It's a touch decision to make. I can render the VR360 at 4k ( 3840*2160) mono, or 2160*2160 stereo. the last 3 VR360 projects were the later.
let's put the render time at the side for a moment. I can't go higher than 2160*2160 on the stereo, because my video editing software won't output anything with a longer *width*. now one would think that the 4k mono will contain much sharper details, as it should: it's not only higher in res, it's also mono, while the 2160*2160 is stereo - which means each eye gets actually half of that...but...again, I rendered both and viewed them one after the other on my VR-helmet...
the change in resolution wasn't something striking...but the illusions of depth punch you in the face right away. so...I think I'm sticking with that, and take another comfort on the fact that this one will also be rendered for a none-VR version - and there I'll blast in 1080P or maybe even 4K (depends on if there will be animated sequences, or more accurate: how many of them + how many frames).
what do you guys think? I'm still using VR-gear + iphone7, but I ordered an Oculus go, so my experience will be improved soon, I hope and maybe I could tell the difference in resolution better.
here are the two versions. thanks!
*side note: the stereo version got less cycles, also. it will be as clean as the 4k one, just lower in res!
*Edit: some good news! I can crank it up in stereo, to around 2560*2560, so we go up on res AND keep the stereo :)