4k hdr tv, talk to me...

Lodious · September 2016

It's all totally irrelevant to most people, as the setup of TV will make far more difference to the image quality than HDR / 4K / whatever.

ThePrettyDamned · September 2016

I'll wait till 5k/whTever is next.

Then I'll spend 300 quid on a 4k telly

Sporky · September 2016

ThePrettyDamned said:

I'll wait till 5k/whTever is next.

8K is probably next.

Lord knows how they're going to get it down wires.

strumjoughlamps · September 2016

Sporky said:

Lord knows how they're going to get it down wires.

Rocker · September 2016

@Sporky, did I read that you are suggesting that some TVs need better cables. What on earth put that idea into your head?

chrispy108 · September 2016

Maybe the University degree and the years of industry experience, alongside the facts and the specifications of the new higher resolutions. 4 times the data means you need a better cable.

Note, better doesn't mean a nicer colour or has a wooden bit on it.

ThePrettyDamned · September 2016

Rocker said:

@Sporky, did I read that you are suggesting that some TVs need better cables. What on earth put that idea into your head?

It's a digital communication, not analogue.

Like hdmi - do you know what version we are up to now?

Basically, as our needs evolve (lol "needs") technology needs to keep up. I've been looking at motherboards with the latest USB and hdmi format, both of which are capable of transferring more data faster - which is important if you're effectively streaming 24 8mp photos every second along with sound and other information along with it.

Computers are only just keeping up - not many people game at 4k.

Sporky · September 2016

Rocker said:

@Sporky, did I read that you are suggesting that some TVs need better cables. What on earth put that idea into your head?

Why are you still drowning kittens, Rocker? You should read what people post, not what your superstitions tell you.

Original HDMI cables came as standard or high speed; this denoted the bandwidth they could sustain at a bit error rate of 10^-9 - the maximum permissible in the HDMI specification. The theory was that standard cables were good for 720p (which has a data rate of 2.23Gbps), and high speed cables were good for 1080p60 (which has, unsurprisingly I hope, a data rate of 4.46Gbps), though in practice it was possible to build a 1080p60 capable cable that only met the standard specification.

Still with me? Good.

As any fule kno, 4k/UHD requires a LOT more bandwidth than HD. UHD60 with 4:2:0 subsampling and 10-bit colour knocks in at 11.14Gbps. That, clearly, will not go through a cable that can only support 2.23Gbps. Full-fat 4k - 4096x2160 at 60 frames per second, no subsampling and 12-bit colour, needs a whopping 26.73Gbps.

To give you a rough idea, you can meet the standard cable spec with 28AWG conductors and an overall foil shield. A current spec High Speed cable needs 24AWG conductors as a minimum, interleaved shielding, careful dielectric selection and so on.

Let's be clear though; even a boggo HDMI 1.0 standard speed cable is carrying somewhere around 10,000 times the bandwidth needed for an analogue audio interconnect. Five orders of magnitude. For comparison that's about the same as the difference between the height of a table and where a jumbo jet flies.

I know you're just trolling, but I would dearly like to think you're willing to open your mind and read some of this - maybe even try to understand it, and to understand why different cables have different requirements, and that these requirements are all very, very well understood by the engineering profession.

chrispy108 · September 2016

strumjoughlamps said:

Sporky said:

4K yes, but with HDR?

do you think HDR will take off? apparently the Beeb are already on bored with the tech yet it took 3 years to jump on the 4k wagon..

Like the Beeb were early adopters of 3D which they don't do any of now?

Bidley · September 2016

ThePrettyDamned said:

I'll wait till 5k/whTever is next.

Then I'll spend 300 quid on a 4k telly

My 4k TV was £399

Sporky · September 2016

Axe_meister said:

To me HDR is far more impressive than 4K. Compare an HDR picture at 1080p with a 4K without and then a 4K with HDR. 4k with HDR is only marginally better but HDR at 1080p to me looks far better than 4K without.

Sorry, missed this one. Your experience is normal - HDR is more noticeable than deep colour or higher resolutions for most people.

Axe_meister said:

A pity broadcasters and movie companies are not pushing 48fps. You get a sharper picture without the need for high resolution

Not so sure on that one. I've seen some test material; 48fps looks sharper, certainly, but to me (and I'm not alone in this) it doesn't look 'right' for films. Partly that's down to what we're used to, but if you see the relatively raw camera output at higher frame rates it looks like telly, not like cinema.

Rocker · September 2016

@Sporky, not trolling. Always willing to learn something new. Virtually everything you wrote is way over my head. But I accept what you said, why should I wish to do otherwise? If you could suggest a beginners guide, it would be much appreciated.

Sporky · September 2016

In simple terms, more pixels means more bandwidth.

From HD ready to full HD is double the pixels and double the bandwidth.

From full HD to 4kUHD is four times the bandwidth (gross simplification).

The bandwidth for HD ready is 10,000 times higher than the bandwidth of analogue audio. Analogue audio might as well be DC by comparison.

Try this - http://www.extron.com/download/dltrack.aspx?file=Digital_Design_Guide_3rd_edtn_RevE.pdf&id=78184

Axe_meister · September 2016

Just use CAT 7 or CAT8 Ethernet

Chalky · September 2016

@Sporky, where do I buy such a nice cable for my 4k HDR TV? Can you recommend a particular cable and seller?

Sporky · September 2016

Maximum bandwidth for CAT7 is approx 10Gbps - not enough for 4K60 without colour subsampling. What's CAT8 do?

Axe_meister · September 2016

Cat8 is for 40Gps switches which are now entering data centres.

Axe_meister · September 2016

Or we switch over to fibre channel

Sporky · September 2016

40Gbps would last us a while, but I think in five years we're going to see anything over about 3m be done in fibre - there are already HDMI cables that are fibre in the middle (though the current ones have their limitations). Fibre is a mature technology.

Chalky said:

@Sporky, where do I buy such a nice cable for my 4k HDR TV? Can you recommend a particular cable and seller?

My employer does some very good ones, but a 3.6m one is about £75 inc VAT. In a commercial installation it makes sense (a revisit to replace a dodgy cable will cost far more than that), but for home use it's probably/definitely over the top.

I'd suggest just buying something that's rated HDMI2.0 High Speed. For example (I've not used one as I get all my HDMI cables as part of a demo pool) this, based on the specs and my experience with other cable types in the range, should do nicely for £5.49 for 3m:

https://www.amazon.co.uk/gp/product/B014I8T0YQ/ref=amb_link_209467027_9?pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=hero-quick-promo&pf_rd_r=W0SMAEQH532M2WNSTW9V&pf_rd_t=201&pf_rd_p=866904207&pf_rd_i=B003L1ZYYM

Certainly don't spend silly money on any cable that claims better performance (such as deeper blacks, more vibrant colours, blah blah). To be sold as HDMI2.0 and High Speed it must meet the performance standard. Exceeding the standard has no benefit.

sweepy · September 2016

I use my 43" LG 4K tv as a monitor for my MacBook Pro, works flawlessly

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4k hdr tv, talk to me...

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