guys seem to have a surprising amount of this stuff solved quite well, which is a moderately surreal experience.

[Jim Kasson]

Had an experience once shooting on 120 Ektachrome with studio flash, white background and walls. The subject was leather coats, one a pale green and the other a pale blue. On the trannies they were indistinguishable. The only way we could separate them and tell which had been which was by noting the different buttons.

Perhaps Kodak though them both cyan...

Rob C

Some dyes reflect strongly in IR. Many films are sensitive to IR.  Another source of color error, especially in clothing.

Jim

[Telecaster]

Of course the "munki" is important to make sure your monitor is initially calibrated to "real" base-line color. Otherwise your eyes will adjust the color in post processing to parameters that won't match what is "seen" in other monitors.

Yes, IMO this is where the value in "color management" lies. In theory it should put everyone on the same playing field. (In practice the situation is messy but better than chaotic.) Beyond that, the game you choose to play is up to you. 

-Dave-

[Jim Kasson]

Spectral color reproduction, in which the reproduction, on a pixel-by-pixel basis, contains the same spectral power distributions or reflectance spectra as the original.

This is the only one of Hunt's set of reproduction objectives that will result in guaranteed color matching for tetrachromats and trichromats. It wil also provide color matching for color deficient observers.

That's the good news.

The bad news is that it is completely impractical, except in very limited cases.

Jim

[Telecaster]

Some dyes reflect strongly in IR. Many films are sensitive to IR.  Another source of color error, especially in clothing.

Of course "color error" is entirely subjective. If you're a creature with light detectors of the same spectral sensitivity as Rob's Ektachrome, then it is our eye/brain system that's in error. 

-Dave-

[digitaldog]

It all comes back around to 'what problem, exactly, am I solving with this color munki I just bought?' And the answer is remarkably murky. If you're charging real money you should at least be able to explain what you're selling.

What it does is rather simple, I'm shocked (again) by your misunderstandings and biased view of a technology you don't appear to understand. It's a measuring device matted with software to define device values for the creation of an ICC Profile. As I told you ages ago, digital color management is number management.
You kind of sound like someone who tells other's he is a carpenter, that a tape measure is and measurements are BS and have no idea why you purchased one.
X-rite has provided plenty of text, some marketing hype, much accurate information about what the product does and what problem's it solves:

http://xritephoto.com/ph_product_overview.aspx?ID=1115

X-Rite ColorMunki Photo is an all-in-one color control solution that provides complete control over calibrating your cameras, monitors, projectors and printers. Our wizard-driven software provides the perfect balance of automation with a full range of creative controls for photographers looking for more control over their color.
http://xritephoto.com/ph_product_overview.aspx?ID=1115:
All-in-One spectrophotometer is the only device required to profile monitors, projectors and printers and measure colors.

[amolitor]

I know what it does. I even, secretly, know what problems it can be used to solve.

I am waiting, in vain, for you to clearly articulate any one of those problems. Well. I'm not. I'm talking to some other folks now.

[Jim Kasson]

Of course "color error" is entirely subjective. If you're a creature with light detectors of the same spectral sensitivity as Rob's Ektachrome, then it is our eye/brain system that's in error. 

-Dave-

I was referring to metameric capture error.

http://blog.kasson.com/?p=12504

I apologize if, in my refraining from the technical term, I sewed confusion.

Of course, the term assumes color normalcy, which, while normal, is not universal. It completely ignores viewing conditions and spatial effects, which Andrew R has pointed out as well.

Jim

[Jim Kasson]

I know what it does. I even, secretly, know what problems it can be used to solve.

I am waiting, in vain, for you to clearly articulate any one of those problems.

Do you really want to go back to scanners that sell for six figures, are covered with knobs, and take two or three years to learn how to use?

Or maybe do it with a PC so it's cheap, but still have to rescan every time the printer changes? You'd still need all the skill, since gamut mapping would be manual and individual for every image. You'd also have to figure out the scanner primaries, the printer ink mixing color effects (Kubelka-Munk, anyone?), undercover removal, gray component replacement, max ink loading, and all that printer stuff.

Jim

[amolitor]

Good heavens, no, Jim. That sounds horrible.

You seem to be a fine fellow, and I'm finding what you say to be both interesting and informative. I do know what a color munki does, I promise, and I do have some grasp on the problems that can be solved with the technologies. And neither those problems nor those solutions are to be sneezed at, they are not trivial at all. There is real value, real utility, here. And that value is actually pretty hard to articulate to lay people.

My issue is that the problems solved by color management are not, as a rule, the problems that lay people who buy color munkis and the like think they solve. I have quite seriously seen people (many of them) who believe that because their workflow is color managed, that they are producing natural looking skin tones. They believe that simply turning on the color management checkbox and building profiles for everything in sight will automatically produce "the right" results, when that isn't even a meaningful idea. When someone points out that all the people in their pictures appear to have been boiled, they quote back RGB numbers and charts which tell them what RGB numbers are in-range for flesh tones. Given that this latter step is completely meaningless (I don't even know where these charts could have come from) I can tell you for sure that the marketing of color management solutions is producing some fairly weird results out there in the real world.

Now, these people are not geniuses, obviously. There are a lot of dunces in the world. But the dunces are getting these weird ideas from somewhere.

Consumer-grade color management is a real system that solves real problems which is, in spite of all that, being sold, purchased, and used, in much the same ways patent medicines were 150 years ago. That's a shame. That's a problem.

This thread, with respect to those of you actually trying to contribute information, is an excellent illustration of why.

[digitaldog]

I'm not. I'm talking to some other folks now.

Good for you, a bit of a pity for them. 

My issue is that the problems solved by color management are not, as a rule, the problems that lay people who buy color munkis and the like think they solve.

Speaking for others, poorly again.

This thread, with respect to those of you actually trying to contribute information, is an excellent illustration of why.

There's really only one person writing here who is clearly confused and providing excellent evidence of it.

[Telecaster]

My issue is that the problems solved by color management are not, as a rule, the problems that lay people who buy color munkis and the like think they solve. I have quite seriously seen people (many of them) who believe that because their workflow is color managed, that they are producing natural looking skin tones. They believe that simply turning on the color management checkbox and building profiles for everything in sight will automatically produce "the right" results, when that isn't even a meaningful idea. When someone points out that all the people in their pictures appear to have been boiled, they quote back RGB numbers and charts which tell them what RGB numbers are in-range for flesh tones.

As I have no experience with people who believe as you describe, I have to admit I'm kinda nonplussed by much of your argument in this thread. Imagine the following declaration: "There are actually people who believe the earth is flat! And the existence of 2D maps just plays into their delusion!" How to respond other than: "Uh, okay. Maybe so… (shrug)"

-Dave-

[amolitor]

That seems like a fair point.

I think, however, there is perhaps a bit of daylight between '2d maps' and the sort of hype and jargon color management suffers under.

[digitaldog]

I think, however, there is perhaps a bit of daylight between '2d maps' and the sort of hype and jargon color management suffers under.

Or the hype of crusaders who don't know a lick about color management.

[amolitor]

It's OK. You've established that you don't like me.

You can rest now, big guy.

[digitaldog]

It's OK. You've established that you don't like me.

That's absurd. Like most of your writings here. I don't know you, I have no opinion other than your silly text in this thread! It's a paper trail that's rather clear and makes you look rather foolish. Need the distillation in one place? Here goes. You're doing a fine job of digging yourself into a hole, I don't see anyone coming to your defense for good reason. 


Your very first post here was your admission to a crusade you tell us is based on color management being BS: Also, more grist for my little personal crusade to the effect that color management is mostly BS.



Then you contradict yourself in two sentences next to each other:
Possibly I had appearance and perception reversed but we are in angels on pinheads territory at this point. Yes yes it's a super important distinction. It always it is.


Then you admit you can't color manage output to a printer:
You need an apple, a color managed workflow to print, and ten friends. I have the first and the last, but not the middle one.


Then you write for others when it's clear you're speaking for yourself, an average rube to color management apparently:
Since this is precisely what the average rube thinks his new color munki spyder thing is supposed to do for him, and adding to that the fact that experts become surprisingly evasive when asked these sorts of simple questions, perhaps one can begin to understand my position.


Then a statement that doesn't make any sense and when asked to further explain, you don't:
The metrics we use in perceptual color spaces agree pretty well with the real world, and are technically achievable, with effort.


Then, with all the text proving you don't understand the subject, imply that you purcahsed something and got fooled by the company producing the product:
It all comes back around to 'what problem, exactly, am I solving with this color munki I just bought?' And the answer is remarkably murky. If you're charging real money you should at least be able to explain what you're selling.


Then you again contradict your own writing by stating:
I know what it does. I even, secretly, know what problems it can be used to solve.

I don't dislike you one bit. I have zero respect for your rants and writing or understanding of the topic and think you're the last person here who should be on any crusade, pro or con, involving color management!

[Telecaster]

From physicist Brian Cox on Twitter a few hours ago:

"Some flat earth person just tweeted me arguing that space flight is faked because of the Van Halen belts… Rock n Roll :-)"

Attached: a pic of the Van Halen belt. 

-Dave-

[amolitor]

For reference, I don't use a color managed process not because I incapable of doing so, but because I have no need of such a thing. I do not have any of the problems it solves.

Van Halen belts explain many of the mysteries of the universe. But, strangely enough, not why some people think the Sammy Hagar era was OK. That mystery appears to be incapable of explanation.

Edit: fixed typo. Thanks Rod!