A pinball machine is a very vibrant and dynamic lighting environment. There are areas with deep blacks and areas with saturated highlights. We'll need a lot of flexibility to push the realism of our lighting, especially since we are going to be working in a real-time engine. ACES (Academy Color Encoding System), created by The Academy of Motion Picture Arts and Sciences covers the entire range of visible light (also referred to as the spectral locus).
Even though there is no monitor capable of displaying the entire range of visible light, ACES provides unmatched color grading flexibility. For a quick start on ACES check out ACES in 10 Minutes by Ben Cain on shootdatapost.com.
Thankfully, Unreal Engine has had native ACES support, but there are a few nuances to the process.
We'll need to be using an ACES lookup table in Substance Painter so that there aren't any surprises when we bring our textures into Unreal Engine. Brian Leleux, lighting artist at Crystal Dynamics generously offers one for free on Gumroad. Check out his Artstation post about using the LUT and download it here.
Once all is said and done, we'll need to export our final image with ACEScg color space to Nuke for compositing/color grading. (work in progress...)