Notice of Meeting - ACES Gamut Mapping VWG - Meeting #16 - 6/11/2020

ACES Gamut Mapping VWG Meeting #16

Thursday, June 11, 2020
9:30am - 10:30am Pacific Time (UTC-4:30pm)

Please join us for the next meeting of this virtual working group (VWG). Future meeting dates for this month include:

  • 6/18/20 5pm
  • 6/25/20 9:30am

Dropbox Paper link for this group:

We will be using the same GoToMeeting url and phone numbers as in previous groups.
You may join via computer/smartphone (preferred) which will allow you to see any presentations or documents that are shared or you can join using a telephone which will be an audio only experience.

Please note that meetings are recorded and transcribed and open to the public. By participating you are agreeing to the ACESCentral Virtual Working Group Participation Guidelines

Audio + Video
Please join my meeting from your computer, tablet or smartphone.

First GoToMeeting? Let’s do a quick system check: []

Audio Only
You can also dial in using your phone.
Dial the closest number to your location and then follow the prompts to enter the access code.
United States: +1 (669) 224-3319
Access Code: 241-798-885

More phone numbers
Australia: +61 2 8355 1038
Austria: +43 7 2081 5337
Belgium: +32 28 93 7002
Canada: +1 (647) 497-9379
Denmark: +45 32 72 03 69
Finland: +358 923 17 0556
France: +33 170 950 590
Germany: +49 692 5736 7300
Ireland: +353 15 360 756
Italy: +39 0 230 57 81 80
Netherlands: +31 207 941 375
New Zealand: +64 9 913 2226
Norway: +47 21 93 37 37
Spain: +34 932 75 1230
Sweden: +46 853 527 818
Switzerland: +41 225 4599 60
United Kingdom: +44 330 221 0097


  • @joseph asked if the gamut mapping algorithm would be a required component of an ACES 2.x pipeline, @matthias.scharfenber proposed the “opt-out” scenario, which would cover the case of a ‘more accurate camera’ proposed by Joseph
  • @Alexander_Forsythe brought up that the documentation - both technical and user guides - will need to be robust. We hope that the need for end user documentation will be minimal, if the gamut mapper “just works”.
  • For invertibility - can we guarantee that all processing will be happening in float? No - but we should definitely encourage it, and most modern systems should already operate in full float.
  • @jedsmith brought up the different use cases for the algorithm - on set, VFX, and DI being the main three. Are there different needs in each place or are they equal?
    • Jed points out that having more parameterization options would be useful for VFX in particular, to tune based on input
    • @carolalynn points out that ACES is by design immutable, and we don’t have a way to track these parameters effectively
    • @KevinJW had a great example - sharing parameters with different vfx houses sharing shots would be a nightmare
  • Matthias mentioned that another potential use case for an “opt-out” non-gamut mapped transform would be to provide version compatibility between ACES 1.x and 2.x. Carol suggested later that “opt-out” should be referred to as the “legacy transform” instead.
  • Joseph - should we have a guide and versioning info for productions?
    • Carol - yes - ala VFX reference platform expanded, and CLF reference implementation example for DCCs etc
  • @nick demoed Baselight BLGs in Nuke of different camera output transforms applied to gamut mapped images - thinking is to use different display transforms to make sure we’re not overlapping scene-referred mapping issues with display referred ones
  • Overall, this call circled around use cases, and when/if the gamut mapping operation should be applied. Look forward to a new post summarizing Carol, Matthias and Nick’s thoughts on where we stand on this crucial juncture soon.