[Tig] color vision - contrast affects saturation

[TSassoon at aol.com]

In a message dated 3/20/07 5:40:40 AM, jack-cml at focuspointfilms.co.uk writes:

> I've often wondered why tonal manipulations can affect colour saturation.
> 

Saturation results from differences between color channels. If all channels 
are the same, you have a shade of gray. At the other extreme, if one channel is 
full on, and the others off, then you have a primary color at full brightness 
and saturation. If one is full on, and the others half on, then you have a 
primary color at full brightness and half saturation.

When you, for instance compress levels, you're also increasing the contrast 
between channels, and thus increasing saturation.



Tim Sassoon
SFD vfx & creative post
Santa Monica, CA






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