Sidebar: Understanding VR resolution
Excerpt from Sidebar: Understanding VR resolution, page 190:
...Because 360˚ video is stretched out from a latlong file and projected onto a virtual sphere for viewing, even high-resolution files can appear soft and blocky during playback. To better understand why VR resolution often seems so low, remember that during playback the data from the image must cover a sphere all around you, but you’re only looking at a small portion of that sphere at any given time.
In fact, most VR viewers display a field of view between 90–110°. That means you’re viewing only about ¼ of the image at any given time—or put another way, the source image must be approximately 4 times larger than your screen resolution in order to appear fully sharp.
So, if the resolution of the device you’re viewing is 2560 x 1440 (as on a Samsung Galaxy phone) and your field of view is 96° (as on the Samsung Gear VR, which converts the Galaxy into an HMD), the video file should ideally have a resolution of approximately 5080 x 2880. Unfortunately, this is larger than the maximum 4096 x 2048 resolution that Gear VR supports...