C100: Matching C300 internal codec qty/size perfect balance on Atomos recorder with ProRes?

A

alohype

Veteran
So which settings/version of ProRes to chose while recording on Atomos recorder (Ninja/Samurai) to match a perfect balance of quality and size achieved in internal codec of C300? So getting 4:2:2 but with a closest to 50Mb/s stream (can be slightly higher but not lower - to match EBU requirements) without losing any quality. 220Mb/s is great when recording on hdd/ssd but when using upcoming Ninja Star it will be to much and fill up space pretty quickly.
Idea is to have C100 with Ninja Star on top and having footage recorded in codec of qty/size as close to the one on C300 as possible.
Thanks for help!
 
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Shoot progressive to ProRes HQ works out about 80 gig an hour. Hard drives are pretty cheap now, if your going to the effort of recording to an external recorder why not go with the best quality.
 
On Ninja/Samurai of course recording in highest quality - size is not a problem, but what I have in my mind is using a new Atomos Ninja Star. Memory cards have not such a high capacity (and cfast's are expensive), that's why my question.
 
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IIRC, the Ninja Star uses Cfast 1, not the painfully expensive Cfast 2 like the Ursa et al. But yes, it's expensive.

Because the C100 has, erm, a little 'texture' due to its 8 bit nature, the de facto choice is still the 220 Mbits per second ProRes HQ as the intra-frame recording doesn't bog down with all that 'diffusion dithering' going on. I've noticed IRE25-35 getting ugly when using a bit of gain at ordinary Common or Garden Prores 422, but remaining unmolested at ProRes HQ. This was during testing with my Pix 220. So, since getting my Ninja Blade, I've used it at that data rate habitually.

Quite frankly, you may not see the difference - many here claim not to. But this is why it's always good to test - in your set ups, run some footage at different data rates in different lighting situations, different action situations, and then pixel-peep at home (knowing you've used the highest rate you can for the actual takes).

Well lit, outdoor stuff will probably be fine at 422, well lit easy stuff like talking head presentations may only need LT. But remember that the C100 is a little grainy, but also comes with noise reduction settings. You may be able to play with the noise reduction to reduce the load on the ProRes encoder, but too little noise may make blotchy results.
 
Thank you MattDavis for very extensive answer. I was expecting that at LT you will lose some quality, but idea is to get broadcast acceptable footage (422 +50Mb/s) from C100. For controlled environment there is not problem to use HQ as even one card can be enough - just offloaded often to the laptop. Where I will find usage out of it is to use it for documentaries/live events where there are no possibilites to offload it and time to think about swapping card every 90 minutes. If the footage quality can match internal of C300 or at least internal of C100 (but having 422 with higher bitrate) while maximizing space usage then it will be well enough for me (or more precisely - for broadcasters).
Thanks! :)
 
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Aha, I think I spot one little wrinkle in your logic.

The broadcast specification of 50 Mbits per second assumes a LongGOP format such as MPEG2 (e.g. XDCAM). The Ninja Star and Blade record in an all-iFrame format - dare I say 'the opposite' of LongGOP - which is, by and large, 4x larger than the equivalent LongGOP format. Therefore, a 50 Mbit LongGOP format is the equivalent of a 200 Mbit iFrame format*. The LongGOP format sacrifices the speed of an editing format by making huge assumptions, but then delivers extremely efficient data-gathering. It has been, up until recently, extremely painful to edit LongGOP footage and so it was often transcoded to an iFrame format like ProRes or DNxHD in its higher iterations.

So, ProRes HQ at 180-220 Mbits per second and ProRes 422 at 120-150 Mbits per second are equivalent to MXF 422 at 50 Mbits per second using LongGOP, assuming 'average' conditions. Filming from a helicopter, filming a Ninja Apocalypse fight scene, filming your choice of huge rock band, different story. iFrame rules those roosts. But for most average assignments, a LongGOP codec is fine - and the rule is '50 Mbits'.

* We could debate this. 50 Mbits LongGOP could also equal 100 Mbits of corporate talking head, but never equal 330 Mbits of intense action/slo-mo-dust. LOL
 
Many, many thanks for your detailed explanation :) I really appreciate that. So far I know very little about codecs and what really lies behind them (as you could see from my mistake above). So that would mean that HQ is the only option and in that case Ninja Star doesn't seems like a great option for me any more. On cvp site there are preorders for Ninja Star and atomos cfast 1.0 media. 128gb is £178.80 and that would be for 1.5h only. So to get through one day I would need let's say at least 5 of them. That make the whole thing very expensive and a little cumbersome - swapping cards very often. One hope is that maybe sd to cfast adapters will work it (as someone mentioned on the forum) so that would change the whole idea again.
Thanks!

Side note: Could you give me direction which book to read to get proper, deep understanding of codecs, wrappers and technical foundations? :)
 
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We-ell, HQ is not the ONLY option. You need to get a feel for your lighting style, your shooting style, and which mode is going to give you acceptable results.

Yes, I do tend to default to HQ. But this week I used 422, and next week I may use LT. YOu need to develop a feel for what each codec is going to do with your footage, whether it be 'low light, high contrast', or 'cloudy day, low contrast' or 'my favourite chromakey setup' or whatever. There are no easy 'do this and you'll be fine' settings unless you subscribe to the highest common denominator. We can trim down the specification WHEN (and only when) we know what we're shooting and how we're shooting it. And that takes experimentation and testing.

Even today, I was testing (from footage I gleaned from a quiet spot in our schedule) just what the difference is in shooting chromakey in 4:2:2 vs 4:2:0 and using the FCPX keyer:


Yes, the Ninja Blade footage generates a more 'full' key, but will clients appreciate that and pay you the difference to bring that extra bit of kit out and deal with the post? Or are you on your own budget and need best bang for buck, come what may?

I think you'll be well served by a Ninja Star shooting 4:2:2 at ProRes 422, but you should know when to use 422HQ mode.

As far as a book or paper to read, I know what you mean, I'm actually writing stuff like this right now, but it will be behind a paywall. You may hear all about it soon for a June/July launch date. Not from me, but you may recognise it when it happens. LOL
 
I'm also pretty sure you can adapt standard (albeit fast) SD cards into the new CFast socket with an adapter with the Ninja Star
 
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