Thanks for asking, MaverickMongoose.
In short, ACES is great, and the shortest answer to going back to LW, how have you handled gamut-compression and tone-mapping back then?
OR was the screen sRGB, and didn't show all the color and brightness clippings? I hope that doesn't sound pretentious, not my intention. If so, sorry!
I hope I can stop myself soon enough. Here is my apology already 😉
Please note that is my personal opinion and not an official idea of Maxon-One. Ask ten people about ACES or LW; you might get 11 answers.
The idea and need for ACES were based on the growing use of digital cameras on film sets. Some sets use dozens of cameras, each with different Color Science and Sensor response characteristics.
The core idea was to define an ideal camera and screen while allowing any data to be stored in the ACES 2065 Color Space.
Since then, each camera manufacturer has produced an IDT (Input device Transform) to get the data produced as close as possible to the"Ideal Camera," with the target of mixing and matching any camera used on a set.
Which leaves the constant match of which camera to which discussion.
Following a rigorous and precise conversion into the ACES space, the exposure is expected to be clearly created. Otherwise, we would start to match this everything again.
Notice what is missing already? Yes, whatever you do, no light meter, gray card, or even precise Color measuring (Sekonic C800, for example) is given. Virtual MacBeth charts are kind of useless in this regard, as they are based on RGB-three channels, not pigments with the exact color, but that matters. That is a long story, but the reason for many misconceptions I see on YouTube is that people measure, perhaps via Eyeballing or tell that when it looks good, it is good. If that would work, we could print out on a CMYK printer color charts [sic], but that would only show how well we reproduce a specific Cyan, Magenta, and Yellow, nothing in between.
I should stop here, even I have perhaps only touched on a few percent of the story. Yes, ACES 2.0 will be more supportive here.
But a few more points:
In 3DCG, we do not have to match cameras. My observation: no one cares about perfect exposure, comparable exposure, color temperature (matching all parts), most of the time it is eyeballing.
Moving forward, we got our stuff done (LMT, Look Modification transform), and we like to get it out. Then, all the problems start when a small space is the target. DVDs were typically in REC 709, a 30-year colorspace. It wouldn't be my suggestion, but widely in use. However, for ACES, the main idea is as before Cinema/Theatre, with projectors that cost six digits, which get calibrated more often than most people do with their own central viewing devices. So, not all the problems ACES solves, but having all the trouble when going into a small space? What's the point?
I answer that any REC 709 production will look pale and outdated when people get used to having well-timed HDR content when the screaming highlights and bleeding saturation calm down.
After this long introduction to your question, "Why not stay in linear light workflow?" Real linear light workflow is XYZ/RGB space (Absolutely not sRGB) and is based typically on floating point with no limitations. Nuke has this sorted out perfectly, for example.
How has that gotten material into SDR and sRGB/REC 709?
Perhaps you never were in real Linear Light space and used just like sRGB, the slightest color space currently used for production. Then the conversion was often less problematic. Sorry if my assumption is wrong here. Go to Cineversity old and check any project file older than five years, the color space is most likely sRGB (99%)! This is not LW.
Run things in DaVinci, the DaVince Wide Gamut, or ARRI C3, which is the typical transformation when people don't use ACES these days, and compare the results while setting up the Pipeline. IF you feel well there, this is a great place for color.
Log footage is more appropriate when you use DaVinci, but I'm not sure if that will work well in the future.
Example
https://community.acescentral.com/t/do-we-need-to-change-acescct/5320
How have you "tone-mapped or compressed the given data from Linear Light Workflow (LW) into REC 709? If that has worked for you, ACES is linear and floating point. So write ACES 2065-1 out, the Storage and Exchange format, and you have (compared to REC 709) very little difference to LW. From there, go the regular route. However, if the LW was based on sRGB or REC 709, it was not LW.
I believe that ACES is an excellent concept for teamwork and multi-camera production, but is it the best? I do not think so.
When I develop footage from my RED or my Canon log raw footage, and I do not need to match it with anything, why move out of the native gamut so early?
The idea of ACES and 3DCG and Compositing is way more complex than Camera matching in a pool. I am all in if all parts were, from the start, developed in a large gamut and preferably Linear, while also, for all components like textures and HDRI, the color temperature needs to be known. There are so many parts that I could fill days with it, and I believe no one wants to listen after a few hours 😉
The best idea is to use where you feel savvy with, and what will hold up in the next ten years on developing screen. Clients don't like to look old with their visuals.
Chees