When an image shown on an 8K display is projected onto the entire hemisphere, the size of a single pixel is almost equal to 1’, which is same as human visual acuity. This indicates that the resolution of an 8K display is beyond the visual ability of humans, in most cases. A display can show not only an image, but also coded information on its screen. When this ultra-high-definition display is used as a light-field display that consists of a high-definition display and lens array plate, its redundancy of resolution is used for depth information of 3D objects, and a volume 3D image can be reconstructed near the screen. We fabricate a 3D light-field display using a 4K cellular phone and obtain a good image quality. An 8K display is more suitable for a light-field display that generates 3D images of higher resolutions, although the reproduced depth is limited. Herein, I report our light-field display utilizing an ultra-high-definition flat display.