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Top DIT/Workflow Supervisor Francesco Giardiello talks about his experience with ACES and how it benefits large and small productions.
Q: On what productions have you used ACES?
A: My first experience with ACES (pre-release version 0.7) was on Warner Bros.' Pan (Dir. Joe Wright DP. Seamus McGarvey). Production started at the beginning of April 2014 and finished at the end of the same year. Thanks to Sean Cooney's support (former SVP of production & post-production technology at Warner Bros.), with close support from the Academy, plus the encouragement and expertise of Peter Doyle, Joshua Pines and Chema Gomez from Technicolor, we realized on Pan, for the first time, a full and consistent ACES color pipeline from the set into post for a multitude of different cameras.
Right after that, I started working another major studio release, which I’ll call Untitled since it hasn’t been released yet. We shot this feature in early/mid 2015, and long with the same Dream Team, we continued to explore the benefits of ACES working with its first production release, version 1.0.
Q: This next film was a complex production involving lots of companies and platforms. Can you briefly describe the workflow and what was done to ensure that things ran smoothly on the set and in post?
A: At the first technical meeting with the cinematographer, it was clear that a single camera model workflow wasn’t going to work. In order to accommodate the director’s style we had to be able to put cameras everywhere, using all sort of different technologies, all running together. It meant a huge multitude of different color pipelines that, without ACES, we would have had to match and change on shot-by-shot basis, generating an enormous amount of work not just on-set, but especially in post-production. Previous movies had the same issues to address, and we put a lot of effort into developing a pipeline that helped us deal with a multi-source input.
But Untitled is a different kind of animal: it's a way bigger production, with way more VFX integration, more cameras, more production units and a considerable amount of vendors handling media every day. When you have so many people working on the same project it's very difficult to give the right instructions to every single one of them on how to treat the footage (or to configure the cameras to create the right footage) in order to achieve a seamless workflow and avoid technical issues that, at the end of the day, may create problems in the picture.
Another important factor to describe is that the cinematographer is used to working on set generating ASC CDL values on the live picture, baking-in his look and then expecting to see it back in the DI suite. But between two or three units, shooting at the same time in different locations and on different scenes, it's very hard to take control of the footage generated every day over 24 shooting weeks. Plus, you don't want to over-complicate the CDL workflow, otherwise VFX, post vendors and producers will lose confidence in it - as we all know, that has happened on some shows - and they will stop using it.
Live grading through CDL is meant to be a simple process to provide a simple look on set, but if you start generating one CDL for every different take, for any different camera, on every different light condition, the post-production will end up having hundreds and hundreds of CDL value sets, creating a massive need for time and effort to make everything work, trying to understand the real artistic intent. That will most likely generate a mess for something that, in concept, should be very easy-going. Not considering the VFX side of it, where during the compositing process, very different live action and CGI elements come together in a single shot, once again maybe shot from different units, on different locations, with different cameras.
In these cases it is essential to have an established pipeline and, more importantly, a guideline - so not just different source inputs but a look to apply to them all, seamlessly, without needing to be adjusted every time. Also, this color pipeline needs to work perfectly in the interaction between each stage of production; that means having the same visual result for different output devices and platforms, which brings a whole bunch of other different issues to address, including but not limited to compression steps, hardware limitations, environment differences and “back and forth” turnarounds.
After our experience on Pan, and due to the great improvements on the ACES framework in the production release 1.0, we thought that ACES was our number one answer to address any possible mistake or uncertainty within the pipeline. So, we had a pre-production meeting only few weeks before we started the principal photography, where we again involved Technicolor, with the Dailies Technical Supervisor Chema Gomez and, as per Pan Peter Doyle supervising the whole imaging pipeline.
We also involved our main VFX vendors and our VFX and Editing Team in designing the entire workflow. We established 12 different camera data formats that were defined for the 6 cameras used on-set. Those camera formats were tracked though a database that was linked to a set of instructions to define how to pull each “target frame” from each source, e.g., recorded frame size, what Input Device Transform (IDT) to use, therefore covering both image resolution and color pipelines. ACES 1.0 introduced the ACEScc and ACEScg working color spaces, which simplified incredibly the interoperability within the ACES framework.
On Pan we had up to 11 LUTs to process the pictures, which included the transformations from and to ACES2065-1 (the primary ACES encoding) and to a custom log-based ACES encoding and to ACESproxy (the lightweight on-set encoding). It was a bit overcomplicated.
With ACES 1.0, the Academy took a step forward in simplifying the process so, since the first pre-production meeting we were all in agreement about how and what to use. The color pipeline was designed like this:
- IDT to transform camera RGB values into ACES2065-1;
- a transformation process for the “intermediate” stage, according with the working environment (ACEScc for set and dailies/stage, ACEScg for the VFX);
- ASC CDL for the look for each camera;
- a transformation process to go back to ACES2065-1;
- first stage display transform: Look Modification Transform (LMT) + Reference Rendering Transform (RRT – a core ACES component)
- Final stage display transform, or Output Display Transform (ODT) specific to the display device.
Only stage 1 changed from camera to camera, the rest was identical for all cameras.
For processing tools unable to use simple 3x3 matrixes, such as on-set color management devices, Technicolor, under the supervision of Josh Pines and Peter Doyle, provided 3D LUTs that combined a few key processes together, collapsing the pipeline in basically three steps: an IDT LUT, the CDLs and the Display Transform LUT.
To sum up, using an ACES 1.0-based workflow, we were able to use the same CDL values generated on-set for both VFX and DI stages, providing a consistent and interoperable reference. Through the CODEX metadata system I've been able to embed each CDL in each shot, avoiding any manual link between the footage and the relative metadata that might have caused possible mismatch in the process.
All these aspects were described within a workflow document that was then shared with each of the production and post departments.
Q: If you were going to offer one piece of advice to a fellow DIT or a DP shooting his/her first project with ACES what would it be? What should every DIT know about using ACES?
A: I would say that ACES is not something created only for major motion picture movies. It is actually more effective and useful on small productions and independent films. Hollywood studio movies and every big show has its team of people working in the background making sure that the color science and the others technical aspects of the workflows are well-prepared and fulfilled.
ACES is meant to stop the nonsense of having every day something new, unpredictable and unmanageable unless you are a master in this sort of things (and you have the time and the money and the support as well). ACES is the color scientist watching your back and assuring you that your pictures will look fine everywhere in the world, no matter what camera you using or what color grading system and what lab is processing your pictures.
And, once again, ACES is not only about color: it's a framework and is meant to cover many different aspects of your workflow. So, the more we use it, the more widely ACES will expand and the more topics it will cover (I hope so!).
So don't be afraid of studying it and using it and I'm sure that in a very few years we will have finally the safe playground for every present and future technology we always wanted.
Francesco Giardiello designs and executes workflows for major motion picture and television productions worldwide. His credits as a digital imaging and workflow supervisor include the upcoming feature films The Young Messiah, produced by 1492 Pictures, Ben Hur from Paramount Pictures as well as the 2014 release Black Sea for Focus Features and Film4. Among Francesco’s many projects as a digital imaging technician (DIT) are Warner Bros.’ Knights of the Round Table: King Arthur, The Man From U.N.C.L.E and Pan, Marvel Studio’s Thor: The Dark World and HBO’s Game of Thrones.