You're not supposed to get significant data under 95. If you do, I think
your scans were badly done.
From the cineon web site:
http://www.cineon.com/conv_10to8bit.php
"For a normally exposed Cineon Digital Negative, a 90% white card will
be recorded at a code value of 685. The Dmin of the film is set to 95,
representing the blackest black that can be recorded (approximately a 1%
black card). In converting from 10 bits to 8 bits, the range of code
values from 95 to 685 are mapped to an output range of 0 to 255. In
between these end points, it is necessary to implement the gamma
correction that is described herein. "
and
"4.2 Reference Black
The default value for reference black is 95, which is the code value for
Dmin in the calibration of the Cineon scanner. If the negative is
over-exposed, the true reference black in the scene may fall at a code
value higher than 95. If so, this higher code value should be used. "
and
"5.2 Clamp black to 0
Output code values below RefBlack are clamped to a code value of 0 (no
negative code values are permitted).
The default value for RefBlack is 95. "
So, the scanner operator is supposed to callibrate the scanner so that
black on film is at 95 code value. When going to print, all the values
under 95 are lost anyway, film printers cannot print negative values.
On 21/04/2011 12:17, Hugo Léveillé wrote:
DPX scan with very dark value (below 95) goes under 0 once in linear.
What technique do you use in those cases ?
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