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Author Topic: Why 4K video, and which 4K, 3820 or 4096  (Read 4815 times)

EinstStein

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Why 4K video, and which 4K, 3820 or 4096
« on: May 15, 2016, 01:20:10 PM »

I don't have a 4K TV or monitor yet, but the video I make today is better to be compaible with future's TV or monitor. I assume it can be converted through over sampling or simply shoot 4K now.

However, I still cannot see the difference of 4K video as of today.  Anyone can really see that? May be because the programs are not from 4K cameras?

I can simply buy a digital camera with 4K video, but then another quesion comes, there are two types of resolution both claimd to be 4K, the 4096 DCI and 3840 UHD. How do you choose?
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smthopr

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #1 on: May 15, 2016, 02:27:33 PM »

I don't have a 4K TV or monitor yet, but the video I make today is better to be compaible with future's TV or monitor. I assume it can be converted through over sampling or simply shoot 4K now.

However, I still cannot see the difference of 4K video as of today.  Anyone can really see that? May be because the programs are not from 4K cameras?

I can simply buy a digital camera with 4K video, but then another quesion comes, there are two types of resolution both claimd to be 4K, the 4096 DCI and 3840 UHD. How do you choose?

I've been working in 2k, 2048x858 pixels for DCI/theatrical distribution.  For the TV version, I start by cropping the 2048 to 1920 pixels so that there is no scaling involved.  Usually this works well.  Some shots require the full 2048 pixel width and are scaled down to 1920 pixels.

I would work in a similar fashion in 4k, assuming that there will be a theatrical presentation of the film and shoot 4096 pixels and crop to 3840 for TV for most shots.

Your challenge might be that inexpensive (relatively speaking) "4k" cameras will only shoot 3840 UHD...
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Don Blauvelt

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #2 on: May 15, 2016, 03:09:24 PM »

If you can afford it, going with 4K DCI 4096 X 2160 is never having to say your sorry, because you can always go to 4K UHD 3840 X 2160 from those files. Just keep in mind the 3840 X 2160 will have a slightly different crop.

I just purchased a camera that records only in DCI 4096 X 2160, but I won't have any actual experience shooting and editing it for a while. When I do I'll post info here.
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John Brawley

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #3 on: May 16, 2016, 07:03:57 AM »

I don't have a 4K TV or monitor yet, but the video I make today is better to be compaible with future's TV or monitor. I assume it can be converted through over sampling or simply shoot 4K now.

However, I still cannot see the difference of 4K video as of today.  Anyone can really see that? May be because the programs are not from 4K cameras?

I can simply buy a digital camera with 4K video, but then another quesion comes, there are two types of resolution both claimd to be 4K, the 4096 DCI and 3840 UHD. How do you choose?


There are two 4K numbers, and you've identified both of them.

One comes from TELEVISION, and that's the 3840.

It really comes down to aspect ratios.  TV is 1:1.78 (16x9) , whereas cinema is 1:1.85 or 1:2.35

soooo.

3860 is the 1.78 ratio for TV or sometimes called UHD.

4096 is the CINEMA standard, allowing for 1:1.85 (it's actually 1.89 but they allow some wriggle room for masking in the cinema)

I wouldn't get too hung up on the numbers.  Some people worry about their UHD camera not being a 4K camera, but it's kind of stupid.  Most people don't realise that the currently most acclaimed high end cinema camera which shot most of the cinematography oscar winning film Revenant is a 2.7K or maybe 3.2K sensor (the Arri Alexa)

It's moronic but Netflix when commissioning shows are saying it has to be a 4K camera, so that actually means the digital cinema camera that has pretty much been the gold standard for CINEMA PROJECTION isn't considered good enough for a low data rate streaming service on a home Television.

It's total mesuarbating of the worst kind.  So many things other than pixel resolution affect the end result.

So to answer your question directly, is your 4K TV a 16x9 TV ?  If so then you're fine with UHD which will fill it nicely.  If you shoot 4096 then you're going to have to scale it (and have a black bar at the top and bottom ) or you'll have to crop it to...ummmmm UHD.....

Don't get too hung up on it.

JB

 
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smthopr

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #4 on: May 16, 2016, 11:30:40 AM »


There are two 4K numbers, and you've identified both of them.

One comes from TELEVISION, and that's the 3840.

It really comes down to aspect ratios.  TV is 1:1.78 (16x9) , whereas cinema is 1:1.85 or 1:2.35

soooo.

3860 is the 1.78 ratio for TV or sometimes called UHD.

4096 is the CINEMA standard, allowing for 1:1.85 (it's actually 1.89 but they allow some wriggle room for masking in the cinema)

I wouldn't get too hung up on the numbers.  Some people worry about their UHD camera not being a 4K camera, but it's kind of stupid.  Most people don't realise that the currently most acclaimed high end cinema camera which shot most of the cinematography oscar winning film Revenant is a 2.7K or maybe 3.2K sensor (the Arri Alexa)

It's moronic but Netflix when commissioning shows are saying it has to be a 4K camera, so that actually means the digital cinema camera that has pretty much been the gold standard for CINEMA PROJECTION isn't considered good enough for a low data rate streaming service on a home Television.

It's total mesuarbating of the worst kind.  So many things other than pixel resolution affect the end result.

So to answer your question directly, is your 4K TV a 16x9 TV ?  If so then you're fine with UHD which will fill it nicely.  If you shoot 4096 then you're going to have to scale it (and have a black bar at the top and bottom ) or you'll have to crop it to...ummmmm UHD.....

Don't get too hung up on it.

JB

Please also note that 4K, for Flat (1.85:1) presentation is 3996Ũ2160 pixels for cinema projection.  Just to make things more complicated for really no good reason...
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EinstStein

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #5 on: May 16, 2016, 10:04:45 PM »

I don't care the exact number of pixel. I am fine with even 2K.
But I am considering the future compatibility.

From what I studies so far, what important to me is the future's professional movie, which apparently would be DCI.
The UHD seems works fine with the current (old) movie or home made movies (from cheaper camera).

My conclusion is, I will wait a little while. There is no need to jump into UHD yet, either UHD will be upgraded ti DCI or 4K is not important at all.

 





There are two 4K numbers, and you've identified both of them.

One comes from TELEVISION, and that's the 3840.

It really comes down to aspect ratios.  TV is 1:1.78 (16x9) , whereas cinema is 1:1.85 or 1:2.35

soooo.

3860 is the 1.78 ratio for TV or sometimes called UHD.

4096 is the CINEMA standard, allowing for 1:1.85 (it's actually 1.89 but they allow some wriggle room for masking in the cinema)

I wouldn't get too hung up on the numbers.  Some people worry about their UHD camera not being a 4K camera, but it's kind of stupid.  Most people don't realise that the currently most acclaimed high end cinema camera which shot most of the cinematography oscar winning film Revenant is a 2.7K or maybe 3.2K sensor (the Arri Alexa)

It's moronic but Netflix when commissioning shows are saying it has to be a 4K camera, so that actually means the digital cinema camera that has pretty much been the gold standard for CINEMA PROJECTION isn't considered good enough for a low data rate streaming service on a home Television.

It's total mesuarbating of the worst kind.  So many things other than pixel resolution affect the end result.

So to answer your question directly, is your 4K TV a 16x9 TV ?  If so then you're fine with UHD which will fill it nicely.  If you shoot 4096 then you're going to have to scale it (and have a black bar at the top and bottom ) or you'll have to crop it to...ummmmm UHD.....

Don't get too hung up on it.

JB
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Hywel

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #6 on: May 17, 2016, 10:44:00 AM »

Shoot in 4K UHD, down-sample to full HD for delivery :)

That gives you something like the full 4:4:4 colour space and 10-bit range, plus nice detail with very little Moire or aliasing because of the magic of oversampling. The exact 2:1 downsample is easy on the processing power and gives very good results.

Obviously if you're intending your films for cinema projection, you'll be better off shooting 4K (cinema version) in either 1:1.85 or 1:2.35.

But for most of us mere mortals, delivery in 16:9 full HD is a good compromise for most uses, unless you want the 'scope 1:2.35 ratio for visual effect.

If you're really delivering in 4K, shoot in 6K+ and downsample, likewise.

Cheers, Hywel
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EinstStein

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #7 on: May 17, 2016, 10:34:21 PM »

Again, the difference due to that few pixels is hardly matter to me in terms of image quality.
I am looking for the insurance of future compatibility and flexibility.




Shoot in 4K UHD, down-sample to full HD for delivery :)

That gives you something like the full 4:4:4 colour space and 10-bit range, plus nice detail with very little Moire or aliasing because of the magic of oversampling. The exact 2:1 downsample is easy on the processing power and gives very good results.

Obviously if you're intending your films for cinema projection, you'll be better off shooting 4K (cinema version) in either 1:1.85 or 1:2.35.

But for most of us mere mortals, delivery in 16:9 full HD is a good compromise for most uses, unless you want the 'scope 1:2.35 ratio for visual effect.

If you're really delivering in 4K, shoot in 6K+ and downsample, likewise.

Cheers, Hywel
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lowep

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #8 on: May 19, 2016, 10:47:29 PM »

Hey Cooter hard to believe you donīt do 4K?

I traded my Sony EX1 in for an X70 mostly for the in-built 4:2:2 but also used "future proofing" as an excuse to change toys, even if at the time when I got it the X70 did 4K like Donald does politics. Fortunately since then Sony has upgraded the X70 to 100Mbs and what I am finding to be the best thing about the 4K sensor is that it does give a nice extra kick when recording in regular 1080p HD that is not a bad thing

... though still not sure if I did the right thing to trade in my big ugly EX1 (lovely lens) for the compact X70: time will tell.
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Morgan_Moore

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #9 on: May 24, 2016, 04:02:14 AM »

4k is 17:9 UHD and HD are 16:9

It would seem that the most 'archival' is to shoot 17:9 with frame guides on the monitor to ensure that all 'critical image' (text for example) is inside the 16:9 box.

S
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fredjeang2

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #10 on: July 27, 2016, 11:15:53 AM »

Hey Cooter hard to believe you donīt do 4K?

I traded my Sony EX1 in for an X70 mostly for the in-built 4:2:2 but also used "future proofing" as an excuse to change toys, even if at the time when I got it the X70 did 4K like Donald does politics. Fortunately since then Sony has upgraded the X70 to 100Mbs and what I am finding to be the best thing about the 4K sensor is that it does give a nice extra kick when recording in regular 1080p HD that is not a bad thing

... though still not sure if I did the right thing to trade in my big ugly EX1 (lovely lens) for the compact X70: time will tell.

Cooter does not do 4k?

razrblck

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #11 on: July 27, 2016, 12:32:31 PM »

Cooter does not do 4k?


Nope. I believe he has a RED (or a couple) like the EPIC and Scarlet but with the old sensors so below 4K resolution. He also works with a Sony a7 and possibly some Canon gear from what I remember. Considering what he does, 4K would probably slow his workflow too much for resolution he doesn't need.
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fredjeang2

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #12 on: July 28, 2016, 05:29:00 AM »

It makes sense.
If my memory is correct I think in another thread
It has even been established that upsampling R1 up to
4k does not ruin the quality and almost not noticiable
For the common of mortals.
(Fact that I also noticed with BMC footage)

razrblck

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #13 on: July 28, 2016, 06:43:29 AM »

Yes, as much as we want to have perfect pictures, people (myself included) are a lot more bothered by bad audio than upsampled video.
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bcooter

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #14 on: July 28, 2016, 04:04:52 PM »

It makes sense.
If my memory is correct I think in another thread
It has even been established that upsampling R1 up to
4k does not ruin the quality and almost not noticiable
For the common of mortals.
(Fact that I also noticed with BMC footage)


No we shoot 4k.  Have two RED One's MX one Scarlet MX and a Sony A7s (which will be replaced).

The R1's are 4.5K (2.4:1), 4K (16:9) the Scarlet 4K (Full Frame, 2.4:1, 16:9)  At least that's what RED says.
 
The A7s II is 3840 x 2160 (uhd in 16:9).

As John B says most of the movies you see are shot on 2.7 to 3.2 Arri's that are projected 4k and I don't think anyone notices or cares but if a client or producer wants 4k, they get 4k and as everyone knows Arri's are very robust cameras.

This is a very interesting talk from John Seale on the shooting of fury road.   It's a long listen but will tell you a lot about camera selection, reasons and issues.

It won't embed here but if you hit the link it will play in a new window.





IMO

BC




« Last Edit: July 28, 2016, 08:03:22 PM by bcooter »
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razrblck

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #15 on: July 29, 2016, 05:22:34 AM »

Thanks for the video, I've been looking for some more technical BTS on Fury Road for quite some time.
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fredjeang2

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #16 on: July 29, 2016, 07:33:44 AM »

LuLa should implement a like button with prizes.
Above a certain number of likes we win a 4k camera.
Below a certain number of likes, we have to pay 2 euros penalty to the site,
Wich is the way to financiate the prizes.

(Sounds a bit like Trump engineering....)

razrblck

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Re: Why 4K video, and which 4K, 3820 or 4096
« Reply #17 on: July 29, 2016, 10:25:53 AM »

I'll be fine even with a 2.7K Alexa. :P
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