A single fixed Output Transform vs a choose-your-own approach

[ChrisBrejon (Christophe Brejon)]

Hello,

happy to answer a couple of these questions to the best of my abilities.

@priikone

I think this has been well established as a fact of life, but I don’t think it has been established what are the reasons why this happens so often (anyone know?).

If I understood, the main reason why is “studio requirements”. Aka a project has to be ACES compliant, but will not use the ACES Output Transform. It has been brought up by Daniele and Josh Pines in meeting#5 (at minute 35:43).

@priikone

Is there a danger that post facilities, and software vendors, start providing their own rendering transforms, and suddenly there’s 15 slightly different versions of effectively the same thing? What’s the point of ACES at that point?

The point of ACES is to provide a Vanilla Transform (like it has always been the case) that can be used out-of-the-box. But if an expert user needs to swap the Output Transform for any reason, he/she should be able to do it easily.

@priikone

How would this be presented to the end user? What new settings would be expected to be exposed to the end user (such as a colorist) in these types of models?

I don’t expect new settings to be honest. But I could completely wrong. The important thing is that ACES would still work out-of the-box.

@priikone

What is the benefit of custom rendering transforms for these end users? Right know with ACES we have simplicity and consistency. Doesn’t that go away with custom renderings?

I don’t think it will complicate things. ACES would still work out-of-the box for all users. But if someone needs flexibility for whatever reason, his/her life will be much simpler.

@priikone

Since everyone always mentions the ARRI K1S1 I’m going to as well. To me ARRI K1S1 is not a rendering transform from the point of view of ACES. It’s a look, an LMT.

Hum, I do think the ARRI K1S1 is a DRT. There is a comparison of several DRTs on the dropbox paper. You can see the main differences, strength and weaknesses of each system : ACES, RRI, RED, FilmLight… ACES does come with a look as well.

@priikone

What’s the role of LMTs with different rendering transforms? Does it then mean that, in practice, LMTs would be tied to a specific rendering transform? If you change the rendering the look will also change. Could the LMT even break under a different rendering?

That’s a possibility. I have posted some images comparing ACES 1.2 to RED IPP2 in this thread. If you look at the saturated render of Louise, you will some gamut clipping with the ACES Output Transform.

To me, the beauty of this idea is that it is not mutually exclusive with the Vanilla ACES Output Transform (expression used by Thomas in meeting#2 at 35:09). So it is a win-win in my opinion both for non-expert users (such as myself) and expert users such as Daniele or Joshua.

Happy to discuss,
Chris