8K UHD
An ultra-high-definition image format based on a 7680×4320 television system standard, with a total number of pixels approximately four times that of 4K UHD and sixteen times that of 1920×1080.
Explanation
8K UHD is an image format with a resolution of 7680×4320 in the Ultra High Definition (UHD) television system; it is twice the horizontal and vertical resolutions of 3840×2160, with a total of approximately 33.18 million pixels. ITU-R BT.2020 includes it, along with 4K UHD, in the parameters for Ultra High Definition television production and program exchange. 8K refers only to the spatial sampling level. The BT.2020 standard also covers progressive scanning, frame rate, primary colors, and bit depth; however, a file labeled as 8K does not necessarily have to utilize the full BT.2020 color gamut, HDR, or high frame rates. Encoding may use HEVC, VVC, AV1, or other suitable schemes, depending on the distribution system.
In the digital cinema field, “8K” may refer to other aspect ratios with approximately 8,000 horizontal pixels; scanned footage may also vary in size due to film gates, cropping, and restoration. 7680×4320 is a 16:9 television aspect ratio; not all images with a width close to 8,000 pixels can be considered to meet the same standard. Effective detail is limited by cinematography, lenses, sensors, master copies, and compression. 8K releases may be upscaled from lower-resolution source material, and 8K scans may also be downsampled to produce 4K or 1080p. Viewing benefits also depend on screen size and viewing distance; file resolution does not guarantee that viewers will be able to distinguish every pixel.