ACES...

[Bill Anderson]

Yes, we might have to rename Jim, The Red Baron

[Brendan Bolles]

I find it very interesting to hear someone say that the ACES workflow makes their images look worse, because it seems to me that look really shouldn't enter into it. It should just be a workflow that can create any image that any other workflow could create. If there were technical limitations that could impact image quality, that would be one thing. But my understanding is that the bandwidth of 16-bit float should prevent that from being an issue. It'd be like saying TIFFs make your images look worse than PNG, or a Nikon NEF looks better than a DNG. They may have workflow advantages and disadvantages, but ultimately the same data is getting passed around.

Or maybe the problem is the RRT? If you don't like what it does to your images, then that could certainly be a problem. But you're not forced to use it are you?

I see IIF/ACES as just a modernization of the Cineon/DPX based workflows:

Cineon -> IIF (OpenEXR)
Log -> ACES (linear, with standard color primaries)
Film Look -> RRT


To me the main advantage is that instead of everyone passing around 10-bit log and a LUT, you bake it into a 16-bit float ACES file that everyone will read the same. Nothing should get lost in the translation, I should think. You could always convert the ACES back to log and work as you always have (and I'd expect many tools were doing just that).

But that's just me talking from a theoretical standpoint. Very interesting to hear real world use cases.


Brendan

[Gunleik Groven]

Brendan, I think the "should" is the important word here.
It's all in the in- and output transforms.

[Martin Stevens]

They say... garbage in, garbage out. And therefore, quality in, quality out,
but a bad LUT or transform can ruin quality material.

[Graeme Nattress]

The resulting look of an ACES rendered image is a combination of IDT (which we do, and is correct to spec) grading, RRT and ODT. If as in some of the R&D RRT+ODT combos the default "look" is too strong, it can look great with some shots and poor with others, as if it's heavily fine-tuned for one kind of image at the expense of others. It can also make grading to an "opposite" look rather hard. Can you imagine grading Girl With Dragon Tattoo look, if your view-LUT starting point gave you Pirates Of the Caribbean 4 as your starting point? Both excellent looks by excellent colourists, but both very very different....

Graeme

[Tom Hamilton]

Horses for courses Graeme. Many of us depend on you for guidance here, the RAW paradigm is a complicated thing. All we want to do, is deliver to the client, in a way that makes the Epic shine.

[Jannard]

The difference is that if you do an R3D based workflow you get to decide exactly what you want. With ACES... it decides the starting point. You work under that. And it is an aggressive starting point.

Jim

[Casey Green]

Looking forward to my own projects workflows, I'm hoping for the day that .r3d is the standard from end to end. Is that so crazy?

[Graeme Nattress]

The ACES rendering does indeed define a starting point. That will influence the final image and the direction grading takes, and that's inevitable on how these things work. If ACES is really really neutral in it's rendering (which the currently released RRT/ODT combo is definitely not) then grading will be possible to practically any style or look you want, and the influence of the starting point will be minimal. I don't think ACES can meet that neutrality goal today with the software that testers have to use. We try really hard with our default renderings to keep neutrality in mind. A grey scale is grey without colour shift, for instance.


Graeme

[gbalaji]

I had the same experience of rendering through ACES workflow of same image from Arri Alexa - ProRes & ArriRaw. QT ProRes renders more saturated and biased skin tone where as ArriRaw renders clean image.

Definitely would say ACES is still in beta and its not advisable for production ready yet!