4K+ Systems: Theory Basics for Motion Picture Imaging

Five years ago digital cameras and cellphones were the biggest thing in consumer electronics, but the most popular phrase today seems to be “HD.” One would think that the “H” in HD stands for “Hype.” Although professionals have a clear definition of HD (1920 times 1080 pixels, at least 24 full frames per/sec, preferably 4:4:4 color resolution), at electronics stores, the “HD-Ready” sticker on hardware offers considerably less performance (1280 times 1024 pixels, 4:2:1, strong compression, etc.). On display are large monitors showing images that are usually interpolated standard-definition (720 times 576 pixels or less). The catchword HD for the living room means—on a different quality level—comparable to the discussion of 2K versus 4K in professional post-production—expectations, and sometimes just basic information could not be more contradictory. Yet an increasing number of major film projects are already being successfully completed in 4K. So, it's high time for a technically-based appraisal of what we really mean by 2K and 4K. This article strives to make a start.