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Let me preface this by saying I posted a question concerning why the increased lumens with the use of the BC feature. f300v10 was kind enough to point me to a DLP white paper concerning this. I know some here believe brilliant color is a gimmick, unrealistic and causes noise. I disagree. With more light comes more flaws, perfect lighting is necessary for models to look their best. A friend is a Marantz dealer. Years ago after watching dozens of movies in his store on a 12s2 he invited me in for the same clips. Something was very different. He revealed the 10s1. The color in the starfield was remarkable. Here 4 years later I'm starting to experience the same effect. I've seen these same clips a thousand times with every FP imaginable. I Cal'd my W5000 for grayscale and lumen output equaled between BC on or off. With it on I achieved a level a level of separation, an embossed pop, that greatly exceeded what it was with it off (demo clips: first 10-15 min of Hellboy,Fifth Element BR's,Hulk HDDVD) Again, light levels were matched. Reminiscent of the 10s1 experience. It got me thinking, outside the box, pun intended, because even the HD gamut is only part of what's visible. And I'll admit again, BC looks different when the norm has been without it. Right or wrong it looks different. It takes getting use to, the norm is a safe zone, I'm use to it, its easy. With BC my ftLs increased from 10 to 15, a 50% increase as advertised and the color is most definitely more vibrant, more real I think, even in dark scene's. So my questions are, Does 1-chip+BC = 3-chip, at least in theory. Is the CIE triangle still relevant, or, do we need to move pass this? The norm is 3 and 3, primary/secondary, but is it time to look past this to a truly expanded gamut with 6 primaries and a polygon shaped gamut? Is this and Deep Color the next step up the ladder? Dave
 

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I think a purist would or could (should?) argue that there is only one correct or accurate gamut that present HD consumer video should be rendered at and that is Rec.709.


I think a purist would relish an expanded gamut but only with source material that correctly and accurately targets the expanded gamut.


There doesn’t seem to be much consumer source material to accurately take advantage of xvYCC, DCI or other expanded gamuts or the deeper color depths to smoothly address inside an expanded gamut.


Dave
 

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Quote:
Originally Posted by coolrda /forum/post/14299100


So my questions are, Does 1-chip+BC = 3-chip, at least in theory.

No.

Quote:
Originally Posted by coolrda /forum/post/14299100


Is the CIE triangle still relevant, or, do we need to move pass this? The norm is 3 and 3, primary/secondary, but is it time to look past this to a truly expanded gamut with 6 primaries and a polygon shaped gamut? Is this and Deep Color the next step up the ladder? Dave

The CIE triangle will be relevant as long as that's what th film makers are using for making the film. Using a different gamut than the film maker (whether that be SMPTE-C or REC.709) will _never_ make the picture more "natural" or whatever you like to call it. It's not your PJ's technology or quality that limits the accuracy of your colors, but the film-makers monitor. Whatever you do, you cannot increase the colors beyond what the film-maker put into the film, without introducing errors in the colors. It may look subjectively "better" to you, as it does to a lot of people, but it is definately NOT more "real". There is no way to take advantage of new display's capabilities to increase the color gamut, if the source material doesn't include it.


That said, it would certainly be possible to get better pictures than with REC.709, if both the source material and the displays were to operate with a greater gamut. However, due to backwards compatibility issues, it's not likely that we will see that any time soon.
 

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I have been intrigued by the CIE triangle for some time, as well. Has anybody ever obtained an overlay comparison of various triangles, just to see where they lay? If you compare what gamut extremes are covered by 709, rgb, ntsc, and film, you may be in for a shock.
It seems to me that the area defined by 709 was not particularly to challenge any color extremes, rather to conservatively carve out an area that 8-bit color could adequately cover w/o getting into banding issues.


From that respect, reaching out to even greater extremes will definitely require higher bit depths. The polygon color system is also an interesting idea to open up available gamut with just the classic 8-bit depths (Though, it is still technically the addition of 3 more color channels, each with their own 8-bit depth. So, the gross data load will still be considerable- comparable to an rgb/16 bit in bandwidth terms).
 

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Quote:
Originally Posted by coolrda /forum/post/14299100


Does 1-chip+BC = 3-chip, at least in theory

No.


When talking of expanded gamuts and their usefulness, the source coding needs to be considered. If the source material does not comply with the display gamut, all your colors will be wrong.


ATM if you want an expanded gamut with corresponding source material you need to look at a DCI install. The color difference with a DCI compliant system is significant. DCI installs are becoming far more common, and are one of the growth areas in the high end. Look at the high end forum and you'll notice a lot of movement to that type of system. Colossal data rates and special gamma curves also add to the overall capability.


Source material can be an issue, if you are not on the circuit. That will be addressed, and made available, fairly soon.
 

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Quote:
Originally Posted by Mr. Hanky /forum/post/14323425


It seems to me that the area defined by 709 was not particularly to challenge any color extremes, rather to conservatively carve out an area that 8-bit color could adequately cover w/o getting into banding issues.

Basically SMPTE-C, EBU and Rec.709 gamuts were defined by the available CRT's. Consumer standards needs to be backwards compatible, therefore you had to define a standard that you can reproduce adequately with an average CRT. That is why SMPTE-C primaries were "invented" in the first place, the first set of primaries defined in 1953 was way too ambitious, and the manufacturers simply couldn't design a CRT with such saturated primaries, that didn't have blooming issues.


For Digital Cinema we don't have the constraints of the CRT to think of, so we can use a much larger gamut.
 

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Quote:
Originally Posted by Otto J /forum/post/14330586


Basically SMPTE-C, EBU and Rec.709 gamuts were defined by the available CRT's.

Good point about the CRTs being the driving factor. From what I have been told from somebody who is a lifetime member of SMPTE and was around at the time, SMPTE-C was chosen mostly because Conrac was willing to share their formula for achieving their primaries, while other companies who had achieved more saturated primaries (or at least one primary, like red) considered the methods trade secrets that were valuable and were not willing to share them like Conrac was. This may go along with what you said, but with the clarification that "available CRTs" were those were the formulas could be shared with all manufacturers and didn't count those that couldn't/wouldn't be shared because of business reasons. I'm not sure how much the blooming issues played into this and how much the trade secret factor played into this though.


--Darin
 

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The original NTSC primaries were abandoned because the consumer manufacturers wanted to make their displays brighter.


I don't think blooming has anthing to do with it? (Though if you drive a CRT brighter than the electron beam would bloom/lose focus.)


2- SMPTE C / Conrac

I heard that SMPTE C adopted the Conrac primaries since most post houses were using Conrac monitors at the time.


The primaries themselves are no trade secret- anybody can measure them. The phosphor composition could be a trade secret... though I don't know if the standards document gives away their phosphor composition/formula. One could definitely check by looking at the standards document.


3- SMPTE doesn't make consumer standards.


4- I believe Rec. 709 was just a political compromise... the choice of EBU red and blue but a green halfway between EBU and SMPTE C is weird. Why not just run with the EBU primaries instead?


Now there are 3 different sets of primaries to deal with instead of 2. Though in practice, people just use one monitor (e.g. a sony bvm with SMPTE C phosphors) for everything.
 
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