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Discussion Starter · #1 ·
Everything is based around the D65 standard, which is fine and great for movies, but what if one prefers a slightly cooler color (say, 8300K) for a slightly "whiter whites" look for regular TV viewing or sports?


I own a Pioneer 600M and Eye One LT and hope to calibrate at least one input to the correct D65 standard for movies, but is there a way to use ColorHCFR to adjust grayscale to a different color?


I know this sounds like blasphemy in this forum, and a number of you are probably asking what the point is. I could just eyeball it "until it looks good", but I'd like to know I'm getting my RGB settings to "white" for maximum contrast and dynamic range, even if that color of "white" isn't the warm white of D65.


Anyone ever do this?
 

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D65 is the correct standard for rec.709, wich is the defining color space for HDTV in America.


If you chose to deviate from the standard you can do so, but there are no guidelines, because it is no longer accurate to any standard.


Calibrating for maximum contrast?

Where do you draw the line when you deviate from standards?

Do you say aslong as it's +- 1000K, 2000K?

What about when your white point moves completely off the CCT line (the line that defines white at a color temprature, because every color has a temprature)?


The fact of the matter is if you are creating your own standard to calibrate to, it really doesn't matter at all, you could for instance say that it is correct to have a color temp of 6500K at 30% and 8500K at 80% and no one can argue with you.


The fact of the matter is your picture will be the most accurate, look most like what the camera guy saw when you calibrate to D65 and rec.709


Also D65 shouldn't be considered "warm" it should be considered neutral, it exists almost at exactly the dead center of the CIE gamut. Warm is 5400K.
 

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Greetings


I want 2+2 = 42 ... rather than "4" ... um ...okay. It's your TV ... do whatever you want with it?


Once you deviate from standards ... you pursue wrong answers ... which is your right. Lots of wrong answers out there ...


Regards
 

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Quote:
Everything is based around the D65 standard, which is fine and great for movies, but what if one prefers a slightly cooler color (say, 8300K) for a slightly "whiter whites" look for regular TV viewing or sports?

Also, D65 is the standard for television as well. So sure, you can do whatever you want, but you are pursuing arbitrary images and you no longer care about image quality. That's fine, but it's obviously not calibration and it's a goal that explicitly eschews quality images.
 

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Discussion Starter · #7 ·

Quote:
Originally Posted by sotti /forum/post/17027119

http://en.wikipedia.org/wiki/File:planckian-locus.png



For reference, D65 is white.

It's one white. The white of a black body radiator at 6500K.

Quote:
Originally Posted by sotti /forum/post/17027119


...If you chose to deviate from the standard you can do so, but there are no guidelines, because it is no longer accurate to any standard.

D75? This is a standard, no? You're saying that using the rec.709 color palette in conjunction with another color standard would mess up the color mapping? I see.

Quote:
Originally Posted by Michael TLV /forum/post/17027238


Greetings


I want 2+2 = 42 ... rather than "4" ... um ...okay. It's your TV ... do whatever you want with it?


Once you deviate from standards ... you pursue wrong answers ... which is your right. Lots of wrong answers out there ...


Regards

Lol, I knew I'd get someone with this one. A little more attitude next time please.
 

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Quote:
Originally Posted by Chris Campbell /forum/post/17027519


It's one white. The white of a black body radiator at 6500K.

It isn't actually, D65 is distinct from the point on the planckian locus at 6500K, as noted in the image previously posted. D65 is on the Daylight locus, on the planckian locus. The CCT of D65 isn't exactly 6500K anymore either.

Quote:
D75? This is a standard, no? You're saying that using the rec.709 color palette in conjunction with another color standard would mess up the color mapping? I see.

Of course it messes up all the colors! There are different D standards for different industries and applications. Print industry often uses D50, etc, it depends.


But video is fundamentally a reproduction chain, and the goal for good images is to match exactly or as closely as possible the original image, and to do that you have to match the standard, and that's D65.

Quote:
Lol, I knew I'd get someone with this one. A little more attitude next time please.

It isn't attitude, it's truth. The standard is what it is, and in order to match the original image, you have to match the standard. If you don't, then you are creating your own image with no relationship to any referent, and the goal has now changed from reproduction to an arbitrary new production that has no relationship to the original image, and hence no meaningful evaluation in terms of image quality. You're throwing quality out the window when you do this, which is fine, it's a free country, but you just have to understand this basic fact.


If you care about image quality, you necessarily must concern yourself with image accuracy. If you don't care about accuracy, then you don't care about quality.
 

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Quote:
Originally Posted by Chris Campbell /forum/post/17026878


Everything is based around the D65 standard, which is fine and great for movies, but what if one prefers a slightly cooler color (say, 8300K) for a slightly "whiter whites" look for regular TV viewing or sports?


I own a Pioneer 600M and Eye One LT and hope to calibrate at least one input to the correct D65 standard for movies, but is there a way to use ColorHCFR to adjust grayscale to a different color?


I know this sounds like blasphemy in this forum, and a number of you are probably asking what the point is. I could just eyeball it "until it looks good", but I'd like to know I'm getting my RGB settings to "white" for maximum contrast and dynamic range, even if that color of "white" isn't the warm white of D65.


Anyone ever do this?
http://www.avsforum.com/avs-vb/showthread.php?t=1021933

Do you request that your color photos be printed on blue paper? Do you attend live sporting events wearing blue tinted glasses? Are you Japanese? They use a much higher white point for their broadcast standard. The rest of the world uses D65 for video white. The ISO standard for monitor white point in digital graphics and photography is D50. Comparing Michael's comments to yours leads me to conclude that you are the one with the peculiar "attitude."
 

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Quote:
Originally Posted by Chris Campbell /forum/post/17026878


Everything is based around the D65 standard, which is fine and great for movies, but what if one prefers a slightly cooler color (say, 8300K) for a slightly "whiter whites" look for regular TV viewing or sports?


I own a Pioneer 600M and Eye One LT and hope to calibrate at least one input to the correct D65 standard for movies, but is there a way to use ColorHCFR to adjust grayscale to a different color?


I know this sounds like blasphemy in this forum, and a number of you are probably asking what the point is. I could just eyeball it "until it looks good", but I'd like to know I'm getting my RGB settings to "white" for maximum contrast and dynamic range, even if that color of "white" isn't the warm white of D65.


Anyone ever do this?


Chris when you calibrate to your new standard, just keep blue high...



if 30% window has


red = 100%

Green = 100%

Blue = 110%



Keep 80% window at the same settings


red = 100%

Green = 100%

Blue = 110%


The higher the blue number the higher the color temp!


ColorHCFR will tell you where you are, once you finish a greyscale run through.
 

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Quote:
Originally Posted by Michael TLV /forum/post/17027238


Greetings


I want 2+2 = 42 ... rather than "4" ... um ...okay. It's your TV ... do whatever you want with it?


Once you deviate from standards ... you pursue wrong answers ... which is your right. Lots of wrong answers out there ...


Regards

But what if my answer is 4.12?


Am I still wrong?




Because it is very hard/impossible to hit perfect D65 at every video level.
 

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D65 is already a slightly blueish whiteit's just that we're so used to the defaults being much higher than that, it looks reddish at first.


I'd give it some timeonce you've watched enough D65 content, higher colour temperatures will start to look worse, rather than better.
 

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Quote:
Originally Posted by SOWK /forum/post/17028330


But what if my answer is 4.12?


Am I still wrong?




Because it is very hard/impossible to hit perfect D65 at every video level.

D65 is the target standard white point for video. There is no perfect video display. The objective in video calibration is to come as close to the standard as a given display device allows. But you knew all that already, didn't you?
 

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Quote:
Originally Posted by Chris Campbell /forum/post/17026878


I know this sounds like blasphemy in this forum, and a number of you are probably asking what the point is. I could just eyeball it "until it looks good", but I'd like to know I'm getting my RGB settings to "white" for maximum contrast and dynamic range, even if that color of "white" isn't the warm white of D65.

I think your question has sparked the response it has because it is hard to make out what you are asking because the question seems to contain some implied assumptions that aren't correct.


First, the color temp you mention, would NOT set "RGB settings to 'white'". It would set your RGB settings to something that is distinctively blue, as shown below.




"White" is the absence of color by definition.


Second, your stated goal is getting "maximum contrast and dynamic range", but that goal is unrelated to making your white point excessively blue. You achieve this goal by correctly setting your gamma and white and black levels.


Third, you seem to believe that D65 is "Warm." D65 is the correct white point because of the gamut of colors used in mastering broadcast, DVD, and Blu-ray content. In N. America and Europe the gamuts used are such that D65 is the correct white point--that is, the neutral absence of any color. For different gamuts, it would be a different point. In fact, DCI--which is not used for consumer sources--has a white point that is relatively green compared to D65.


Lastly, there have been some studies that suggest that many people mistakenly perceive a bluish white as "more" white. This is precisely the bias that people concerned with image fidelity have tried to fight through education and calibration to correct standards.
 

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Quote:
Originally Posted by GeorgeAB /forum/post/17028478


D65 is the target standard white point for video. There is no perfect video display. The objective in video calibration is to come as close to the standard as a given display device allows. But you knew all that already, didn't you?

Maybe...
 

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Quote:
Originally Posted by TomHuffman /forum/post/17028554



First, the color temp you mention, would NOT set "RGB settings to 'white'". It would set your RGB settings to something that is distinctively blue, as shown below.


You just had to one up me didn't you Tom...



You added the visual to improve upon my post #10.
 

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Quote:
Originally Posted by TomHuffman /forum/post/17028554


Second, your stated goal is getting "maximum contrast and dynamic range", but that goal is unrelated to making your white point excessively blue. You achieve this goal by correctly setting your gamma and white and black levels.

It depends on the kind of display, but if the display is naturally blue compared to D65 then increasing blue beyond D65 instead of turning it down to get to D65 would increase the dynamic range (when used to mean contrast ratio) unless the display is the type where when you turn blue down it turns it down for video black also.


A UHP lamp projector is the type where turning the blue and green down to reach D65 reduces on/off CR. Using a filter to reduce them to match D65 doesn't.


If he meant "contrast" as in ANSI lumens then those can be increased by going to a higher color temperature with many displays also.


I'm not saying he should do it, but one thing going to D65 often means is getting less than maximum contrast ratio.


--Darin
 

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Discussion Starter · #20 ·

Quote:
Originally Posted by SOWK /forum/post/17028304


Chris when you calibrate to your new standard, just keep blue high...



if 30% window has


red = 100%

Green = 100%

Blue = 110%



Keep 80% window at the same settings


red = 100%

Green = 100%

Blue = 110%


The higher the blue number the higher the color temp!


ColorHCFR will tell you where you are, once you finish a greyscale run through.

Thanks, I'll give that a try.
 
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