It took a few years to gain momentum, but 4K Ultra HD Blu-ray is now a firm fixture of virtually all major film releases.
The first 4K TVs went on sale back in 2012, but it wasn't until 2016 that the first 4K Blu-ray players from Samsung and Panasonic went on sale - alongside, thankfully, an increasing number of 4K Blu-ray discs. Today there are a number of 4K players on the market, you can pick up a 4K Blu-ray film in your local supermarket or online and, as streaming services step up to compete with 4K content, both are getting more affordable by the day.
So what is Ultra HD Blu-ray, how can you get it and how much does it all cost? Allow us to provide some answers...
What is the Ultra HD Blu-ray specification?
The preliminary spec for 4K discs was revealed at CES 2015, after which the Blu-ray Disc Association made the Ultra HD Blu-ray spec official (along with the name and the logo).
This format supports a resolution of 3840 x 2160, and while the specification is no guarantee that a film was actually shot and edited in 4K it does also offer additional technologies that improve picture quality such as higher frame rates of up to 60fps (frames per second) and high dynamic range (HDR). In physical media, HDR is currently delivered in three main formats: HDR10, HDR10+ and Dolby Vision HDR.
The majority of 4K discs come with the standard HDR10. What sets Dolby Vision and HDR10+ apart from HDR10 is the inclusion of dynamic metadata, a proprietary HDR technology that adapts its image frame-by-frame and, theoretically, renders each shot at its best. And what sets HDR10+ apart from Dolby Vision is its lack of licensing cost – TV manufacturers and content studios have to pay Dolby to use Dolby Vision and have little control over its development and implementation.
Initially, HDR10+ had only Amazon Prime Video promising supported content on its streaming site, and although Amazon remains the only major VOD service to offer it, more and more 4K discs in HDR10+ have made their way to market. Nevertheless, it's fair to say that Dolby Vision is comfortably the more widely available of the two formats.
4K Blu-rays are encoded using the High Efficiency Video Coding (HEVC) standard (also known as H.265), use 10-bit colour depth and can cover the full spectrum of the Rec.2020 colour space.
The discs themselves can be produced in three sizes: 50GB with support for an 82Mbit/s data rate, 66GB with 108Mbit/s and 100GB with 128Mbit/s.
What about Ultra HD Blu-ray audio?
The UHD Blu-ray specification also includes object-based immersive soundtracks such as Dolby Atmos and DTS:X. Some Blu-ray discs already support these formats, so it's not unique to UHD Blu-ray, but the next-gen audio soundtracks are more prevalent on Ultra HD Blu-ray discs.
So far Dolby Atmos has been the prevalent format on 4K disc releases, but DTS:X discs do exist. It's worth noting you won't find Atmos and DTS:X soundtracks on the same disc. It's one or the other.
What else does Ultra HD Blu-ray offer?
4K discs also support an optional digital bridge feature, allowing you to copy Ultra HD Blu-ray content to an external hard disk drive and portable devices such as smartphones and tablets.
The spec also mandates all Ultra HD Blu-ray players be able to play legacy Blu-ray discs. Sadly, 3D isn't featured in the Ultra HD Blu-ray spec – but with the majority of TV manufacturers having abandoned 3D ages ago, that's understandable.
OPINION: Here's why 4K Blu-ray is even better than 4K streaming
What Ultra HD Blu-ray players are on sale?
Current UHD Blu-ray players can be sorted into two categories: the under-£400 (affordable) models and the £600-and-above (high-end) players.
The Panasonic DP-UB9000 is the high-end Blu-ray player of choice these days (we're also big fans of the Pioneer UDP-LX500 and Oppo UDP-203, but both have now been discontinued), and it's a serious bit of kit that's worthy of its £900 ($1000, AU$1799) asking price, delivering a picture and sound performance that's well beyond that of its more affordable rivals.
Those more affordable models still offer an excellent performance, though, delivering quality that streaming services simply can't match. Our current favourites include the Sony UBP-X700 and Panasonic DP-UB820EB.
Other budget models from Panasonic and LG do exist, though new models are now released fairly infrequently. Moreover, Samsung dropped a bombshell in February 2019 by confirming it would end Blu-ray player production entirely.
On the games console front, Microsoft's Xbox One S was the first console to be compatible with 4K Blu-rays, though be warned, it's not quite up to scratch compared to rival standalone players.
The Xbox One X also incorporates a UHD Blu-ray disc player with native 4K, HDR and Dolby Atmos support. It’s pricier, has a more powerful processor to handle 4K gaming and, while dedicated players still win out, is an entertaining performer with 4K HDR discs.
The latest console from Microsoft, the Xbox Series X, also plays 4K Blu-rays but without Dolby Vision support despite the format being available via streaming apps (there'll be Dolby Vision games soon, too). That major disappointment, combined with its noisy disc drive, dents the Series X’s credentials as a 4K Blu-ray player – which is a shame because the picture performance is broadly good, with lots of detail, nicely judged colours and sharp edges.
As for the PS4 Pro and PS5? Surprisingly, Sony chose not to give the former the capability, focusing instead on 4K streaming. However, the PS5 does play 4K discs – though once again without Dolby Vision. While the picture is impressive in terms of deep blacks, drama, dynamism and colours it isn't really a match for even the most affordable dedicated 4K Blu-ray players when it comes to subtlety of shading and stability in motion.
What Ultra HD Blu-ray discs are on sale?
Ultra HD Blu-ray discs are now on sale worldwide, with major studios such as 20th Century Fox, Sony Pictures and Warner Bros all in on the action.
Disney joined the ranks in 2017 with Guardians of the Galaxy Vol. 2 as its first 4K disc release (and still one of our most-used test discs) before following up with Thor: Ragnarok in 2018.
The likes of Amazon, HMV and Zavvi all stock loads of Ultra HD Blu-ray releases, with the average price of a 4K disc around £20.
Will Ultra HD Blu-ray players play existing Blu-rays?
Yes, Ultra HD Blu-ray players are fully backwards-compatible with existing Blu-rays. Ultra HD Blu-ray discs won't play on old players, though, and you can't upgrade old decks, so you will need a 4K Blu-ray player in order to play 4K Blu-ray discs.
When it comes to regional restrictions, the good news is 4K Blu-ray discs have just one region code: worldwide. Essentially, they’re region-free. They can be played on any 4K player, in any part of the world.
However, your new UHD Blu-ray player will still have to observe the regional restrictions for DVDs and standard Blu-rays that continue to exist.
Most 4K Blu-ray discs come bundled with a standard Blu-ray version of the same film and those discs tend to be region-free as well. Search for the 'ABC' logo or read the fine print on the box, or look it up online to be sure – especially if you're thinking of importing the latest discs from outside your region.
However, it very much depends on the studio that owns the rights and the distribution of individual films as to whether a Blu-ray has region restrictions or not. We've noticed the major film studios (20th Century Fox, Sony and Warner Bros) have released their Blu-rays as region-free, but smaller studios are more likely to have restrictions.
What TV do you need for Ultra HD Blu-ray?
An Ultra HD Blu-ray player will work with pretty much any TV, but unless it's a 4K Ultra HD TV you won't see the disc's full-fat 4K resolution on screen. If your TV doesn't support it, the player will downscale the disc's content accordingly.
Any 4K TV should deliver a 4K picture, but only TVs with more recent specs will be able to take full advantage of what Ultra HD Blu-rays can offer. This includes HDR, which is one of the key factors for getting the best possible picture.
Most - if not all - 4K TVs on sale now support the standard HDR10 spec. When it comes to Dolby Vision and HDR10+, it depends on which manufacturer has backed which tech. LG and Sony are all in on Dolby Vision, with no HDR10+ TVs in their lineups, while Samsung is the opposite – all HDR10+ and no Dolby Vision.
Higher end models from Panasonic and Philips support Dolby Vision and HDR10+, which is great news for those who don't want to pick a side in this particular format war.
While 4K and HDR (or Dolby Vision) aren't necessarily linked technologies, if you're looking for a TV with one, it should ideally have the other in order to get the best picture performance.
Look also for a TV bearing the Ultra HD Premium logo - this means it meets certain 4K HDR standards, including support for standard HDR10. However, it doesn't mean the set necessarily supports Dolby Vision HDR.
Do you need a new AV receiver for Ultra HD Blu-ray?
Yes and no. If your system currently uses an AV receiver to do the HDMI switching, and carry audio/video over HDMI around your system, then this won't work with 4K Blu-ray unless your AV receiver is 4K-compatible.
The good news is most, if not all home cinema amplifiers in the market now are 4K compatible, including the excellent Denon AVR-X2700H and Sony STR-DN1080. Look for HDCP 2.2 and HDMI 2.0a (or HDMI 2.1) in the specifications for a clear indication of 4K compatibility.
Some higher end 4K Blu-ray players have two HDMI outputs so that video can be sent via one to the TV and audio can be sent to an AVR via the other. Alternatively, you can send video and audio from a 4K Blu-ray player straight to your TV and then have the audio sent from the TV to your AVR via optical cable or HDMI ARC.
Is Ultra HD Blu-ray worth it?
We certainly think so. It may be an increasingly niche market but 4K Blu-ray continues to impress us with its incredibly detailed picture quality, and better hardware and advances in HDR technology have improved performance even further.
Ron Martin, VP of Panasonic's Hollywood Lab and a crucial player in the development of Ultra HD Blu-ray, told What Hi-Fi? 4K discs will beat 4K streaming: "[a disc format] is the only repeatable, reliable way to do it. Streaming has certain advantages but many disadvantages."
We've compared how 4K streaming stacks up against 4K Blu-rays and standard full HD Blu-rays - and it's no surprise that 4K Blu-ray beats them all.
What about 8K Blu-ray?
You shouldn't hold your breath for 8K Blu-ray players or 8K Blu-ray discs. While 4K Blu-ray has proven fairly popular and will likely stick around for a long time to come, it's still a drop in the ocean compared to the popularity of streaming and we can't see a future in which any company is prepared to invest the huge sums of money into a new physical movie format when the war is so clearly already lost.
Given the inherent qualitative advantages of physical formats, that's certainly a shame, but with internet connections generally becoming exponentially faster with each year that passes, there's plenty of hope for higher quality movie streaming. Sony's new Bravia Core service, while not 8K, delivers streams in far higher quality than any service before it, potentially pointing the way to a future in which physical media isn't necessary in order to get the best picture and sound.
MORE:
The best 4K TV shows and films to watch right now
These are the best 4K Blu-ray discs to test your system
Check out our round-up of the best TVs you can buy right now
Get the sound right with one of the best AV receivers
Finally, here are the best 4K Blu-ray players
