planning for 4K equipment (from camera to display)

[Piotr Wozniacki]

As some of you you might know, I'm going to use an UHDTV rather than a 4k PC monitor for my edit monitoring purposes - just as I've used my 50" Panasonic FHD plasma with my 1080p editing. The main reason is that my editing studio must serve other purposes as well (such as continue being my Home Cinema, with all the audio high-end equipment already in place and lack of another room in my small house to accommodate it); also I spend much, much more time doing my other, main profession-related things (CAE), as well as simply running my home office, than I do editing video in Vegas - hence the need for my desk to accommodate 2 computers instead of one, which doesn't leave much (if any) free space for yet another monitor... All in all, the display must end up hanging on the wall rather than standing on the overcrowded desktop - and as to display color/levels calibration, I can assure you that with e.g.the middle-class Panasonic Viera TX-50AX800E I can do it no worse than on one of those entry level 4K monitors...

Anyway, I have one more, extremely important to me, question to those more knowledgeable than myself: we all know that even with the regular HDMI 1.4, displaying 4K from a computer *IS* possible - just with the refresh rates limited to 30/25/24 Hz (depending where we live). Please help me understand the relation between this limited refresh rate (which would probably make the Windows desktop a mess, difficult to work with due to flickering, illegible fonts etc.) on the one hand, and the fps speed of movies displayed this way on the other... Since I will most probably limit myself to a 24/25/30 fps camera (the 50/60p ones being another, more expensive league) - is the abovementioned limitation of HDMI 1.4 most cheaper UHDTVs are still equipped with a real problem? The Viera TX-50AX800E I mentioned is *NOT* limited like this - it offers a single HDMI 2.x plus DisplayPort, so I'd be covered for up to 4k@50/60p. But this model is not cheap - so do I really need those inputs if my camera - most probably just the AX100, *maybe* X70 - won't be capable of 4K@50/60p, anyway? Of course, the main Windows desktop would go to a regular desktop monitor with the mediocre resolution of 1680x1050, with only movies and my Vegas previews displayed on the UHDTV...

I'm asking this very important question as I have no idea how a 50" *non-plasma* flat screen "feels" at 24/25/30 Hz refresh, and it's not easy at all to "test-drive" one as most shops have the highest possible demo content permanently connected to their UHD Bravias or Vieras... My only personal experience is with plasmas: at a refresh rate as low as 25 Hz they all flicker like crazy; heck - even the nominal 50 Hz (in EU - in the US it would be 60 Hz) is too low, so before plasmas were discontinued even by Panasonic, they actually used refresh rates being integer multiples of that (like 100 Hz and up in EU, or 120Hz and up in the US). So with a plasma, this would be a no-brainer - just like, of course, with *any* display type displaying content from a *4K camera capable of 50/60p*... But I have *no* experience whatsoever re: 4k playback of 24/25/30 fps material at such a low refresh rate on *LED displays* (and there are many LED flavors to further complicate the picture - pun intended :)).

Of course one might say: forget the entry level stuff and go for at least the medium-level, if only for it to be future proof enough. But I'm very much on a tight budget, hence it's not that simple a decision for me - please help me to make a right one! TIA,

Piotr

PS. Oh, and please don't try to talk me into a monitor instead of UHDTV - I have reasons important enough for having already made my mind on the latter.

[Andy Wason]

Hi Piotr, I use a 65" seiki LED 4K tv running at 3840x2160 at 30Hz on a cheap nvidia zotac GT730 video card.
Like you, I used a panasonic plasma for 1080p editing previously.
I use this setup for photoshop, premiere cc etc. and am very happy with it. Text is fine and downloaded 4 k videos run fine also. I love the amount of info you get on the screen and I get to see my photoshop images much more clearly than a 1080p monitor.
This is a pretty cheap setup so it certainly won't be broadcast standard, but it works fine for me.
Andy

[Piotr Wozniacki]

Hi Andy; how do you connect your computer to the Seiko? If it is HDMI - which version? And if version 1.4 - doesn't the flicker bother you?

Thanks,

Piotr

[Andy Wason]

Hi Piotr, I don't shoot or edit any 4k material, but I play back a lot of 1080p movies on my computer at 30Hz and i don't see a problem. Remember the 30Hz is progressive whereas most tv channels are 60i.
Most movies are shot at 24 frames per second which is essentially progressive.

I viewed some 4k youtube videos (I looked for some with lots of movement rather than the DSLR time lapse videos) and they look fine to me. I'm not sure which variant of HDMI I have, i just plugged in any old HDMI cable and it works.
Andy

[Ron Evans]

NTSC TV's normally refresh at 60hz or the newer ones at 120 hz or more. If the input is 30P the TV will still refresh at 60hz or more and just repeat frames to match the refresh rate. For 24P it will use 3:2 pulldown cadence to match the frames to the refresh rate. Newer TV's that refresh at 120Hz or more can sometimes correctly display 24P much like a multiblade shutter on a film projector so 120Hz would be like having a 5 blade shutter on a film projector. If the TV is 60hz only then 24P will have a pulldown cadence not true 24P.

Ron Evans

[Ricky Sharp]

Some displays (e.g. my plasma) offer a 72Hz mode to display 24p material without pulldown.

[Ron Evans]

Originally Posted by Ricky Sharp

Some displays (e.g. my plasma) offer a 72Hz mode to display 24p material without pulldown.

Yes I forgot about some of the plasma TV's equivalent to a 3 blade film projector.

Ron Evans

[Piotr Wozniacki]

Hi Ron,

Yes - flat display (HD)TVs have been offering - as I put it in my post - refresh rates much higher than the basic 50/60 Hz (depending on whether in PAL or NTSC area), and those refresh rates are integer multiplies of the basic frequency. My 1080p Panasonic plasma I've been using for several years only offered 2x 50 Hz = 100 Hz, but even this has been enough to get rid of any flickering, which (at 50 Hz, not to mention 25 Hz) can be very annoying - especially on plasma displays (much less so on LCD/LED displays).

Now - coming back to my original question in this thread - I'd like to use a LED 4k UHDTV, and unless it has HDMI 2.0 or DisplayPort (very rare, the latter) it would switch to 25 Hz if I played my 25fps 4K content on this. Using DisplayPort or HDMI 2.0 I reckon (though please somebody confirm) it would stay at 50 Hz (which would create an analogical situation to the way I displayed my 50p, or ever 25p, 1080p material with my 1080p plasma refreshing at 100 Hz: each frame would technically be displayed twice (with 50p) oraz 4 times (with 25p) - a very nice, stable and fluent, way of watching HD contents. So back to 4K and UHDTV (and not plasma as none exist, but LED) - with HDMI 2.0 or DisplayPort my 25p 4K material should be played back with every single frame displayed twice! This should look very nice - but can anyone confirm that? Of course, should my 4K camera be able of producing 4K at 50 fps, each frame would be displayed just once - but with LED displays much less prone to flickering than plasmas, this should work and look nice, too...

Now - let's consider a situation where due to not enough cash, I can only purchase an entry-level UHDTV LED display without DisplaPort, and with HDMI 1.4 - only capable of 3840x2160 @ 25 Hz. Would the display be flickering when displaying 4K at 25 fps (like that from AX100 or X70)?

And finally: what would happen if I decided to go with a 4K camcorder capable of 50/60 fps, but connected my PC to such a low-refresh UHDTV only capable of 4K@25Hz (like all those entry-level ones offering only HDMI 1.4 and no DisplaPort connections)? Just what happens then?

The 2 above questions are just re-wording of my OP in this thread that somehow nobody answered, so I thought it was my poor English; are they more easily understood now?

Piotr

[Jack Zhang]

It is far to early to be adopting 4K. Currently all 4K displays are Rec.709. We need to wait until Rec.2020 becomes standard.

HDMI 2.0 already fails one part of Rec.2020. It can only deliver 8bit 4:2:0 4K at 60p on HDCP 2.2 protected sources. So all this talk of high dynamic range pictures would be meaningless without 10bit delivery to the display. ALL consumer content has to be protected, so it helps no one when HDCP needs a ton of bandwidth which prevents 10bit 4:2:2, which is likely required for high dynamic range video.

[Piotr Wozniacki]

Absolutely agree, Jack. However - even though I do consider cameras capable of 50/60 fps (like Z100, for one) - they still only deliver 4k with 4:2:0 color so I wouldn't be losing much in terms of color space (BTW if Iwas to follow full 4K standard spec so strictly, I'd never think of monitoring on a UHDTV but a specialized monitor...

[Ricky Sharp]

If you're tight on budget, wouldn't it make sense to keep your existing HD workflows longer? Otherwise, you're risking spending money now on 4K that I don't think you'd ultimately be happy with. And you'd then be spending more on 4K when equipment exists that is up to the specs.

[Piotr Wozniacki]

Strange that - apart from various (soome good, others not so good) pieces of advice - nobody offers a straight answer to my question. Hm...

[Andy Wason]

Well... considering the two question marks in your OP weren't really questions at all, I thought I did a pretty good job of answering what I thought your questions were!

[Piotr Wozniacki]

Andy - I realize I was trying to answer my own questions while typing them, but believe me - they were real questions, bro...

My main problem is that in Poland, it's not that easy to find a well-supplied shop and try out every combination of equipment one is interested in. What I know for sure is limited to HD (1080p) and plasmas as display devices (as opposed to 4k and LEDs), as I have been editing my HD stuff using a Panasonic 50" plasma this way for several years with great results; as to whether the trick to make a HDMI 1.4-only UHDTV work with 4K content by limiting its refresh is a mystery to me - all I know people do it, but I'm sure it's far from being "professional"... How far? I've no idea (and I'm not even touching the intricacies of screen calibration, color space and depth, or alike here), as on the one hand LED displays are not as flicker-prone as plasmas, but on the other I can only guess a higher fps material (50/50 fps) cannot be played back this way at all...Or can they?

So yes, they are real questions - and I'm still hoping for some answers. Being on the budget I just cannot afford to use the "brute force" method: if in doubt, choose the best stuff money can buy:)

[Piotr Wozniacki]

Oh, and one more thing: I'm totally aware that in my plans of selling the rig mentioned in my sig, and going for a currently available 4K camera (and not an FS7, either) - I'm choosing a much less "professional" solution for what can only be called "consumer" (not even "prosumer"). But I'm doing it for a reason, so please to not bash me for it :)

Piotr