4K resolution

4K resolution refers to a horizontal display resolution of approximately 4,000 pixels. Digital television and digital cinematography commonly use several different 4K resolutions. In television and consumer media, 38402160 (4K UHD) is the dominant 4K standard, whereas the movie projection industry uses 40962160 (DCI 4K). The 4K television market share increased as prices fell dramatically during 2014 and 2015. The term "4K" is generic and refers to any resolution with a horizontal pixel count of approximately 4,000. Several different 4K resolutions have been standardized by various organizations. The terms "4K" and "Ultra HD" are used more widely in marketing than "2160p". While typically referring to motion pictures, some digital camera vendors have used the term "4K photo" for still photographs, making it appear like an especially high resolution even though 3840×2160 pixels equal approximately 8.3 megapixels, which is not considered to be especially high for still photographs. In 2005, Digital Cinema Initiatives (DCI), a prominent standards organization in the cinema industry, published the Digital Cinema System Specification. This specification establishes standardized 2K and 4K container formats for digital cinema production, with resolutions of and respectively. The resolution of the video content inside follows the SMPTE 428-1 standard, which establishes the following resolutions for a 4K distribution: 40962160 (full frame, 256135 or ≈1.901 aspect ratio) 39962160 (flat crop, 1.851 aspect ratio) 40961716 (CinemaScope crop, ≈2.391 aspect ratio) 2K distributions can have a frame rate of either 24 or 48 FPS, while 4K distributions must have a frame rate of 24 FPS. Some articles claim that the terms "2K" and "4K" were coined by DCI and refer exclusively to the 2K and 4K formats defined in the DCI standard. However, usage of these terms in the cinema industry predates the publication of the DCI standard, and they are generally understood as casual terms for any resolution approximately 2000 or 4000 pixels in width, rather than names for specific resolutions.