[Tig] (was Oxberry) scanners

[Nichols Craig]

How about just using 16 bits in A/D stage and keeping data 16 bits until
you need to output it?  

This is currently being done in some scanners.

Disclaimer, I work for Thomson Grass Valley. Opinions expressed are my
own.

Craig

Craig Nichols
Sr. Tech. Support Engineer / Film
Thomson GVG
2255 N. Ontario St. Suite 150 
Burbank, CA 91504 
818-729-7720 (office) 
818-729-7750 (fax) 
800-547-8949 (24 hour hotline) 
Craig.Nichols at thomson.net
Checkout FAQ page here
http://gvg.custhelp.com/cgi-bin/gvg.cfg/php/enduser/std_alp.php

-----Original Message-----
From: tig-bounces at tig.colorist.org [mailto:tig-bounces at tig.colorist.org]
On Behalf Of Micheletti, Bob (NBC Universal)
Sent: Thursday, November 30, 2006 9:53 AM
To: Jason Crump; cws at al.com.au
Cc: tig at colorist.org
Subject: RE: [Tig] (was Oxberry) scanners

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> All i basically wanted from the scanner is... if i have a 
> given density, i
> want the sensor to give the correct cineon CV straight out of the A->D
> conversion without any down-stream CV->CV luts. 
> best,
> jason
> colorist
> mumbai

As I understand it, the common practice among scanner manufactures is to

A>D at 14 (or more?) bits then LUT the CVs to get log
(14bit/lin>10bit/log LUT).
I think what you are describing is using a log preamp between the sensor
and 
A>D which theoretically would yield 14 bit (or more) log data.  This is
not a 
new idea but of course more complicated and less stable (more analog
circuitry).
Come on scanner engineers...anyone doing it this way?

I defiantly side with the group that wants as much range as possible in
the 
scanning stage and have found many times that base cal scans have
discarded 
unrecoverable information.  It does make the colorist and the engineers
work 
more, but in a "controlled environment" the end product will be much
better
if the entire CV range is used.  This of course is a bad idea for a
scanning 
service with many customers where standardization is most important.
Evan 
in that environment I believe it is better to rough grade the scans to a
middle
light and not just base cal.  Hopefully none of us believe the
information 
below cv 95 and above 685 can be discarded or rolled off.

One thing is for sure!  It is much easier to match back effects work
when the 
whole film is DI than it was when we had to match back only one shot in
a 
sequence to the O-neg.  If the information is discarded on the entire
film you 
don't miss it as much. ;-)

Bob Micheletti
Engineer
Universal Pictures

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