Don't know your WCG from your HEVC and HDR? Step this way
Home AV Article
3,136As television technology inevitably marches on so does the terminology associated with it.
It seems with every new major trade show, we are presented with new features and standards that soon become abbreviated, for the sakes of convenience, but these acronyms can be very daunting for the uninitiated.
So, we’ve been sifting through our articles, reviews and all the forum chat to collate all the most popular abbreviations and acronyms to lift the lid on what can be a confusing new world, we hope you find it useful.
Acronym Full Terminology Definition 4K 4K Although often used interchangeably with the term Ultra HD, 4K actually has a resolution of 4096 pixels wide by 2160 pixels high and it's what you might see at the cinema. The term 4K relates to the four thousand pixels of horizontal resolution. There are no Ultra HD TVs with a native 4096 x 2160 resolution but most can display this type of content. However some 4K projectors do use 4096 x 2160 pixels as their native resolution. 8K 8K The term 8K is only used in conjunction with Ultra HD resolutions and it has dimensions of 7680 pixels wide by 4320 pixels high. Like the use of the term 4K in relation to Ultra HD, it's actually a slight misnomer because 8K means eight thousand in reference to the number of lines of horizontal resolution; although 7680 is very close. DCI Digital Cinema Initiative We use the term DCI in relation to wider colour gamuts although it's not a TV standard at all. DCI-P3 is a projection recommendation for colour used in the cinema and is a wider gamut than Rec.709 (HDTV Colour) but not as wide as Rec.2020 (4K UHD TV Colour). Despite not being a TV standard, it is useful to measure against to give an indication of the breadth of a TV’s native colour gamut. DV Dolby Vision A version of HDR developed by Dolby with enhancements made through added data available to a Dolby Vision enabled display. Dolby Vision is included in the specifications for Ultra HD Blu-ray and has been adopted by a number of studios and TV manufacturers. EOTF Electro-optical Transfer Function This term relates to how a display turns digital code into visible light on its screen and is also referred to as the gamma curve. FALD Full Array Local Dimming All LCD TVs need a backlight to make the pictures bright enough to view. Most now use LEDs as the backlighting source and some of the higher-end TVs carry a backlighting system known as Full Array Local Dimming which means the LEDs are placed directly behind the panel - and not at the edge like some lower-end TVs. These LEDs form part of local dimming system which attempts to make the darker portions of the picture darker by turning off specific LEDs to improve the native black levels of the technology. The more dimming zones within a FALD system the better/more accurate, in theory, it should be. Full HD/1080p Full HD We usually refer to a TV with a 1920 pixels wide by 1080 pixels high resolution as either Full HD, 1080p or just plain HD (High Definition) although the latter term is far from definitive (see HD Ready below). HD Ready/ 720p HD Ready A TV with an effective resolution of 720p - usually, but not always, 1280 pixels wide by 720 pixels high - is known as HD Ready. You will be very hard pressed to find an HD Ready TV in anything but a very small screen size nowadays. HDCP 2.2 High-Bandwidth Digital Content Protection HDCP is a copy protection measure implemented throughout the industry and for Ultra HD content, your equipment must support the latest version, 2.2, or the content won’t play. Older equipment will only comply with HDCP 1.4 so it's worth checking the specifications thoroughly. HDMI 2.0(a) High Definition Multi-media Interface To display Ultra HD pictures at anything over 30 frames per second, from connected equipment, your TV must have an HDMI 2.0 connection. If you want to show HDR video, the connection type must be HDMI 2.0a; this information should be available at point of sale and/or on the manufacturers website product page. HDR High Dynamic Range A way of encoding and displaying video which then produces pictures with much brighter highlights and more details in the dark sections of the video than conventional (SDR) material. The term dynamic range relates to the difference between the darkest and brightest part of the image. HDR10 High Dynamic Range 10 This is an open platform version of HDR that has been included by the Blu-ray Disc Association (BDA) in the specifications for 4K Ultra HD Blu-ray. HDR10 content is compatible with all HDR displays and has been adopted by a number of TV and projector manufacturers, as well as certain studios. HEVC High Efficiency Video Coding HEVC stands for High Efficiency Video Coding and is the new video compression standard that has been developed primarily for delivering 4K, either via streaming or on Blu-ray. By using HEVC coding more information can be compressed more efficiently, allowing 4K content to fit onto a Blu-ray or be streamed over a broadband connection IPS In-Plane-Switching Broadly speaking there are two types of panel used in LED LCD TVs - IPS and VA. IPS panels can boast wider viewing angles than VA panels but their black level and contrast performance isn’t as good. LCD Liquid Crystal Display All TVs marked as LED or LCD actually use Liquid Crystal Diodes (tiny lights) for the pixels. LED TVs just use Light Emitting Diodes as the light source to illuminate the pixels, rather than the less energy-efficient CCFL backlighting type. In terms of consumer LCD TVs, these days virtually all of them use LED backlighting. LED Light Emitting Diode There is no such thing as an LED TV, really, as said above LEDs are just used to provide the backlight - LED TVs still use an LCD panel. nits/cd/m2 Nits/Candela per Square Metre Nits and cd/m2 are both ways of expressing units of light measurements and 1 nit = 1 cd/m2. To gain accreditation as a UHD Alliance Premium TV, a set must be able to hit a maximum light output of 1000 nits with a black level no higher than 0.05 nits or hit a peak luminance of 540 nits with a black level no higher than 0.0005 nits. In reality, the former is a standard for LED/LCD TVs whilst the latter is currently only achievable by OLED TVs OLED Organic Light Emitting Diode In contrast to TVs marked as LED, OLED TVs really are something new. An OLED requires no help from a backlight as it is self-illuminating and, unlike LED LCD TVs, the pixel can be switched completely off meaning OLED TVs have much better black levels and contrast performance than LCD TVs QD Quantum Dot The majority of TVs displaying Wider Colour Gamuts (WCG) use quantum dot technology to achieve them. A layer of quantum dots is placed in front of the backlighting, allowing them to produce a broader colour spectrum. Rec.2020 ITU-R Recommendation BT.2020 This is a series of standards created for Ultra HD TV production and distribution but is most often mentioned in reference to the colour gamut, which is much wider than Rec.709. Rec.709 ITU-R Recommendation BT.709 This is the standard adopted for HD TV (not Ultra HD) production and distribution and includes a colour gamut much narrower than Rec.2020. SDR Standard Dynamic Range All video content that isn't labelled as HDR is Standard Dynamic Range (SDR) material, i.e. everything you've been watching until 2016. SMPTE 2084 Society of Motion Picture and Television Engineers 2084 This is the technical standard pertaining to the EOTF for HDR video and, specifically, it describes how to turn digital code into visible light on-screen. SMPTE 1886 relates to the EOTF for SDR content. They aren’t something you need to worry about but at least if you see it mentioned you'll know what they mean. UHD Ultra High Definition With at least twice the resolution and four times the pixel count of Full HD, UHD is now the de facto resolution in all the popular TVs. UHD is often referred to as 4K which is the standard used in cinema and has a slightly different resolution (see above). There are, in fact, two Ultra HD resolutions specified: 3840 x 2160 (4K UHD or 2160p) and 7680 × 4320 (8K UHD or 4320p). UHDA Ultra High Definition Alliance Comprised of major Hollywood studios, consumer electronics companies, content distributors, post-production services and technology companies, the UHD Alliance has set out an end- to-end standard for devices and content to qualify them as UHD Premium. If a TV is labelled as UHD Premium, it means it meets a demanding set of standards regarding picture quality. VA Vertical Alignment Broadly speaking there are two types of panel used in LED LCD TVs - IPS and VA. VA panels have a better black level and contrast performance but they have a narrower viewing angle compared to IPS panels. VP9 VP9 VP9 is another video coding format developed, this time, by Google. The relevance of VP9 is that it's the format used for Ultra HD/4K video on YouTube. So if you want to watch that content, your TV will need to be able to decode VP9. WCG Wider Colour Gamuts Up until now, when watching video content at home, you have been viewing a relatively narrow spectrum of colours. This is due to the technological limitations of the Rec.709 colour gamut that is currently used. Going forwards, content will be released adhering to the Rec.2020 standard which will provide a far broader spectrum of colours and, therefore, more realistic images. There are currently no TVs capable of displaying the full Rec.2020 standard but the manufacturers are getting ever closer to achieving it and many higher-end TVs can reach the cinema standard of DCI-P3.
So there we have it, around 30 acronyms busted and we're sure the list will grow as new technologies are announced and released but, in the meantime, if you think we've missed anything or there's something you would like to see explained, please don't hesitate to shout up in the comments...
To comment on what you've read here, click the Discussion tab and post a reply.