[Tig] 18% gray?

Sam Holtz SHOLTZ
Fri Dec 2 17:40:28 GMT 2005


--
Thanks to everyone for supporting the TIG through
the years.
--
Sorry for my typo's, the surrounding average viewing illumination should
read 6 fl. Not a fl. And I was VP. director of engineering for the Editel
group at that time.  


Sam Holtz
email: samh at ieee.org and sam at ste-ca.org
19174 Doral Place / Porter Ranch, CA 91326-1223
818-366-3659 / FAX 615-658-8742
"No race, country or individual has a monopoly of good or evil" 
Winston Spencer Churchill

-----Original Message-----
From: tig-bounces at tig.colorist.org [mailto:tig-bounces at tig.colorist.org] On
Behalf Of Sam Holtz
Sent: Friday, December 02, 2005 9:09 AM
To: 'Jim Mann'; 'Bob Friesenhahn'; 'Ronald Williams'
Cc: 'Telecine Interest Group'
Subject: RE: [Tig] 18% gray?

--
Thanks to everyone for supporting the TIG through the years.
--
Let me set the record straight. Aprox. 1974-1975 CONRAC CY-A and CY-B, all
vacuum tubes series (the Only standard of the Industry at the time) was been
replaced by RH-A series mostly transistorized, and eventually 6142 series
all solid state, except for the picture tube. Colorimetry, color space,
color temperature was different. Jack, Calloway, Vidtronics, a Technicolor
company and also wit TAV, Laurent Lau of Vidtronics, and myself, in the
video insert stage from Vidtronics, each of us set up the old monitors, to
the standard we had in Hollywood. Documented it, and made Conrac conformed
with that standard. We use 6500 degrees Kelvin for the white field (using a
Kelvin meter) we can Only achieve 60 fl. On the white flag. We determined
that a surrounding average viewing illumination should be 10% of the white
flag, a fl. reflected at 6500 degrees Kelvin and the color of the phosphors,
must match the old CRT's used, since that determines the color space. At
that time Conrac call this the HOLLYWOOD STANDARD, BARCO, that was starting
to get in into the US market, Panasonic and Sony had different parameters.
However Sony was the first to adhere to this HOLLYWOOD STANDARD, and the
following year SMPTE officially adopted this HOLLYWOOD STANDARD and called
it SMPTE, at that point all monitor manufactures followed SMPTE
recommendation. Note that this standard was created for HIGH QUALITY
PROFESSIONAL CRT MONITORS. Projection, would NOT QUALIFY or apply this
standards. But it should simulate or approximate standard film projection,
which is BLACK Surround NO ILLUMINATION and the color space such as it
matches standard film. We are getting closer to that but is not there yet.
DLP das NO Coloration added as LCD. However because of clever digital
manipulation of matrixes, colorimetry and color space is approximated.
As you can see It has NEVER being a 18$ gray anywhere 


Sam Holtz
email: samh at ieee.org and sam at ste-ca.org
19174 Doral Place / Porter Ranch, CA 91326-1223
818-366-3659 / FAX 615-658-8742
"No race, country or individual has a monopoly of good or evil" 
Winston Spencer Churchill

-----Original Message-----
From: tig-bounces at tig.colorist.org [mailto:tig-bounces at tig.colorist.org] On
Behalf Of Jim Mann
Sent: Thursday, December 01, 2005 3:56 PM
To: Bob Friesenhahn; Ronald Williams
Cc: Telecine Interest Group
Subject: RE: [Tig] 18% gray?

--
Thanks to everyone for supporting the TIG through the years.
--
Hi All,

18% gray is considered the reflectance value for flesh tone, blue sky and
green grass, (zone 5, I think) That coupled with a white chip and black chip
are the best friends of the colorist.

The Neutral back ground or backlight set up as Mr. Williams suggests is the
way to go. It can be 18% but by no means has to be.

Regards,
Jim

Jim Mann
Senior Colorist
Synchro Film and Video
http://www.digitalvision.se/customers/freelancers_mann.htm
http://tig.colorist.org/wiki2/index.php/User:Jim_Mann




participate in the tig wiki pages at http://tig.colorist.org/wiki
_______________________________________________
Tig mailing list
Tig at tig.colorist.org
http://tig.oktobor.com/mailman/listinfo/tig



participate in the tig wiki pages at http://tig.colorist.org/wiki
_______________________________________________
Tig mailing list
Tig at tig.colorist.org
http://tig.oktobor.com/mailman/listinfo/tig



participate in the tig wiki pages at http://tig.colorist.org/wiki
_______________________________________________
Tig mailing list
Tig at tig.colorist.org
http://tig.oktobor.com/mailman/listinfo/tig




More information about the Tig mailing list