Gh4 1080p or 4k

[Darrell Varga]

Greetings:

With the new Gh4, what would be the best configuration:
-Record to internal cards: 4k 4.2.0 8bit
-Record to external Atomos Ninja Star via hdmi: 1080p 4.2.2 10bit

Is it better to forgo the 4k for the sake of the broadcast standard 4.2.2 color?

It looks like the Atomos Shogun is the only recorder that is 4k. I was hoping for something that would keep the rig small. Ont he other hand, recording to HDD is very cost efficient.

I don't like the look or cost of the YAGH brick. The new Ninja Star (to ship in May) is quite compact, good for one-man band documentary shooting.

The new Panasonic U3 internal cards are quite expensive. The CFast cards for the Ninja Star are also expensive but an adapter is available to use the recorder with SD cards.

The micro-HDMI is also a concern, but I think a locking device could be rigged to ensure that it remains connected.

I would appreciate hearing comments on these configurations.

[Bob Richardson]

(Sorry if this is a duplicate reply, the server appears to have eaten my first one after a timeout.)

It appears that people have figured out a way that the 4K footage recorded in-camera in the GH4 can be reduced to 1080P while sampling all the pixels, getting you true 10bit 444 2K footage for editing. So if your target output is 1080P, this might get you all the advantages you need without having to buy an expensive base or an external recorder. If it's true and a quick workflow can be established.

[Gary Huff]

Not going to get 10-bit from the 8-bit source. At best it will help cover up any banding. Anything remotely associated with EOSHD needs to be taken with a huge grain of salt.

Best option is to shoot 10-bit 4:2:2 1080 from the HDMI, and then use the Atomos Shogun for 10-bit 4:2:2 4K in the later portion of the year.

TANSTAAFL.

[Andrew Dean]

in our quicky shootout test, the 1080 gh4 had much more noise and less detail than the 4k downsampled in post. Dunno if that was a preproduction issue or not.

[Noa Put]

You don't have access to the camera anymore Andrew? That would be important to know if it is either a operator error or a camera "bug", otoh, one might just shoot 4k all the time so you'd have more options in post and a better looking 1080p, like a sharper image and if it appears to be a camera limitation, less noise.

I read somewhere that shooting in 4k and then downsizing it to 1080p makes the noise smaller so it might appear less noisy but the noise also has been reduced in size by a factor of 4, not sure if this makes any sense?

[Phil Goetz]

What about the output of the YAGH over SDI? I assume it can do 1080 out. I know there are 4 SDIs but those can be combined for 4k. I am wondering even with the camera set to 1080. Not doing 4k internal at the same time.

[Gary Huff]

Originally Posted by Phil Goetz

What about the output of the YAGH over SDI? I assume it can do 1080 out. I know there are 4 SDIs but those can be combined for 4k. I am wondering even with the camera set to 1080. Not doing 4k internal at the same time.

They are actually 4 3G-SDIs (confirmed by Mitch Gross) so you can get 4K out of only two 3G-SDI connections.

Yes, it can do 1080 out. I set it to 4K myself and use 1080 out of the HDMI port externally for the Star all the time. It's actually the best looking native 1080 the GH4 can produce.

[Patrick Jenner]

It depends, what you need. In native 1080P mode the camera has a fair bit of aliasing (less in 10-bit mode). But I'd say unless you're sending your documentary to a broadcaster who asks for 4:2:2 or you're shooting in a situation where the compression artifacts are going to become noticeable, use the 4k Internal recording. The micro HDMI isn't the most rugged connector in the world and the YAGH thing uses the micro HDMI to convert to SDI anyway.

[Dave Partington]

A lot of people seem hung up on needing "broadcast quality 4:2:2" but having spoken at length to many editors for TV programs they simply don't care as long as it comes to them in a 4:2:2 wrapper (typically ProRes or DNxHD). Even GoPro footage re-wrapped makes it to the TV screens more often than you'd think.

So, before getting too hung up on this, do you really 'need' 4:2:2 or do you just 'think' you need it?

[Gary Huff]

Originally Posted by Dave Partington

So, before getting too hung up on this, do you really 'need' 4:2:2 or do you just 'think' you need it?

They just think they need it.

[Vishal Jadhav]

The way i think about it,

In case you have the space to start with record in 4k then you can get it down in post at 1080 or what ever is the necessary requirement, however the reverse is not possible .
The quality on the 4k is really good and i have had a few places where i recorded in 4k and down scaled it in post to 1080 p and recorded in native 1080 p and the 4K downsized looks better to the eye. This may just be my eye, but given a choice i would shoot in 4 K all the time.
on the GH4 now the only things i shoot in 1080 are the slow motion and the ETC image .
Just may keep your footage future proof for sometime.

cheers
vishal

[Paul Mailath]

Originally Posted by Gary Huff

Not going to get 10-bit from the 8-bit source. At best it will help cover up any banding. Anything remotely associated with EOSHD needs to be taken with a huge grain of salt.

TANSTAAFL.

I have my doubts about the EOSHD claims but he actually quotes David Newman in a twitter conversation -
Discovery: 4K 8bit 4:2:0 on the Panasonic GH4 converts to 1080p 10bit 4:4:4 - EOSHD

and yet the general discussion on this seems to have died??

[Vishal Jadhav]

Paul,

I have done the 4k and downsized it to the 1080p however i dont see that the banding goes off so its not true 10 bit, well i am very new to all this and hence i may be way off.

does any one have the best method to downsize the 4k to HD in 10 bit ?

cheers
vishal

[Gary Huff]

Originally Posted by Paul Mailath

and yet the general discussion on this seems to have died??

Yes, because people who tried it reported that they saw little difference in grading capabilities.

At most you'd get 444, but you would never get 10-bit.