ACES doesn’t do any magic. It exacerbates problems across the board. In no particular order:
- It uses wide primaries that are close to BT.2020 with an imaginary green component. This leads to negative values, and because of the lack of gamut mapping, will break all imagery by default. This is easy to see.
- ACES for the sRGB output misplaces middle grey to a value that ends up approximately 0.8 EV lower than that of an sRGB-like display.
- LEGO, as cited, was passed off to a professional colourist who had to fix quite a few gamut mapping issues I believe. It was a different transform as well.
- ACES default RRT is vastly too contrasty to a disproportionate number of people. The nature of the aesthetic transfer function, coupled with this exaggerated contrast, exacerbates the default woeful looking results due to the lack of gamut mapping.
- ACES and Filmic share precisely the same dynamic range for sRGB display output. 16.5 stops, -10 EV to +6.5 EV. This can be confirmed by examining the ACES shaper for the sRGB output. This was by design.
There are plenty of demos out there on Twitter when this came up last time.
So where can ACES benefit you? In theory if you want to render to a wider gamut destination, the primaries of the rendering space are wide enough, but the lack of gamut mapping generates plenty of horrific looking issues and outright broken looking imagery.
Why is it adopted in pipelines? Post houses deal with a lack of colour knowledge on a day to day basis. ACES at least asserts a baseline. Very few places will be using the RRT as it is, and they all will have a professional colourist at the very least standing by to try and fix the issues, or at worst a colour scientist.
Finally, Blender is not colour managed. Had it been, Filmic would have been wide gamut using BT.2020 primaries.
Until Blender is fully colour managed, it simply isn’t ready to make the leap to wide gamut working spaces. The audience is barely ready as a whole, and the developers won’t have a care in the world until that pressure develops.
Will ACES help you generate “better” looking imagery by default? Flatly false. I’ll leave it to the folks who have done their homework to point out how clearly busted up the default output is, or one can search on Twitter for apples to apples comparisons, done by folks who know what they are doing.
False. It was rendered using DCI-P3 primaries.
Am I biased? I can happily bash Filmic on the technical issues. I can point out the warts on the Filmic colourspace and transforms easily. Will Filmic by default generate a better looking image? Do those tests. 