ACES in Action Part 2 – Breaking Down the Imaging Pipeline

Very well detailed history, reasoning, and processes. Fascinating.

Perhaps a sgnificant part of the benefit of using ACES was simply the forethought it required brought to pre-planning the entire process?

Would you Please do it in a video .a complete workflow on ACES in davinci resolve for color grading .

Thanks Neil! I definitely think that the pre-planning required to implement ACES is incredibly valuable to an indie film. It forces you to be intentional about your entire workflow, something that doesn’t always happen on smaller projects.

Hey Peder, first of all great great article! For me specially helpfull since I’m considering ACES for an upcomming project myself! A project that also has some planned vfx!

VFX – DaVinci Resolve / AfterEffects
Resolve
Conform VFX pull lists to the original footage, re-applying image reframing if necessary
Turn off ACES Rec709 output transform (placing the footage in ACES AP0 linear space)
Export each plate as a 4096×2160 OpenEXR 16bit Half-Float image sequence

Did you disable you dailies grading before handing of the plates to VFX?

In the few edge cases of under- and over-exposed clips, I found the RED RAW controls to be a better method of adjusting exposure than Resolve’s Log or LGG tools. Adjustments in the camera RAW panel happen prior to the transform into ACES AP0 space and yielded cleaner highlight and shadow recovery, to my eye.

I don’t know why it never clicked for me but, ACES does not make sense if you don’t have RAW footage, right? I work 90% with super well shot Arri 4444 footage, but even then, when I try to do the project in ACES, some moodier clips or under exposed ones, clip below a certain threshold and that data is not recoverable. [I could just bypass the IDT or select 709 (whit a 709 ODT) so that no transform is applied, but that it a last effort solution and not really viable.]

Apparently this film has a lot of very dark scenes and you managed those by dialing in the raw settings, but did you ever encounter clipped data that you could not get back without going into the raw tab?

Finally, is there a trailer we can watch? The look appears to be really cool!

Best!

Hi Jose! I’m glad the article is helpful. I figure there are a lot of people that want to try ACES but need a little help getting the workflow right.

Did you disable you dailies grading before handing of the plates to VFX?

Yes, I generally disabled the dailies grade before exporting the VFX plates. In a few cases, I did a little balance work on the plates pre-export in order to give the VFX artists a good starting image to work from. But in either case, they were exported as ACES AP0 Linear EXRs with the OT turned off.

ACES does not make sense if you don’t have RAW footage, right?

ACES will work just fine with non-RAW footage as long as it conforms to a known camera profile with an existing IDT. In fact, that’s what the IDTs are for, since Resolve decodes RAW clips directly into ACES AP0 space without using an IDT.

In your case, it might make sense to use a node-based ACES implementation instead of applying the IDTs to clips in the bin. That way, you can place a trim node before the IDT node and make exposure adjustments there.

did you ever encounter clipped data that you could not get back without going into the raw tab?

I definitely took advantage of all the raw controls to get the R3D footage in the right place for grading, so the only clipping I saw happened in-camera.

Finally, is there a trailer we can watch?

Great question! The trailer will be released in about a week, so I’ll post it here once it goes live.

Quick question. The EXRs you deliver to VFX… those had the raw settings of the .R3ds baked in right? Did you ever need/wish you had access to the raw data? I can imagine a scenario where you would have maybe had specific raw settings applied to a bunch of clips, but then a VFX clip or two in the scene that might have been harder to match…

Great question. I took special care with the RAW settings when exporting the VFX plates to make sure that they provided a good starting point for both the VFX artists and the final grade. It also helped that the original material was correctly exposed and color-balanced, meaning that I wasn’t making large adjustments using the RAW controls.

Using this workflow, the final VFX shots dropped right into the grading session with very little adjustment. It just took a bit of advance planning.

That’s kind of what I figured would be the best approach. Thanks for letting me know.

The trailer looks amazing.
HOAX: https://youtu.be/1nKOJJa-b5U

Thanks for writing this series. Very well explained and motivating! I’m looking forward to the HDR chapter. Keep it up!

Great article and very thorough Peder, thank you!

I’m currently grading a feature in ACES shot on both Alexa and RED Monstro, I’m getting VFX renders from the VFX sup, done by various vendors, some are delivering DPX, others prores 4444, now I came onboard a little late after all VFX was done and after I had set my looks on the RED files I ran into the problem of not being able to select an IDT for the VFX renders because RED was processed as RWG Log3G10 for VFX plates. If I’m outside ACES (non-color managed project) there’s no shift between the RED in LOG and the actual VFX render, but I’m in ACES. What do you recommend I can do at this stage to just drag and drop the grades I had built working on the RED raw to the final VFX renders without having to rebuild my grades from scratch?

Thanks Oliver! I’m glad you enjoyed the article.

Its always difficult working in ACES when you don’t have a unified VFX exchange process. Ideally, the VFX vendors would have been working in ACES, exporting APO EXRs instead.

You could potentially use a color space transform to convert the VFX plates from RWG Log3G10 to ACES space, but the results may vary enough that your original grades may not work. You’ll have to test it.

Thanks Simon! We should be finding out about the HDR version soon.

The trailer for Hoax has finally been released. Here it is:

https://www.youtube.com/watch?v=oMAbHG2UoYs

The film will be released August 20th 2019 on all VOD platforms, including iTunes, PlayStation Network, XBox Live, Vudu, Comcast, Cox Cable, DirecTV, Dish Network and more. SVOD to follow later this year.

That’s awesome. I do have just a question, how did you deal Lut on set ? Have you built a creative Lut during prep?