This is what 1920x1080 looks like in a 28K 3:1 aspect field:
A 90mm lens would have a 92º horizontal Angle Of View on this 186mm-wide sensor, roughly equivalent to a 12mm lens on the current RED One.
If you click on the image above it won't fit on a 30" Apple Cinema Display. And it's 1/8 res.
An 8-bit 28,000 x 9,334 image would be roughly 748 megabytes in Photoshop.
This isn't an imager size that RED made up, it's used in crazy panoramic cameras.