Video file and display resolutions for VR experiences
I was trying to figure out an ideal video resolution to record VR video in, for my HTC Vive VR headset. By ideal, I mean what video file resolution would take full advantage of the display’s resolution.
I am asking myself this question because I don’t think the current state of technology has a good answer and I want to know what recording resolution do I need to max out the amount of recorded detail.
It’s display resolution is 1080×1200 per eye, with a field of view of 110deg side to side and 100deg up and down.
That means that side to side, to cover 360 deg the ideal resolution should be 3534px (360/110*1080).
Up and down, to cover 180deg, the per eye resolution should be 2160 px (180/100*1200)
So the ideal 360deg file resolution should be 3534 x 2160px per eye. For stereo video, the vertical resolution needs to double, so it beomes 3534 x 4320. That’s very close to 6k resolution (4,992 x 3,744, which is 18MegaPixels)
Everyone that’s tried a VR headset in 2017 will attest to the the fact that the display resolution is rather poor. But even with this ‘poor’ display resolution we need 6k (18 MegaPixel) video to take full advantage of it. 6k video files are massive and working with them is not a simple task from a computational perspective. Only the very best/most powerful machines can handle smooth editing at these resolutions. 7680×4320
If we want to increase that display resolution to get a less pixelated image in the headset display, we are also going to have to increase the recorded video resolution. So even a modest 1.4x increase in headset display resolution on both axis (which results in a 2x total resolution increase) means that we need 10k video to use the display’s full potential. Going to 2x increase in display resolution on both axis (so a 4x increase in total resolution) means… I don’t think we even have resolutions that go up that high… 20k resolution?
I could not even speculate on what kind of internet connection and bandwidth you would need to stream that kind of video file from youtube.
All this being said, while a 4 times increase in resolution of the display is significant, it does not come close to full potential of what the eye can see and distinguish.
The current 4k video streams available on youtube do not contain enough information to take full advantage of the display resolution in today’s generation of headsets.
One thought on “Video file and display resolutions for VR experiences”
You should read up on the nyquist frequency. When applied to digital images and displays it basically says that if you have an FHD display, a FHD video is overkill. You’ll never be able to see a single pixel detail of the video, because if you get close enough to see it, you’re already seeing the subpixel structure of the display. That is actually the biggest reason for having a 4k TV today – you’ll finally be able to watch all FHD movies with all the details visible – something that was impossible on FHD screens. So your calculations are OK, but just around 30% to big. I have a Sony Z5 premium with a 4k screen and I honestly can’t see a difference between a 6k clip from insta 360 and the same clip reduced to 4k. Even though if we follow your calculations I should be seeing a benefit from a 7k video resolution of the clip 😉