[Tig] Apple Color strange behavior
dtatut at marquise-tech.com
Thu Aug 12 18:27:28 BST 2010
indeed, it could be the problem.
Also check your TIFF tags... you may have something there as well and
you Apple Color interprets them
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Joe Owens wrote:
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>> Instead, I see a curve that appears to have a gamma of 1.22.
>> However, when I render it out of Apple Color without any grading, the
>> line is linear again (see figure below)!
>> Can anyone explain why Apple Color is adjusting the gamma on input?
> Here's some really interesting math:
> Rec 709 is supposed to be somewhere around gamma 2.2, but for purposes
> of argument, its what Apple COLOR is aiming for.
> Apple Quicktime (up to Snow Leopard) regarded all video as "linear"
> with a gamma factor of 1.8.
> Divide 2.2 by 1.8 and it comes out to: 1.22222222222 ...
> coincidence? Its driving every COLOR operator attempting to judge
> images on their Cinema Displays (or other VGA monitor) crazy.
> This might not be the exhaustive underlying reason (because COLOR has
> more than one strange behavior), but Occam says its a good candidate.
> Do not expect Apple to comment. The users of this application are
> your first, last, and only line of defense.
> Joe Owens
> Presto!Digital Colourgrade
> 302-9664 106 Avenue
> Edmonton, Alberta T5H0N4
> +1 780 421-9980
> jpo at prestodigital.ca
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