Why nobody cares about colorspace gamut?

[Anton Meleshkevich]

I often hear and read here that nobody transforms LogC (or Red, or whatever) colorspace gamut to destination gamut. For example from AlexaWideGamut to Rec709 gamut. Everybody just makes a contrast curve, then some LGG, and that's all. Even If I go this way, I still use a gamut conversion LUT after normalization curves. Or I use gamut (colorspace) conversion plugin after the curves if I'm on Resolve.
Why do many colorists skip this step?

[Thomas Singh]

Because adding a normalization Lut (Log --> Lin) or using curves whatever to a Lin destination is the same thing. Some prefer using a Lut for this, others to do it manually. You can of course combine a Lut transform with e.g. curve adjustments if you like but there is no point in normalizing with curves first for then to do a Log to Lin conversion with a Lut because you're already there.

[Anton Meleshkevich]

I'm talking about gamut. Not gamma.
For example, here is gamut conversion from AlexaWideGamut to Rec709 gamut. It affects only colors.
LUTs, I'm talking about, contain just an RGB matrix in linear space.

Edited November 30, 2017 by Anton Meleshkevich

[Thomas Singh]

The camera manufacturer LUT's that's most often used to "normalize" the image also transfer chroma values and affect the gamut.

[Anton Meleshkevich]

Yes, I know it. And I talk about it since my first post in this thread.

My question is why do many colorists just ignore gamut. They just make RGB curve to normalize image. But ignore gamut correction.

[cameronrad]

I'm pretty sure most of the colorists that are truly familiar with 3DLUTs care about gamut. Maybe not the newer inexperienced colorists.that just know lut's for looks. Before the whole look LUT thing, they were for technical color space transforms. If those LUTs were just transforming curves, they wouldn't need to be 3DLUTs and could just be 1D LUTs/Curves. 

 

I think some of the good technical information has pushed in oblivion by clickbaity tutorial blog posts or people just putting out misinformation. I imagine the adoption of aces would bring more people's overall awareness back to colorspace transforms and gamut, gamma, etc.  

Edited December 2, 2017 by cameronrad