Super Saturated/Contrasted LUTs with D WG|Intermediate

Hello,

I am sorry for the topic as I am sure it is my mistake but it's been days that I search the internet and I cannot find a solution, probably something isn't clear for me about how to set proper color management.

If my understanding is correct we have two options when dealing with camera footage shot in LOG (specifically I am using Sony Alpha footage).

Option A
We declare an Input Color Space for the selected footage (right click on the clip --> Input Color Space), selecting the proper camera input color space (in my case S-Gamut3.Cine/S-Log3) and this, as we are in a color managed environment, transform the colors in REC709 space correctly into the Timeline Color Space (as set in the Project Setting).

Option B (which works also in non color managed environment)
Without declaring an Input Color Space for the selected footage (right click on the clip --> Input Color Space), leaving it as "Same as timeline", we add a Color Space Transform Node at the beginning of the node tree and, in my case with the Sony Alpha, I select:

- Input Color Space: Camera Input Color Space (in my case Sony-SGamut3.Cine)
- Input Gamma: Camera Input Color Space Gamma (in my case Sony S-Log3)
- Output Color Space: (what we set as timeline color space in the project setting panel)
- Output Gamma: (what we set as gamma for the timeline in the project setting panel

Now, apart from the fact that these two approaches lead to slightly different result but should be the same (slightly less saturated colors with Option B) there are a couple of things that are driving me mad if I set DaVinci Wide Gamut as timeline color space (leaving input color space - we don't care - and output color space set to REC709 Gamma 2.4).

Question 1
First of all I don't understand why, either that I use Option A or B to interpret correctly the footage in the first place, if I add a node with a Color Space Transfor set as:

- Input Color Space: Same as Timeline (which is DaVinci Wide Gamut)
- Input Gamma: Same as Timeline (which is DaVinci Intermediate)
- Output Color Space: REC709
- Output Gamma: Cineon Film Log

I get a completely different image than if I was working with the timeline set in REC709 Gamma 2.4.
I get much lighter colors, more contrasty and saturated which, obviouly lead to a wrong application of the film LUT (let's say Kodak 2383 D55).

Question 2
If I set the Timeline color space to REC709 Gamma 2.4 these two CST nodes lead to the same exact result:
CST 1:

- Input Color Space: Same as Timeline
- Input Gamma: Same as Timeline
- Output Color Space: REC709
- Output Gamma: Gamma 2.4

CST 2:

- Input Color Space: REC709
- Input Gamma: Gamma 2.4
- Output Color Space: REC709
- Output Gamma: Gamma 2.4

Instead if I set the Timeline color space to DaVinci Wide Gamut \ WG Intermediate these two CST nodes lead to completely different results:
CST 1:

- Input Color Space: Same as Timeline
- Input Gamma: Same as Timeline
- Output Color Space: REC709
- Output Gamma: Gamma 2.4

CST 2:

- Input Color Space: DaVinci Wide Gamut
- Input Gamma: DaVinci Intermediate
- Output Color Space: REC709
- Output Gamma: Gamma 2.4

The second being much much darker and saturated. ...why???

I am sorry for the long message but this thing is driving me crazy.
I would love to use DaVinci Wide Gamut for color correcting, obviously, but for now I cannot make it work...

Thank you very much!


Ale