We shot some HDRIs with a colorchecker on the floor and normalized the “50%” patch to 0.18 in Nuke.
0.18 because the ACES white papers are saying that middle gray is 0.18 and we are used to it from the old linear/sRGB workflow as well.
If we want to match that patch for example in Nuke in an intuitive way, then I would expect to create a constant with R=G=B=0.5 and convert it via OCIO colorspace from “Texture - sRGB” to “ACEScg”. The result is a value of 0.214. Which makes sense somehow, but here is the point where my confusion begins.
Is this the value we actually WANT to get and if not, how do I archive the right value (besides typing in “0.18”)?
There are a lot more questions around this topic, but first off I would like to understand this “simple” context.