(Pocket-lint) - Television manufacturers release new models at least twice a year and the technology in their latest sets is constantly improving. It can be hard to keep up at times.
Even if you've bought a new TV recently, you might not know what it is truly capable of; what all the badges and logos on the box actually mean.
That's why we explain some of the most important new TV tech buzzwords to help demystify them for you.
Just when you get to grips with one picture resolution, better formats arrive. 4K Ultra HD is more common these days, having suceeded 1080p (Full HD) but 8K is now on the horizon, with some manufacturers already offering 8K TVs. It is a standard that refers to an even higher resolution that makes TVs sharper and more detailed still.
4K TVs come with a resolution of 3840 x 2160, so are capable of showing around four times the amount of pixels as a 1920 x 1080 Full HD set. 8K TVs boast a pixel resolution of 7680 x 4320, so another four times the amount of 4K and a total of 16 times the pixel count of a 1080p Full HD TV. That's super sharp indeed.
At present though, there are few sources of native 8K content. Most 8K TVs use intelligent upscaling technologies to make HD and 4K video look sharper, but without native 8K shows, films or games, there isn't much to watch on them that shows the extra crispness and detail afforded by such a high pixel count.
The refresh rate, which is generally 50Hz in the UK, 60Hz in the US, refers to how many frames are displayed on your TV in a second. 50Hz means than your TV screen refreshes 50 frames per second (fps) and therefore seems smooth and judder free.
Some formats use different frame rates, such as movies. Most films are shot in 24fps so Blu-ray playback invariably offers the same – ensuring that the action looks as the director intended. Videogaming though is better when displayed in as high a frame rate as possible, with action benefitting from more frames to keep it fast and smooth. Last-generation games consoles, such as the Xbox One and PS4, can reach 60Hz (60fps) although many games stick to 30fps for a more consistent picture.
The current-gen machines - PS5 and Xbox Series X/S - meet 60fps more often, although they are also capable of outputting 120 frames per second. That means a TV needs to be able to refresh at 120Hz to keep up.
Although the TV industry has largely settled on 4K and Ultra HD to describe the new, higher picture resolutions, you might also hear it referred to as 2160p.
That’s because a 4K pixel resolution is 3840 x 2160, while the picture shown is progressive, hence 2160p. “Progressive” describes the way images are refreshed on your screen. Each image is shown in its entirety with a progressive signal, while an interlaced signal means that only half the image is updated at a time. A progressively scanned image is therefore smoother and better than an interlaced one.
It is less common to refer to 8K video as 4320p, even though that's the vertical resolution.
ALLM (auto low latency mode)
This is a simple technology for gamers. An ALLM-enabled TV will automatically switch to a game-specific picture mode as soon as it detects gameplay. This often removes picture processing and improves latency, hence the name, "auto low latency mode".
Almost all TVs sold these days connect to the internet and commonly called Smart TVs. That means that they can download applications for different services, utilities or even games.
Different manufacturers use different operating systems on their TVs, but most offer the main apps for streaming services, such as BBC iPlayer, ITV Hub, Netflix, Disney+ and Amazon Video. Some offer 4K Ultra HD programming, HDR and surround sound audio.
Catch-up television is rapidly becoming more popular than conventional linear viewing or recording.
Rather than having to record a show, you can stream any programmes you missed directly through your connected Smart TV or set-top-box. All the major channels have their own catch-up service, but not all TVs give you access to all of them. If your TV has a Freeview Play badge (as detailed below), it is guaranteed to have catch-up services from the BBC, ITV, Channel 4, Channel 5 and UKTV Play's channels: Dave, Yesterday, Drama and Really.
Recording programmes is still available in many cases, but the ease of use and convenience of catch-up and on demand services makes them very compelling.
As well as conventional Dolby Digital stereo and surround sound, many of the latest TVs are compatible with Dolby Atmos.
Dolby Atmos is a sound format that, as well as the usual surround sound channels, adds height channels to make it seem audio is also coming from above you as well as around.
Many soundbars, AV receivers and speaker systems are compatible with Dolby Atmos. Some TVs even include upfiring Dolby Atmos speakers as part of their built-in sound system.
Dolby Vision/Dolby Vision IQ
We detail high dynamic range (HDR) picture technology below, and Dolby Vision is a specific HDR standard.
There are plenty of HDR TVs out there, far fewer that support Dolby Vision too. The latter tech is fractionally better although both are capable of showing a wider colour gamut and greater contrast between dark and bright areas. Dolby Vision TVs are renowned for their image quality with compatible content. Some Netflix and Disney+ 4K shows are capable of being shown in Dolby Vision, for example, as are many 4K Ultra HD Blu-rays.
Dolby Vision IQ is the same technology, but a TV sporting this badge will also be able to adjust the colour and contrast automatically based on the ambient lighting in your viewing room.
EPG stands for electronic programme guide. Most EPGs show you seven days worth of TV schedules but with Freeview Play, for example, you can also scroll seven days back to choose retrospective shows to play through catch-up.
Several TVs - especially premium ones - come with Filmmaker Mode. It is a setting that you can choose on your remote (or through the TV's menu) that will enact a number of preset picture options to make a movie look like "the director intended". It is backed by a number of different renowned film makers - hence the name.
Freeview Play is Freeview’s catch-up TV service in the UK and appears on a rapidly increasing number of televisions. It gives users the ability to catch-up with their favourite shows by scrolling backwards through the electronic programme guide.
By clicking on shows on the likes of BBC, ITV, Channel 4, Channel 5 and UKTV channels (which include Dave, Yesterday, Really and Drama), they open in each broadcaster’s respective app automatically, then play for you to enjoy. It makes catching up more simple.
Many TVs feature HDMI ARC or eARC on at least one of the HDMI ports. They each enable compatible soundbars or sound systems to automatically receive the correct audio signals when plugged into a HDMI ARC or eARC port, plus work seamlessly with things like the volume controls on your TV's remote without needing to be reprogrammed.
HDMI eARC is an enhanced version with extra bandwidth, which adds further features - such as the abiltity to stream uncompressed 7.1 audio from the TV to a soundbar, and high-res audio. It also has automatic lip-sync support to ensure both the TV pictures and audio output never go out of sync.
High dynamic range (HDR) picture tech allows a TV to show a wider colour range than conventional sets. They are also capable of greater brightness and/or deeper black levels. The end result is a more natural picture that can be bright and vibrant without losing definition or detail in darker areas.
4K Blu-rays have HDR encoding, so look great on a HDR TV. Many streaming services offer HDR on shows on their streaming platforms. Xbox and PlayStation consoles have HDR output for video and games these days.
There are several HDR standards - Dolby Vision, which is detailed above, HDR10, HDR10+ and HLG (see below). The difference between HDR10 and HDR10+ is that the latter is similar to Dolby Vision in that it changes the settings for colour gamut and contrast by each scene in a film or show, so is more accurate. HDR10 applies one setting for the entire video.
Another new standard, HDR10+ Adaptive is much like Dolby Vision IQ. It adjusts the overall HDR picture performance to also take into account the lighting in your room, thanks to a camera/sensor built into the TV.
Hybrid log gamma (HLG) is a form of HDR that most TVs now support. It is the HDR of choice for broadcasters, such as the BBC (through iPlayer) and Sky (through its Sky Q box).
LED refers to the backlight technology now adopted for the vast majority of LCD TVs. The backlight uses either side or rear-mounted LEDs to illuminate the LCD panel pixels.
Many TVs now have zonal backlighting, which allows for darker areas of a picture to remain as dark as possible because the backlight is only illuminating sections of the screen where needed rather than across the whole display.
Benefits to LED technology are very high brightness - especially on HDR LED TVs - and cheaper cost as they are easy to manufacture in bulk.
The biggest rival TV screen technology to emerge in recent times is OLED, which has a couple of major image benefits over rival tech. OLED pixels are self-illuminating, so an OLED TV does not need a backlight.
This makes OLED sets much thinner than their LED rivals. And black levels are much better as when an OLED pixel is off, no light whatsoever shines through it. There is also very little light bleed from pixel to pixel.
OLED TVs aren't as capable of the extreme brightness of some LED TVs, but more than make up for it in black levels and colour accuracy. They are generally more expensive.
Another reasonably new TV technology is MicroLED. Like OLED, each pixel in a MicroLED display is self-illuminating so has little or no light bleed from pixel to pixel. It is also therefore capable of extreme black levels and great colour accuracy.
However, as the pixels are made up of miniature LEDs rather than organic material, they can potentially shine brighter and are less prone to image retention. There are two main caveats to MicroLED technology though; first, due to the physical size of each pixel, full TVs are generally offered at huge screen sizes - the latest is 110-inches, for example; second, the tech is extremely expensive to manufacture. It is thought a fill MicroLED TV could cost more than $100,000.
As well as LED (as above) manufacturers have started to range Mini LED TVs. These are very similar - utilising backlights made up of many LED bulbs that illuminate in zones.
However, the difference is that the LEDs used in these latest sets are much smaller and therefore grouped in their thousands. This allows for much more accurate illumination, so the TV can have deeper black levels than before and look closer to the images available on an OLED TV.
Mini LED TVs are generally cheaper than OLED equivalents.
Like your mobile phone or tablet device, a modern TV will have a processing unit dedicated to ensuring apps and menus run smoothly. This will not be the same as the picture processing chips that have been used in TV manufacture for many years.
Therefore, it can sometimes be important to check the speed or quality of the internal processor, as that will determine how well your TV responds to your actions. Most TVs sport multi-core processors nowadays, much like premium smartphones.
VRR (variable refresh rate)
Some games consoles (Xbox Series X/S and Xbox One) offer support for variable refresh rate technology through the HDMI port. A VRR-enabled TV will therefore automatically match its screen refresh rate accordingly, depending on the frame rate being outputted by a game.
As many games have dynamic frame rates, or can suffer variable frame rates because of the graphical demands on screen, a TV without VRR can display stutter or tearing at times. This occurs when the game's frame rate fluctates and doesn't match the static refresh rate of the TV.
VRR adjusts this on the fly and so presents a smoother experience, without any noticeable artefacts.
Gaming PCs can be VRR-enabled too, while Sony plans to add support to the PlayStation 5.
Writing by Rik Henderson.