From cave walls to modern computer screens, artists have dealt with the same simple problem: the world is round and canvas is flat.
For the most part, this is something easily compensated for and rarely noticed in daily life. As we focus on small areas of the world at a time the effect is minimized. But, as we zoom out to the wider world, and take in more of what is around us, we start to see the issue. Round worlds don’t fit on flat paper.
Another way to think about it is to imagine trying to take the skin off an orange and laying it flat on a piece of paper. No matter how hard you try, only the center part will lie flat and fill edge to edge; but, as you get towards the top and bottom of the orange, the vertical wedges lead to points leaving more space than peel.
Map makers discovered the secret long ago utilizing a process wherein they took the spherical world and laid it on a flat map by expanding the image to fill in the holes. This style of imagery is called equirectangular and looks like this.
Equirectangular Imagery is the same thing from the inside out. Your world view is 360 degrees in all directions. As you look left, right, up, down, or even behind you, you are seeing only a small part of the world that spherically surrounds you. Conventional art, photography and video capture only a small segment of that view, a few narrow degrees of horizontal and vertical image.
Modern computer photography records images as dots of color and light known as pixels. Detail in a photo, controlled by the number of pixels is called resolution. Greater resolution creates an image with enhanced clarity and detail.
Equirectangular imagery allows a you to choose the location you desire to look in within the 360 degree sphere of capture. It then must provide adequate resolution. To do that, Ultra High Resolutions must be captured so that the detail in every area is contained within the image.
An image resolution from a modern professional camera is 6,720 x 4,480 which means there are 6,720 maximum pixels in the horizontal image. An HD-Television resolution is 1,920×1080. Ultra High Resolution Equirectangular imagery (UHR-E) is limited only by current computer display resolutions at 65,535×65,535 pixels, allowing a higher resolution than Ultra HD, at any direction of view.