Key Differences Between 4K and UHD Resolutions
High definition (HD) resolutions (1920x1080) and DVI singlelink resolutions (1920x1200) have become commonplace — at home, on desktops and on video walls. However, the term “4K” requires some clarification, because “4K” and “UHD” have different meanings and correspond to different resolutions depending upon the vertical market. For the display market, UHD means 3840x2160 (exactly four times HD), and 4K is often used interchangeably to refer to that same resolution. For the digital cinema market, however, 4K means 4096x2160, or 256 pixels wider than UHD.
The reason for this wider 4K resolution, is that 4K digital cinema projectors must accommodate films that are produced in both “Flat” (1.85:1) and “Scope” (2:39:1) aspect ratios. The pixel resolution of Flat is 3996x2160, while the resolution of Scope is 4096x1716.
The choice of aspect ratio is determined by a film’s director and cinematographer, but the DLP® (Digital Light Processing) chip inside most projector engines is designed to accommodate both of these resolutions — the wider “scope” and the taller “flat.”
The DLP Chip accommodates two digital cinema film aspect ratios