[Tig] Apple Color strange behavior

Dan Tatut 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

Dan

Dan Tatut
VP Business Strategy & Development
*MARQUISE TECHNOLOGIES SA*
Rue des Avouillons 4
1196 Gland - Switzerland
Tel +41 22 364 54 71
www.marquise-tech.com <http://www.marquise-tech.com/>  

*IBC Hall 13, Booth 13.A30*

Joe Owens wrote:
> Sohonet http://www.sohonet.co.uk sponsors the TIG.
> Digital Vision supports the TIG.
> ====
>
>>
>> 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
>
>
>
> _______________________________________________
> http://reels.colorist.org
> http://tig.colorist.org/wiki3




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