[Tig] When to use 444RGB or 444YUV for Dual link monitoring in a DI

adrian hauser ahauser at bigair.com.au
Sun Aug 5 01:14:52 BST 2007

Thanks Bob,
I have that exact book hear at my sunday morning breakfast table
and it does not actually define an amount of difference in saturation.
I'll keep reading in case I skipped over it. In some ways its more
interesting than the weekend news....

In attempting
to mimic the difference myself, if I view my rendered RGB files
in a YUV legal 'video range' monitoring environment and attempt to grade
to look similar I essentially increase contrast which by default increases
by about 15%. Does this make sense? When monitoring RGB I am essentially
setting my
blacks to 64 anyway as levels below that are not visible on the CRT.

This brings up another question...
# Assuming RGB is full range and
most color bars are set to "video levels" what does one use to correctly
set up saturation on a A grade CRT monitor fed with Dual Link RGB
or Full Range YUV. For Levels I have made a grey step wedge that I can setup
to correctly view and monitor levels above and below 64 and 960. Saturation
is a different story though.

Adrian Hauser.

----- Original Message ----- 
From: "Bob Friesenhahn" <bfriesen at simple.dallas.tx.us>
To: "adrian hauser" <ahauser at bigair.com.au>
Cc: "tig tig" <tig at colorist.org>
Sent: Sunday, August 05, 2007 9:51 AM
Subject: Re: [Tig] When to use 444RGB or 444YUV for Dual link monitoring in
a DI

> On Sun, 5 Aug 2007, adrian hauser wrote:
>> Thanks Bob,
>> How much 'color' would you say is lost?
> That is a very good question.  I know that it is answered somewhere in
> Charles Poynton's tome "Digital Video And HDTV" but I can't put my finger
> on it at the moment.  Perhaps it is answered in one of Charles Poynton's
> papers at http://www.poynton.com/Poynton-color.html.
>> Could this be defined as a loss of saturation as well.
>> Some of my tests using the RGB Linear output method
>> have given me a print with excelent reproduction of levels
>> but over saturated to the tune of about 20%!.
> Depending on how the RGB is defined, it could certainly be more saturated
> than what Rec.709 is supposed to support.  If the results are more
> saturated than what you are seeing on a calibrated display, then there
> must be a flaw in the output translation.
> Bob
> ======================================
> Bob Friesenhahn
> bfriesen at simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
> GraphicsMagick Maintainer,    http://www.GraphicsMagick.org/

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