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4k and Atomos Ninja Star downsample


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Hey Guys,

i´m thinking about getting an NX1, my main issue is i dont want to transcode a hole day before i can start editing.

My questeion is, if set up 4k at the NX1 (or maybe GH4) will the ninja star automaticly downsample the 4k footage to 1080p and record it?(i would do this anyway in post, i dont need to crop, just want the detail from 4k)

I know there is the shogun but its way to expensive fo me at this moment.

Sorry for my bad englisch.

 

 

 

 

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I curious about this as well. I had heard that the ninja star downconverts 4K automatically, but have seen no tests to confirm this feature. Hopefully someone can chime in and answer, because it would be a very useful feature to have. Though I also hope they offer clean 1080p out on the NX1 as well at some point.

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The Ninja Star won't do any downconversion for you. The GH4 can downconvert it's HDMI output and simultaneously record 4:2:0 8-bit 4K internally while outputting 4:2:2 8-bit 1080p out the HDMI for the Ninja Star to consume. I can't speak for the NX1. But you need to feed the NJS a 1080p signal for it to work properly. 

So if you want this working on a 4K camera, as far as I'm aware right now your only choice is the GH4. The A7S can output a 1080p signal but won't do internal 4K recording.

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Has anyone hooked up the NX1 to an external recorder?  I'd like to see if the quality is the same as internal 1080p after conversion.  If so, a Ninja Star would be a great option until h265 gets wider support.

Just bought the NX1 kit, inquiring minds want to know.

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The Ninja Star won't do any downconversion for you. The GH4 can downconvert it's HDMI output and simultaneously record 4:2:0 8-bit 4K internally while outputting 4:2:2 8-bit 1080p out the HDMI for the Ninja Star to consume. I can't speak for the NX1. But you need to feed the NJS a 1080p signal for it to work properly. 

So if you want this working on a 4K camera, as far as I'm aware right now your only choice is the GH4. The A7S can output a 1080p signal but won't do internal 4K recording.

​Thank you :) got it

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Has anyone hooked up the NX1 to an external recorder?  I'd like to see if the quality is the same as internal 1080p after conversion.  If so, a Ninja Star would be a great option until h265 gets wider support.

Just bought the NX1 kit, inquiring minds want to know.

​Geoff CB told me that the NX1 doesnt have clean HDMI output yet. (hopefully there will be an update)

If you take a look at the Atomos HP http://www.atomos.com/discovery-what-cameras/ the only suportet device seems to the shogun and only 4k, no 1080p support.

 

 

 

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Yes that is correct. I have a Ninja Blade and it will not work at all with the NX1 because there is no clean 1080p out of the camera. I really hope they add support for this in a future update, as 1080p is surprising great on the camera.  

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Seems like the GH4 and the Ninja Star would be a nice couple...

Is there any REAL benefit grading with prores instead of using h.264?

in know with prores there is less processing power needed, but idont really care about that at the moment... my hackintosh seems to do the job well on h.264.

 

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If I'm recording straight to 1080p I prefer to use the Ninja Star with my GH4 - 4:2:2 makes a nice difference and the higher bitrate means fewer artifacts. Plus it seems a bit nicer to use the 1080p downconverted from 4k than to use the built-in 1080p. I haven't done aggressive testing on this, but I'm happy with the results. It seems to be on par with rescaling the internally recorded 4K to 1080p in a timeline, but with less post-processing so saves me time. It's not a huge difference but it really does sometimes give "the look" when the internal H264 would go a bit mushy (e.g. highly textured surfaces, fast motion, stuff like that holds together better). 

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​Don't you mean 4:2:2 10-bit? I was under the impression the GH4 did 10-bit HDMI out.

The GH4 does do 10-bit out, but won't record simultaneously internally with that setting.

It's been demonstrated multiple times that the advantage of 4:2:2 recording is FAR more significant than the nearly invisible advantage of going from 8- to 10-bit recording, so 4:2:2 8-bit external (plus the 4K 4:2:0 8-bit internal) is in my opinion an astounding combination of both workflow-ready 1080p production-grade footage and 4K archival at exactly the same time, with zero transcode time. 

Of course, it'll be even easier when Atomos gets their act together and turns on HDMI record triggering for the Ninja Star and Ninja 2 devices using the protocol they invented in the first place, so you only have to hit one record button... 

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Guest Ebrahim Saadawi

StudioDC: When you're recording 4K internally at 2.3x crop, does the GH4 output a 1080p image at the same crop? that would mean you'd be getting a 1:1 sensor readout and much sharper image than internal 1080p, you even say it's as good as the 4K. Is this the case? it'd be an amazing way to get sharp 1080p without the transcoding process at ProRes 10bit 422

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StudioDC: When you're recording 4K internally at 2.3x crop, does the GH4 output a 1080p image at the same crop? that would mean you'd be getting a 1:1 sensor readout and much sharper image than internal 1080p, you even say it's as good as the 4K. Is this the case? it'd be an amazing way to get sharp 1080p without the transcoding process at ProRes 10bit 422

​Yes, the 1080p output is an exact scaling of the 4K FOV. I doubt it's a 1:1 sensor readout, it's probably (but I'm not certain) an in-camera downscaled 4K. Perhaps I misunderstand you, but if there's 4K pixels in there, how could it be a 1:1 readout at 1080p? 

But, I can confirm that, without specifically pixel-peeping (as I haven't done a full side-by-side comparison, the image off the Atomos recorder is every bit as good and usable, optically and colour-wise, as downscaled 4K in my timeline, so I do agree that it's a simple, excellent, and very convenient way to get that lovely sharp 1080p look that downscaling 4K gives you without any transcoding necessary. I use it all the time when I'm travelling and have to edit on laptops - I can edit a 1080p timeline fine on my Macbook but cannot edit 4K in realtime, so this saves me a LOT of time on the go. Having the 4K copy as a master archival and backup is just icing on the cake.

If I get some time later on I'll put the camera in 4K photo mode, record a few frames on both devices, and put up a side-by-side so you can see. I can't promise when I'll get one of those round tuits, though. They only sell square ones here in Berlin, it seems.

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It's been demonstrated multiple times that the advantage of 4:2:2 recording is FAR more significant than the nearly invisible advantage of going from 8- to 10-bit recording

That's really interesting. In the samples I've seen, at least, the difference between 8-bit and 10-bit has been hugely obvious (256 shades of gradation per color channel vs 1024 shades), whereas I just see slightler thicker color in 8-bit 4:2:2 footage.

Do you have links to any such demonstrations between the two? Because if 4:2:2 is really what I'm responding to, that's much easier to find than 10-bit.

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