Colour Space Options

[Richard M Knight]

What does the 'scene' suffix mean in colour space options?

[R Neil Haugen]

In video post terms, that would be a "scene referred" color space. In other words, and way probably over-simplified, as produced by the camera.

Using the Rec.709 option, "scene referred" would be using the camera transform specified in the Rec.709 specifications, but not the display transform. Ergo a roughly gamma 1.96 transform or "power law".

So I'm wondering if the purpose there would be to allow us to apply color correction to specifically set scene-referred clips. This is something most colorists now prefer.

The media is in either it's native "space" or transformed to a common wide space/gamut for the project. A display transform is used then on the signal sent to the display so you see the scene-referred final image, but your correction is applied to the original data sort of as-was.

Or it may be expected to be used for pass-through work going to a colorist.

@Fergus Hor @eric escobar would have the actual answer here.

And as always,  Remote, yea, it should be better documented.

[eric escobar]

Hello Richard,

"Scene", in this context, means scene referred image data, which is image data that closely represents the original scene, without limiting color or dynamic range.

Best,

Eric

[Remote Index]

@eric escobar 

While I find your explanation minimal at best, it is better than nothing.

Is there a reason Adobe is keeping this information a secret from its paying users?

R.

[eric escobar]

Remote Index, are you asking for more clarity on what scene referred image data is?
This isn't something created by Adobe, it's a common data type in imaging for the last twenty years. Are you wanting an explanation/ definition for each of the color spaces available in the "Override Media Color Space" pulldown menu?

I'm unclear on what your question is.
Eric

[Warren Heaton]

@Richard M Knight 

For color spaces that can be scene-referred or display-referred, the Override Media Color Space displays "(Scene)" appended to the name of the colors space to differenciate between the two.

[R Neil Haugen]

And to add to the information for users ... "scene referred" is a relatively new concept and practice for color correction/grading processes. And is normally defined as applying corrections to the media "as it came from the creating device" ... such as log footage or RAW footage ... while the media is still in that 'space', before it is converted to the "linear display space".

"Display referred" means applying corrections to the image after the image goes through the transform process to "linear display space".

Which is how "we" always used to work. Including pro colorists even, in Resolve. As I learned to work years ago. 

Most colorists these days prefer to work in scene-referred workflows, as the image data at that point is still "wide", not constrained/reduced to display space 'dimensions' ... and therefore more subtlety and finesse is possible.

So typically a colorist working in Resolve or Baselight will set a sequence color space that is very "wide" ... both in tonal range and color gamut, two very different things ... such as some form of Arri Wide, or "Davinci Wide Gamut". The program then does a transform (via algorithms, NOT LUTs ... !) to that selected space for all clips on that sequence.

The user also specifies the Display space, and the program does a transform of the image data after and luma/chroma changes, to that display space for viewing while working. Typically you would choose a display space the same as your expected delivery space. So pehaps an ArriWide sequence space, with a Rec.709 display space.

The color tools are mostly "color space aware" in Resolve, so they behave slightly to notably different depending on the working color space. In this example, the tools behave in their 'wide gamut' mode, and you see the actions of them after the transform to display space ... but again, that transform is after the corrections, which were applied to the wider gamut data.

In Premiere 25, we get the option to set wider gamut sequences, with algorithmic transforms of any clip to the working (sequence) wide space/gamut, and the option to set a separate display space, between Rec.709 and of course HLG or PQ for HDR workflows.

Much of Lumetri's color correction tools are also now "color space aware" ... and it's subtle, but they do work differently if you work in a wide gamut sequence compared to a narrow gamut, specifically Rec.709 working space.

It is also possible in 25.x to completely turn off all color management, which for some total pass-through workflows, is now needed.

I hope this helps some folks navigate the changes. Alexis Van Hurkman, head of Adobe pro video color, and his team including Eric above and a number of others, have done an incredible job so far to get a working wide-gamut base to Premiere.

I share a couple relatively minor concerns, with Shebbe and Hector Berrebi, who've posted on the threads on the public beta forums. But those are rather minor withal.

In general, this is a MASSIVE and very welcome huge leap forward. Thanks to all involved!