Re: Usable Tones in Different Gammas
Re: Usable Tones in Different Gammas
- Subject: Re: Usable Tones in Different Gammas
- From: Rolf Gierling <email@hidden>
- Date: Thu, 14 Dec 2000 02:24:29 +0100
Don Hutcheson wrote:
>
It is dangerous and incorrect to use Delta-E 1.0 as a definition of the
>
finest necessary tonal resolution.
As far as I know delta E 1.0 is the finest necessary resolution a human
eye
can recognize. The fact that the Lab colormodel is not as perceptual as
they
expected in 1976, they redefined the way to calculate delta E by using
CIE94
or CMC. So a change of 1 in Lab is not necessarily a change of delta E =
1.
>
Most displays will show between 200 and 256 discrete levels at normal
gamma
>
settings of 1.8 to 2.2.
May I redifine my suggestion of the discussion: How many different tones
that a
display shows up can the human eye detect.
>
For the record, perfectionists in the pre-press industry have known for
>
years that 256 levels are not enough to simulate true continuous
tonality,
this is what I said, there where graphics cards of Radius for example
that
worked with a 10 or 12 Bit LUT.
>
use 16-bit per channel devices, files and
software.
Is somebody listening: ATI, Matrox, Elsa (yes they had one long time
ago)...
Rolf Gierling
(Nobody is perfect)