In this tutorial we go over some ways we can utilize ACES in Octane 2020. Sadly as far as we know there is no way currently to navigate ACES inside of Octane itself, but we do have access to a new ACES EXR container file.
Given that we can’t adjust the ACES preview just yet inside of Octane, we’ll have to resort to continuing to correct our image in post.
In order to set up our ACES export we’ll need to look into the Octane render settings. Under the “Render Buffer Type” you’ll find all of the export types. These buffer types each align with the 4 different tonemap previews we get from the Octane live viewer.
LDR 8-bit = 8-Bit (deprecated)
HDR = Float (tonemapped)
HDR Linear = Float (linear)
ACES = Linear ACES2065-1
Once you select Linear ACES2065-1 you’ll see a new drop down appear with an outputted saved destination. This will export a new ACES EXR file, which is the file you’ll want to use when converting to ACES in later steps. Avoid using the addition save file you’ll get from the C4D output section.
Once in AE we’ll need to start setting up our project settings.
Right click on the imported image > Main > Interpret footage, and then got to the color management tab. You’ll want to be sure to uncheck the Preserve RGB button.
Next make sure your working in the right bitdepth. Click on 16 bpc (or 8bpc) down at the bottom of the AE project window (this is where you import files.) Change the depth to 32 bits, the working space to ACEScg, and then be sure to check “Linearize working Space.”
Finally place your image in a new composition. Click on View and make sure “Display Color Management” is left unchecked. Now your project should be ready for ACES conversion.
Using OpenColorIO we’ll need to setup the config files as well as our ACES inputs and outputs. If you need more clarification on this section you can view our previous ACES tutorial.
*input transform
*output transform
I put all of the export types through ACES to get an idea of how each compare against each other. Overall LDR, HDR, and HDR Linear exports looks pretty similar, with the exception of some subtle range differences in the blacks. The original ACES file came in very dark so I had to apply some corrections in order to see how it compares. The ACES EXR needed no additional corrections and looked very nice straight out of the gate.
I then did the same tests with a different type of image. The goal here was to see how ACES handles a scene with more color values. For this test I didn’t render out the LDR export. All images came in a little dark, so I did some corrections. With no shadowy distortions and vivid colors it’s clear that ACES EXR is the winner.
I had read in a blog post online that someone was recommending to bump all of the gammas in your diffuse textures within Octane to 1 instead of 2.2. Overall this gave the render a bit more of a punchy feel with some more contrast. The Gamma +1 EXR also came in a little flat so I added some saturation for comparison.
At the end of the day it was hard for me to really determine which image looked better, the ACES EXR or the ACES EXR Gamma +1. I personally don’t feel that bumping the gamma for every render is a going to be an intuitive workflow. Plus this only works for renders which utilize image textures. A shader created proceduraly would have no effect in bumping gammas.
