ACES + composite modes + exporting EXRs without an ODT + potential Resolve bug?

Discussions - Using ACES
1

Hi,

I’d like some guidance on the following problem, but before that, some context:

I work in Resolve using ACES 2.0/AP1/ACEScct on a project-settings level with the ODT set to Rec. 709. Very straight forward. I export all of my projects as EXRs (RGB half zip) without an ODT (so basically, linear).

The issue/bug (simplified here) I encounter is as follows:

  1. I place a clip on the timeline.
  2. On the color page, I add a node and change the node’s composite mode to Multiply.
  3. I disable the ODT and render out EXRs.
  4. I import the EXRs and re-enable the ODT to 709.
  5. I place the export EXRs above my original clip. The two clips don’t match.

I am pretty sure it’s a Resolve bug. Can anyone else confirm?

2

What is the purpose of the multiply?

3

I use it for a specific reason, but I don’t think that’s really important. Someone might use another type of composite mode for some other reason. I’m just trying to find out why this effect “breaks” when exporting EXRs without an ODT.