A farewell to the ACES colorspace, Hello C13 (Patreon)

When I first endeavored to write my custom tonemapping functions after CSP 0.1.80preview200+ made that possible, I was obviously out of my depth. The great thing about code is the freedom to experiment. As you may have noticed, C13 Aegis doesn't look quite like other filters. That's due to two things:

• A fully custom tonemapping function (math yay)
• Using the ACES colorspace as the intermediary within which the tone mapping is being done

My math makes it possible for me to live modulate the mapping curve in the way I need to, to maintain the intended visuals. And the ACES colorspace made it possible to blow out taillights towards orange rather than white. And that's a look i like a lot.
But there's always a but.
Apparently this is a known thing, but the aces space shifts yellows quite a bit. This is mostly due to the aim of the space being a consistent, rather than accurate, color reproduction across different display devices. Here's a sample of the degree of difference:

The ACES and C13 shots are made with identical settings, with the exception of the color space used for the mapping curve application.

But maintaining color is easy, one simply needs to not over-compress during the transform. Now we must recreate the orange blowout. Analysis of the ACES matrix reveals that reds are compressed towards greens, and indeed, applying a similar compression, results in the desired look almost immediately. Some fine tuning later to neutralize the grays, and here we are. 

Agressively dependable yellows even at high brightness:

Some things will need to be adjusted to allow for an early access release, but this is coming soon!

Stay tuned and thank you.