Previously, I made a post listing the technical details of the PS4 patch.
That was a work-in-progress, and I said at the time I'd post final specs as soon as we know them, which we now do.
We are definitely supporting HDR, on both the PS4 Pro and the base model PS4. If the game detects an HDR TV, it will start in HDR mode. HDR works in all resolutions mentioned below.
If you have a PS4 Pro, and are outputting to a 1080p TV, The Witness will render at 1080p, 60fps, 4x MSAA (which is substantially higher than the base PS4's 900p, 60fps, 2x MSAA). This is the same as we announced in the earlier posting.
If you have a PS4 Pro, and are outputting to a 4k TV, then you get a choice of two modes from the options menu:
(a) 1440p 2x MSAA rendering of the game world, upscaled to 4k, text and UI rendered at 4k, 60fps
(b) 4k 2x MSAA rendering for everything, 30fps
We added option (b) because a lot of people seem to want it, and it does look really good!
I don't yet know the exact release date for the patch, but it is coming pretty soon, in November sometime. We are now in the process of nailing down all the little details and making sure they are good. As soon as we know the release date I will announce it here.