[Tig] Canon 4K monitor

David Corbitt dcorbitt77 at comcast.net
Tue Jan 28 14:15:10 GMT 2014


Original NTSC was very optimistic, very wide gamut compared to everything else until very recently, perhaps 40-50 years ahead of its time considering the available technology back in 1953. There were TV sets and monitors capable of reproducing that wide gamut but the brightness levels were considered way too low for the public so manufacturers fiddled with the Green and Red phosphors for more brightness and a much narrower color gamut and that’s where eventually SMPTE-C, EBU, and Rec 709 came from. The lack of standardization of display primaries during those unregulated market driven days was the cause of worldwide ridicule of NTSC (Never Twice the Same Color) as well as the analog encoding system prone to color phase errors. PAL/EBU fixed some of that but limited itself to a narrow gamut. I’m impressed with Rec 2020 for proposing a truly wide gamut (finally). I believe Samsung had a rear projection home display with 5 primaries using a DLP light engine that offered a large gamut according to a colleague of mine in the Los Angeles area (a well respected chief engineer and entrepreneur in high end post and 2D to 3D conversion). But it is no longer marketed. It used laser diodes for the 5 primaries.

I’m not saying NTSC primaries were widely adopted, just that the idea was good, implementation and regulation very poor.

Dave Corbitt

On Jan 27, 2014, at 12:23 PM, Stojmenovik, Goran <goran.stojmenovik at barco.com> wrote:

> David
> Our RHDM reference monitor was able to cover the DCI P3 gamut with RGB LEDs.
> The same statement goes for the Dolby monitor I believe.
> I am not doing LEDs anymore, so not aware of any recent progress.
> However, the LEDs by definition have a spread of wavelengths around the peak wl (even though it’s much narrower than phosphors or lamps), so I don’t expect that LEDs (or OLEDs for that matter) will be able to cover the Rec.2020 gamut, which defines spectrally pure colors (or just about).
> What is the reason you mention NTSC 1953 gamut? I thought this was never adopted on a large scale and was superseded by the SMPTE gamut which is much smaller (for SD, but not hugely dissimilar from Rec.709). Just a question…
> Best regards
> Goran
> From: David Corbitt [mailto:dcorbitt77 at comcast.net] 
> Sent: zondag 26 januari 2014 18:46
> To: tig at colorist.org Group; Stojmenovik, Goran
> Cc: Carl Skaff; Martin Parsons
> Subject: Re: [Tig] Canon 4K monitor
> Goran,
> What in your estimation is the largest gamut possible using existing or potential LED backlight technology?
> Here are the CIE 1931 parameters of Rec 2020, Rec 709, and the old original NTSC of 1953.
> (the chart may be blocked by the TIG’s rules)
> Color space
> White point
> Primary colors
>            RED                            GREEN                         BLUE      
> xW
> yW
> xR
> yR
> xG
> yG
> xB
> yB
> ITU-R BT.2020
> 0.3127
> 0.3290
> 0.708
> 0.292
> 0.170
> 0.797
> 0.131
> 0.046
> 1953 NTSC
> 0.310
> 0.316
> 0.670
> 0.330
> 0.210
> 0.710
> 0.140
> 0.080
> ITU-R BT.709
> 0.3127
> 0.329
> 0.64
> 0.33
> 0.30
> 0.60
> 0.15
> 0.06
> Dave Corbitt
> Whiting, NJ 08759
> http://tinyurl.com/lfezg3h
> On Jan 24, 2014, at 2:31 AM, Stojmenovik, Goran <goran.stojmenovik at barco.com> wrote:
> Carl Skaff wrote:
> " But not as big as 2020. From what I understand that is a silly big gamut."
> I agree: the only way to reach this gamut is with a laser projector with three very pure lasers. But due to many image quality issues (speckle etc.) and other considerations  this is not the way manufacturers will go. So for us Rec.2020 is unattainable in reality - unless they also specify attainable tolerances to go with the standard, which they have not.
> Carl, what is the size of this monitor? I missed that.
> Goran Stojmenovik
> Product Manager Laser Projection
> Barco
> This message is subject to the following terms and conditions: MAIL DISCLAIMER

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