Ultra HD '4K' Blu-ray: Here's what we know

Ultra HD '4K' Blu-ray discs are due to hit the market at the end of 2015 with enhanced resolution, expanded color and more. Here's the 411 so far.


Updated: July, 2015

Ultra HD "4K" Blu-rays should be out by the end of 2015. Expect a handful of titles, and an even smaller handful of players. So essentially, just like every other format release in the past ever.

The possibility of pristine 4K content is exciting, but even more so is the potential for a wider color gamut, High Dynamic Range and more.

Here are the details as we know them. But one thing we know for sure: it's a disc! Round, plastic, shiny.

We'll also go out on a limb and assume the 4K BD players will all play standard Blu-ray discs and DVDs as well. I'm comfortable making this assumption based on the fact that the manufacturers involved aren't completely insane. It's doubtful the new discs will work at all in your current players, though it's possible (not in 4K though, obviously, see below).

There's also only one format! No UHDDVD or other such nonsense this time around. All the manufacturers are on board for a single unified format. Praise the video deities for small mercies.

Key specs

There are a lot of interesting specs. It's like the companies behind BD are throwing everything into 4KBD with either a "Yeah, let's do it right!" or "OMG streaming will kill us all!" mentality.

Higher frame-rates: 4K at 60 Hz. Not a big deal, honestly, as nearly all movies are 24fps (and will certainly will be in their native frame-rate on 4K BD) Still, some headroom for future concert videos or if people want to torture their brains with the HFR Hobbit. If anyone still cares about 3D, this is more than enough to do 4K 3D.

Expanded color: Thanks to advancements like quantum dots, a much wider color gamut is possible with 2015 TVs (and beyond). The problem is, they'll need expanded color gamut content for this feature to be useful. The format will have the ability to do a full Rec. 2020, though something similar to the DCI's P3 is more likely with most content. Either one is a big improvement over the current HD standard, Rec. 709, which dates back to the dark ages (of CRT). For more info, check out Ultra HD 4K TV color, part I and Part II.

High Dynamic Range: 4KBD will have HDR in the form of metadata, with Dolby Vision and other HDR formats as options. HDR is really cool. Part of this is an expansion of the bit-depth possible with 4KBD. Read more about it in High Dynamic Range arrives at CES 2015.

10-bit: Both HDR and expanded color are possible, thanks to a higher bit-depth of 10, greater than current HD's 8-bit. At the very least, this means more steps of gradation (no banding, not that Blu-ray had much).

H.265/HEVC: This is the latest codec, allowing 4K at "reasonable" bit rates. Technically, you could fit a 4K movie on a current BD disc (size-wise), but at that level of compression, what's the point? Instead, there will be...

Greater capacity discs: Most current Blu-rays are 25GB, some are 50GB. 4KBDs will be 66GB or 100GB. These multilayer discs (the 100 is a triple) will likely confuse your current player. That said, one layer for the old format, other layers for new, has been done in the past. Who knows if we'll see it here? (Probably not at launch, if ever.)

Audio: Expect Dolby Digital and True HD in their respective variations, and DTS in its various flavors, will all be there. We'll also see Dolby Atmos and DTS:X.

Should you care?

4K Blu-ray faces a lot of competition from 4K streaming.Photo by Netflix

The "blu" elephant in the room is whether anyone will actually care. Though BD disc sales are still a big source of revenue for the studios, their popularity is rapidly declining. Netflix and Amazon are both offering 4K streaming, Sony offers downloads, and that's certainly just the beginning.

The fact is, 4KBD will look significantly better than any streaming feed. The compression issues we've seen with HD are just as possible with UHD ( though how it's compressed is different).

Sadly, most people won't care. Worse, most people won't know there's a difference. 4K is 4K to most people (and if you're reading this, I'm not counting you in the "most" group). That's a battle not likely to be won by an archaic physical media, no matter how shiny it's marketed as being. Think that's pessimistic? How many of your friends still watch DVDs?

I've mentioned this before, but it's worth repeating: if a topic seems simple, and you need more than a sentence to explain why it's wrong, you're done. (I cribbed this from a Nate Silver idea about political scandals.)

So what happens is a large percentage of people will never even consider buying a 4KBD player, because to them, they can get the "same" 4K content from streaming.

Check out Stephen Shankland's article for more on the numbers of discs vs. streaming.

Will your current TV be able to take advantage of all this?


Partially, maybe. At the very least, it will need HDMI 2.0 and HDCP 2.2 to play the discs, and HDMI 2.0a to do HDR. The HDR and expanded color gamut modes likely won't work on pre-2015 TVs, and most of the time not even then.

Unless you just bought a TV, this is actually a good thing. 4KBD is a format for the future, unlike BD, which was more like the culmination of the tech of the past. So the fact that it's a little ahead of the game could be a good thing.

Or, it's also possible all the discs will be dumbed down to take advantage of older gear, which would be a bummer.

Even if the discs have all these new features (like color and HDR), and your TV can't make use of them, there will almost certainly be settings to make 4KBD work with your TV. Presuming it has HDCP 2.2, of course.

Bottom line

We should see Ultra HD BDs and BD players later this year. For picture-quality fans, this is great. The resolution will be awesome on really big TVs, and the potential color and HDR aspects will be amazing on any size TV (that can take advantage of it).

But it's never going to be as popular as Blu-ray -- we're too far into the streaming era for that. Hopefully it will tide us over until we all have ultrafast broadband and 4K streaming can actually look good.

Got a question for Geoff? First, check out all the other articles he's written on topics like why all HDMI cables are the same, LED LCD vs. OLED, why 4K TVs aren't worth it and more. Still have a question? Send him an email! He won't tell you what TV to buy, but he might use your letter in a future article. You can also send him a message on Twitter @TechWriterGeoff or Google+.