Which linear colourspace

For 16 bit images I am going to move to an all linear workflow, before saving final display image in profile required. Given it encompasses all real colours, is there any reason I should not use ACES 2065-1 (AP0) for this?

To put it another way, what are the advantages or disadvantages of AP0 over AP1, linear Rec 2020, linear Pro Photo RGB, etc…

If you search the forum, you would find that it depends on your workflow and opinion about the spaces. The main challenge is moving from one space to another; in particular, going from a large one to a much smaller one at the end of the workflow (e.g., sRGB). Typically, I would use a just large enough, so the conversion won’t be so awkward. In my casual processing, I would say that linear Rec2020 fits that role, but your conclusion might be different, depending on what you want to accomplish.

3 Likes

I did search. I found only two other answers. One matching your thoughts on Rec. 2020 as being the best compromise. And another suggesting you should always set working profile to match output (without saying why - although the prevention of colour shifts is an obvious reason). I’m also aware there is generally a bigger is better argument, which is why a lot of people use pro photo RGB, but doesn’t explain why those people haven’t now switched to ACES AP0.

An answer may have been provided here:
https://www.colour-science.org/blog_about_rgb_colourspace_models_performance.php
Which I found through Nine Degrees Below:
https://ninedegreesbelow.com/photography/white-balancing-camera-jpegs.html#summary
But alas, its a 404. Actually, just found it on the wayback machine:
https://web.archive.org/web/20160412234235/http://colour-science.org/posts/about-rgb-colourspace-models-performance/

Based on delta-e value table, ACES AP1 and Rec. 2020 outperform the common RGB spaces by a small margin.

Considering all of the above I would probably settle on Rec. 2020, but I’m surprised more here haven’t chimed in with their own views.

Sometimes it takes more than 1 day to get answers. So be patient.

Rec2020 is a good option, anyway.

And if you’re talking about which working profile using in your raw processor, then a search in this forum gives a few more hits than just a couple…