The Consumer Electronics Association has rubber-stamped "Ultra HD" as the designation for screen displays that quadruple the resolution of today's standard Full HD.
Where HD images are 720 pixels deep, Full HD offers 1080 and Ultra HD does 2160. This gives Ultra HD images a resolution of 3840 x 2160 pixels (8.3 megapixels).
Ultra HD has previously been known as Ultra HD, 4K or sometimes Quad HD. However, 4K is also used for a digital cinema standard with a slightly wider screen resolution of 4096 x 2160 pixels.
In 2003, NHK's research labs in Japan originally proposed 4K UHDTV (ultra high-definition digital television) and 8K UHDTV or Super Hi-Vision, which has a resolution of 7680 x 4320 (33.2 megapixels). This is 16x the definition of Full HD and similar to IMAX cinema screens.
Super Hi-Vision television has already been seen in the UK. The BBC used the format to show Olympics 2012 on large screens in Bradford, Glasgow, and London, as BBC News reported.
The CEA's 4K Working Group recommended the term "Ultra High-Definition" to define the minimum performance characteristics for UHD TV sets "to help consumers and retailers understand the attributes of this next generation of superior television and display technology beginning to roll out this fall".
Gary Shapiro, the CEA's president and chief executive officer, said in a statement: "Ultra HD is the next natural step forward in display technologies, offering consumers an incredibly immersive viewing experience with outstanding new levels of picture quality."
Ultra HD will be "prominently displayed" at CES 2013, the CEA's Consumer Electronics Show, in Las Vegas on January 8-11.
Whether there's any advantage to having an Ultra HD TV is open to doubt, and back in January, a CNet article explained Why 4K TVs are stupid for home use. At an 8-foot viewing distance, you'd need something like a 102-inch screen to see the pixels on a 1080p picture, so there's really no point in having 2160p.
Indeed, CNet's Geoffrey Morrison points out that, at a distance of 10 feet from a 50-inch TV set, "even 720p TVs have pixels too small for your eye to see". In other words, many TV viewers don't even need Full HD (1080p).
From TVs to PCs?
UltraHD and Super Hi-Vision obviously have commercial uses both for corporate displays and cinemas. However, it's not clear whether Ultra HD will have any impact on PC screens.
At the moment, the WQHD format (2560 x 1440 pixels) has a small percentage of users thanks to sales of Dell UltraSharp U2711 monitors and Apple iMacs, with the Dell UltraSharp U3011 going up to WQXGA (2560 x 1600). The Apple MacBook Pro's Retina Display pushes that further to 2880 x 1800 pixels, but on such a small screen (15.4 inches), it's essentially a marketing game.
Given 20/20 vision, a human eye can resolve roughly 1 arcminute (1/60th of a degree), so every display is a "retina display" from a sufficiently large viewing distance. For example, you can't see pixels on any screen, no matter how bad, from 50 feet. It is therefore possible to work out the viewing distance at which a particular screen becomes a "retina display", and there's a website to make the calculations.
A 15.6-inch Full HD screen with a resolution of 1920 x 1080 pixels becomes a "retina display" at a distance of 24 inches (61cm), and this is enough for most purposes. This is a higher pixel density than you get on a 27-inch iMac screen with a resolution of 2560 x 1440 pixels, which becomes a "retina display" at 32 inches (81cm).
According to the website, the 15.4-inch Apple MacBook Pro's Retina Display becomes a "retina display" at a viewing distance of 16 inches (41cm). If the MBP were upgraded to an Ultra HD screen, it would become a retina display at 12 inches (30cm).
In sum, there is no advantage to moving from Full HD to Ultra HD on a 15.4 or 15.6in screen unless you have 20/20 vision and normally view it from less than 24 inches (61cm). Even then you might not be able to see any difference. However, there are also disadvantages, because each screen requires 8.3 megapixels instead of 2.1 megapixels. This means more graphics processing power, uses more memory, creates more heat, and shortens battery life. To handle the MacBook Pro's Retina Display, Apple increased the battery from a 63.5-watt-hour version to a 95-watt-hour battery.