attention color whizes: non-typical sRGB/RGB/ProPhoto question

[tgray]

This entire argument boils down to adaptation.  If you use adaptation, the blue is within Pro Photo, and if you don’t then it isn’t (or if you simply mess it up because you don’t realize what you’re doing on the calculator.)

Yay! We have a winner.

Again, not to put words in joofa's mouth, but I don't think he ever said, "I don't care about adaptation."  I think he was pointing out the case where you don't use it, as in his #1 of 4 cases.  Later, others put forth the idea that using adaptation is not always the 'right' way to do things, though the examples have been vague.

At least that's how I've understood this discussion.

[MarkM]

This entire argument boils down to adaptation.  If you use adaptation, the blue is within Pro Photo, and if you don’t then it isn’t (or if you simply mess it up because you don’t realize what you’re doing on the calculator.)

Yes, you are 100% correct. I could demonstrate that on Joofa's own graph, but it's pointless because he does not want to commit to the method he is using. If I took the time to make a graph demonstrating this, he would simply say it isn't correct without further explanation. In other words it's a waste of time.

[joofa]

Yay! We have a winner.

Again, not to put words in joofa's mouth, but I don't think he ever said, "I don't care about adaptation."  I think he was pointing out the case where you don't use it, as in his #1 of 4 cases.  Later, others put forth the idea that using adaptation is not always the 'right' way to do things, though the examples have been vague.

At least that's how I've understood this discussion.

TGray, you are a sane voice here. Please help me with others. BTW, I did note that tho_mas apparently found that when going from Prophoto RGB (D50)->Adobe RGB (D65), both abscol and relcol with adaption will be out of gamut. Right tho_mas? So apparently relcol is not always working.

Joofa

[joofa]

Yes, you are 100% correct. I could demonstrate that on Joofa's own graph, but it's pointless because he does not want to commit to the method he is using. If I took the time to make a graph demonstrating this, he would simply say it isn't correct without further explanation. In other words it's a waste of time.

I don't know why you are after my methods. I repeat again, Iliah Borg, Peter (DPL), and JC1 have also independently confirmed what I said regarding case (1). If they can do it why can't you?

Joofa

[tho_mas]

BTW, I did note that tho_mas apparently found that when going from Prophoto RGB (D50)->Adobe RGB (D65), both abscol and relcol with adaption will be out of gamut. Right tho_mas? So apparently relcol is not always working.

what?
What I have shown to you is that ALL saturated blues of ProPhoto clip in AdobeRGB when converting either relcol or abscol. Which shows that AdobeRGB does NOT contain a single blue value that is outside of ProPhoto (otherwise the respective value would NOT show clipping).

"relcol is not always working" ... is a strange way to discribe this. In relcol colors of the source color space that are out of gamut of the target color space are clipped to the outer edges of the target gamut.
Now... convert ProPhoto RGB 0/0/255 relcol to AdobeRGB and plot that values in your strange software. You will find that it is exactly the highest saturated blue of AdobeRGB (D65!). How that when AdobeRGB contains higher saturated blues than ProPhoto (supposedly)? How can ProPhoto produce a blue that matches the highest saturated blue in AdobeRGB?

[jeremypayne]

Gosh, all effort in vain. Conceptually, there is NO difference between Prophoto RGB (D50) and Prophoto RGB (D65), both can be conceived with the same exact thought!

Joofa

Is prophoto RGB (D50) contained within prophoto (D65)?

PS What is a color?

[joofa]

How that when AdobeRGB contains higher saturated blues than ProPhoto (supposedly)? How can ProPhoto produce a blue that matches the highest saturated blue in AdobeRGB?

tho_mas, I think I already gave you an answer a number of times. How hard it is to imagine that both Adobe RGB (D65) and Prophoto RGB (D50) contains colors that are outside each others gamuts. In fact, what you have found out is that going Prophoto RGB (D50)->Adobe RGB (D65) is even more messed up as it clips in both ways: abscol or relcol. So this is a stronger case than Adobe RGB (D65)->Prophoto RGB (D50).

If you ask me again why, then please read my recent messages to you again.

Guys, it is getting very repititious. If TGray can understand things perfectly, what is happening to you?

Sincerely,

Joofa

[jeremypayne]

tho_mas, I think I already gave you an answer a number of times. How hard it is to imagine that both Adobe RGB (D65) and Prophoto RGB (D50) contains colors that are outside each others gamuts. In fact, what you have found out is that going Prophoto RGB (D50)->Adobe RGB (D65) is even more messed up as it clips in both ways: abscol or relcol. So this is a stronger case than Adobe RGB (D65)->Prophoto RGB (D50).

If you ask me again why, then please read my recent messages to you again.

Guys, it is getting very repititious. If TGray can understand things perfectly, what is happening to you guys?

Sincerely,

Joofa

Numbers without meaning ... are ... numbers.

Can you define a color?  'cause if you can't, you have said nothing more than "2 is greater than 1".

[Graystar]

I think he was pointing out the case where you don't use it, as in his #1 of 4 cases.

Right.  And what he's failing to realize is that those cases have no meaning whatsoever.

I already gave an analogy with temperature conversion.  There's 1.8 F to every 1 C.  So to convert C to F you multiply by 1.8.  But you also have to consider the freezing point of water.  So you have to add 32 to the result to get the actual F temperature that is physically the same as the C temperature.

In Joofa’s #1 and #4 cases, it’s like he’s forgetting about the 32, and then proclaiming that the two temperatures are the same.  That’s wrong.  The temperatures aren’t the same, and neither are the blues in his calculations.

[tho_mas]

Guys, it is getting very repititious. If TGray can understand things perfectly, what is happening to you guys?

I have no trouble to understand that D50 is not D65.
ProPhoto's white is not contained in AdobeRGB's white and vice versa.
Likewise sRGB is also not fully contained in ProPhoto (have you plotted the 2 sRGB profiles I've posted above?)
A sheet of white paper looks different under tungsten and under daylight...
... unless your eyes adopt to the different lighting conditions.
After adaption to the different lighting conditions the white paper will look "the same".

[Iliah]

Yay! We have a winner.

Again, not to put words in joofa's mouth, but I don't think he ever said, "I don't care about adaptation."  I think he was pointing out the case where you don't use it, as in his #1 of 4 cases.  Later, others put forth the idea that using adaptation is not always the 'right' way to do things, though the examples have been vague.

At least that's how I've understood this discussion.

You can say that - or you can say that we have no RGB space currently in common use that covers the whole gamut of visual response and does not include imaginary colours. While we need something here - for those HDR displays that are coming.

[Iliah]

Is 2 really greater than 1?

Border guards are useful but need close attention when put into operations. Do not allow them to act on their own.

[digitaldog]

I think he was pointing out the case where you don't use it, as in his #1 of 4 cases.

So when using these ICC profiles in any current application, when and how (and why) would a conversion take place without adaptation?

[MarkM]

You can say that - or you can say that we have no RGB space currently in common use that covers the whole gamut of visual response and does not include imaginary colours.

And you never will. It is a fundamental limitation of trichromatic reproduction. You cannot match all visible colors with only three real primaries.

[jeremypayne]

Border guards are useful but need close attention when put into operations. Do not allow them to act on their own.

You don't seem interested in actually contributing.  You seem to be intentionally vague and cryptic without offering clear and reasoned arguments.

How dissapointing ... I had thought you were more interested in teaching and spreading the good word.

Perhaps you've spent too much time arguing with the trolls at DPR ... Dunno.

[tho_mas]

And you never will. It is a fundamental limitation of trichromatic reproduction. You cannot match all visible colors with only three real primaries.

this is only a fundemental limitation of matrix profiles

[MarkM]

this is only a fundemental limitation of matrix profiles

It's more fundamental than that. You may be able to make a profile that can do crazy things and specify off the wall coordinates in LUTs, but you won't be able to actually reproduce the colors with only three primaries.

[Iliah]

You don't seem interested in actually contributing.  You seem to be intentionally vague and cryptic without offering clear and reasoned arguments.

How dissapointing ... I had thought you were more interested in teaching and spreading the good word.

Perhaps you've spent too much time arguing with the trolls at DPR ... Dunno.

My response was to Joofa.

I'm not interested in teaching at all and never was. What interests me is to help; mostly - to help people and ideas under attack from those who are only fit to play the leading role George Ruggle's piece.

[Iliah]

And you never will. It is a fundamental limitation of trichromatic reproduction. You cannot match all visible colors with only three real primaries.

Do you know why is it so?

[MarkM]

Do you know why is it so?

Yes. It's because the response curves of the cones overlap. You can't individually stimulate retinal cones separately. You always get unwanted stimulations which will lower the saturation of some colors you are trying to reproduce.

Hold on, let me find it…