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GH4 DR on external 10 bit 4.2.2?

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Jacob--

 

Got it, that makes sense about the lag.. thanks.

 

jcs--

 

Watching that Zacuto video just to hear the Panasonic guy say it :)

 

09:52 <=  "If you want access to a true 4:2:2, at 10bit, even at 4k.. you can output that over the HDMI port."

 

Said the guy wearing a Panasonic shirt. 

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Hi Matthew. The colours look superb and low light performance impressive. But I think perhaps your 4K video is a better case for using a 1080 Ninja than Jacob's clip! 12GB for 2 min and a rig that makes smooth panning impossible is not something I need in a hurry!  ;)

 

Do you think there are any benefits re. low light performance (or anything that isn't resolution for that matter) in recording 4K 10bit externally instead of downsampling 4K directly to a 1080 Ninja? It looks like you work for Panasonic - it would be very interesting to hear your take on this.

Hi Matt, I'm not Matthew, I just posted this link from vimeo ;)

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Guest d5f8611fa423d0e628c016f9d5c93b47

Hi Matt, I'm not Matthew, I just posted this link from vimeo ;)

Ha ha yes I realised that just after I posted it!  :rolleyes:

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Hi guys, could you do the following for me (right now i don't have my computer for some time) take this sample 10bit 422 footage, color grade it quite haviliy (but not to the point when it brakes), export. Then exoprt the same (ungraded) sample to something 8bit (e.g h.264), than apply the same amount of grading, export. (or maybe there's a simpler way to do it). I'd like to see the difference. Thanks in advance.

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Guest d5f8611fa423d0e628c016f9d5c93b47

matt-

 

Yea, it kinda does answer the question. Based on that test, since 8bit 4k downscaled in post seemed to be the best for killing moire, 4k 10bit downscaled in post to 2k should be even better, but what a waste of space.

 

It seems like the hardware based undersampling is best to avoid.

 

Personally I thought there was only very marginally less moire in the 4K downsampled in post compared to the 4k downsampled to the Ninja. As you say, the benefits vs mbps aren't too attractive. I think you do VFX though (?) so your needs are probably quite specific?  :)

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Guest d5f8611fa423d0e628c016f9d5c93b47

Ahh - I see the confusion now because wasn't clear in my description.

 

Camera menu says:

 

HDMI Rec Outpu t> 4K Down Convert > Auto/1080p/off

 

 

 

 

Ahh, so it's the GH4 that is undersampling.. 

 

I think initially Jacob (and others on this thread) were just clarifying that the GH4 was set to 4K 'shooting' mode rather than 1080.

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Guest d5f8611fa423d0e628c016f9d5c93b47

This thread has some info on current compatibility with Ninja.

 

Atamos only received their GH4 test unit a few days ago, so no doubt there will be more comprehensive info soon.

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Just curious if any has used  a BlackMagic HyperDeck to get 4:2:2 out the camera? Might be a cheaper option as compared to the Blade, but not sure about the lack of ProRes.  The 10bit looks likes it's going to give the GH4 a massive advantage over the AS7 and will be the saving grace of this camera.

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I'm also very curious about the recording onto Ninja Star & Shogun. Could be an amazing package with the GH4. I think I bash my GH3 images to the brink with colour grading, so more power = happy Olly!

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Doesn't outputting 10 bit disable in-camera recording? So if recording 10 bit to a Ninja Star you would have no way of reviewing your footage bc the Star doesn't have a screen... this seems rather annoying. Am I thinking about this wrong?

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Doesn't outputting 10 bit disable in-camera recording? So if recording 10 bit to a Ninja Star you would have no way of reviewing your footage bc the Star doesn't have a screen... this seems rather annoying. Am I thinking about this wrong?

 

Yes - 10 bit output disables internal recording - so that's certainly an issue to be aware of. 

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Doesn't outputting 10 bit disable in-camera recording? So if recording 10 bit to a Ninja Star you would have no way of reviewing your footage bc the Star doesn't have a screen... this seems rather annoying. Am I thinking about this wrong?

good point!

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Personally I thought there was only very marginally less moire in the 4K downsampled in post compared to the 4k downsampled to the Ninja. As you say, the benefits vs mbps aren't too attractive. I think you do VFX though (?) so your needs are probably quite specific?   :)

 

Yes, I do, the moire was subtle btw and the picture looks incredibly sharp otherwise. 

 

 

I examined the original GH4 422 10-bit clip in PPro with contrast at 200 and brightness pulled down: the hair is perfectly fine- no sampling issues, about as perfect as is possible. 

 

Just doing a little test. Not pointing out any "sampling issues" that are deal-breakers with the camera.. I'm not trying to criticize the quality of the GH4. No disrespect. Simply noticed that there were subtle scanlines in the signal from the UHD to 1080p scaling and this is something that might make a difference for anyone that is considering getting the Ninja Shogun.

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Thanks to you all, I will try setting my GH4 up for 4k and record with my shuttle II and Ninja II at 1080P.

I never thought of this possibility of improved output before.

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Yes, I do, the moire was subtle btw and the picture looks incredibly sharp otherwise. 

 

 

if it were only for sharpness, all we would need is the GH4 having an EXT TELE CONV of  x1.2  and internally recording 1080P

 

this would use the native pixels of the 3840*2160, and downscale it to FHD, like it does now on the HDMI output..

 

a 'reasonable' upgrade request...?

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I have my GH4 sitting on a TriPod

When it is hooked to a Shuttle II

I am able to record DNxHD 1920x1080 P24

4:2:2 at 10bit 195Mbps, No sound

 

When it is hooked to a Ninja II

I was able to record Pro Res LT 73Mbps

188x1062 P24 with good sound

4:2:2 Variable bit rate? 1.46 Pixel*Frame

The Pro Res out put actually looked slightly better

 

Then I tried HiQ

1888x1062 P24 at 166 Mbps

4:2:2 Variable rate 3.395 Pixel*Frame

 

They all showed lots of artifacts in the low inside light

 

So then I just pressed record on my GH4

I got 3840x2160 P24 at 106Mbps

4:2:0 8bit rate 0.400 Pixel*Frame

Good sound and a better Picture

 

On all of these 24fps was actually 23.976

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So, I thought I would try ProRes on the Shuttle and it was slightly better.

OK, How about Uncompressed?

 

Here is what MediaInfo shows:

1888x1062 at 24.0 fps (not 23.97)

a whopping 1057Mbps

4:2:2 at 10 bits

22.063 Pixel*Frame

The Audio is recorded on 16 channels with 24 bits so maybe I am listening to the wrong one?

Still no sound through the Shuttle but an external record is best anyway?

This gives me the best external recording that I can get from what I have.

 

Conclusion: I have not been able to record 4k downsized to 30fps (29.97) so far.

But the Ninja does record DNxHD 8 bit 4:2:2 1888x1062 P30 when the GH4 is set for 1080 P30.

 

Wait for the Atomos Shogun to get the most out of 4k.

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