Hue vs. Sat. Vs. Saturation control

[Thomas Singh]

Do you know what is the difference between the Hue vs. Sat when it comes to global saturation changes?
I would believe that lowering the whole line in Hue vs. Sat would be the same as lowering the global saturation but it seems to behave a complete different way. Any idea how this works?

[Marc Wielage]

Hue vs. Sat generally works on a pin-pointed shade of color. You can dial the entire line up and down, and as far as I know that's the same as an overall saturation change. 

[Thomas Singh]

It behaves totally different when you drag the line down, try for yourself. 

[Marc Wielage]

It probably would be easy to check with bars and a scope -- try both methods and see what happens. Color Boost also provides a different way to desaturate, affecting the most-saturated or least-saturated parts of the signal (depending on how you use it). Having different methods helps, but I have to confess, I'm so under the gun most of the time, I grab whatever I think will get there fastest and try that first. Keys also provide a way to selectively desat just part of the signal (even a large part, if you widen it out), but you have to be very careful about qualification and making it as soft and artifact-free as possible.  

[Orash Rahnema]

22 hours ago, Thomas Singh said:

It behaves totally different when you drag the line down, try for yourself. 

Can it be that hue vs Sat works on HSL or some different colour space rhater then the rgb colour space that Sat use.

I belive Sat control works in RGB using 709 primaries, not sure about curves, the same nature of them makes me believe they are in hsl.

But then again i might be wrong

would be interesting to check

Edited January 12, 2020 by Orash Rahnema