Just confirming the Atomos Ninja does record 1080 25p?

Hmm. I don't think you're quite seeing the point here. Yes, the Ninja records ProRes, but no, it won't record 50p or 60p because the data rate is twice that of 50i and 60i. It won't encode these framerates to ProRes because it simply won't accept them. For every second, you have to process twice the amount of data. And even if the Ninja did let these data rates in, it wouldn't encode them. Everything would have to be (at least) twice as fast; twice as powerful.

So it's simply not true that ProRes will record to 220MBit/s whatever the frame rate and whatever the resolution.

Or have I totally misunderstood your question here?

Dave Shapton
Atomos
 
The Ninja encodes uncompressed video to ProRes & ProRes HQ has a maximum data rate 220Mbps with a maximum resolution is 1920x1080@60i. That is the ProRes specification & is independent of the source material you are encoding to ProRes so even if the Ninja could handle 1080@60p material it could only save it as 30p or 60i.

Perhaps I have misunderstood how the Ninja works. I had imagined that the uncompressed stream is buffered in memory while it is converted to ProRes & then written to the disk. If in fact the uncompressed stream is buffered to disk then converted to ProRes & written back to the same disk then indeed the disk could be a bottleneck.
 
Perhaps I have misunderstood how the Ninja works. I had imagined that the uncompressed stream is buffered in memory while it is converted to ProRes & then written to the disk. If in fact the uncompressed stream is buffered to disk then converted to ProRes & written back to the same disk then indeed the disk could be a bottleneck.
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Nigel, it doesn't work like that. I'm not going to go into detail here, but we certainly don't write to disk twice! Think of it like this: 60p contains twice the amount of visual data than 60i or 30p. The Ninja is a machine, and, just like any machine, you can't simply make everything work twice as fast! That's what you'd have to do (in fact you'd have to do a whole lot more than that!) if you were going to record 60p. In any case: 50 and 60p are not even broadcast standards. Nothing can play these framerates. I realise that the reason people mostly want these (unplayable) framerates is to generate slow motion, so, given that the Ninja (or any other ProRes recorder that obeys the same laws of physics) doesn't record 60p, what you can do is switch to 720p60 for SloMo, or record at genuine 50i or 60i, and use software to turn each field into a frame. This will reduce your vertical resolution but can still yield excellent results.

Dave Shapton
Atomos
 
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David, thank you for confirming that my assumption was correct & that your assertions that "the disks won't keep up" & that "The only way to do this would be to have a raid-array" were in fact incorrect. There are a variety of reason why this does not work e.g. Ninja processing could not keep up with the conversion, ProRes doesn't support 1080@60p etc but the disk being a bottleneck is not one of those reasons.
 
nigelbb said:
David, thank you for confirming that my assumption was correct & that your assertions that "the disks won't keep up" & that "The only way to do this would be to have a raid-array" were in fact incorrect. There are a variety of reason why this does not work e.g. Ninja processing could not keep up with the conversion, ProRes doesn't support 1080@60p etc but the disk being a bottleneck is not one of those reasons.
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Er, I'm not sure what point you're making here, and, just to be clear, I don't think I've contradicted myself.

Look, I'm trying to be helpful here, not have an argument. If you're clear now that the Ninja doesn't record 1080p50 or 1080p60, can we leave it here, please?

Dave Shapton
Atomos
 
Just thought I'd chime in to say that Ninja with AF101 worked without issues during a recent 2.5 week shoot, sometimes in pretty harsh conditions (wind, dust, heat). Used the recommended Intel SSD disks and a Hitachi HDD.
Shot in 1080/25p and I have now started editing the material on a 25p timeline in FCP 7 and so far so good, no issues there either (I did not de-interlace the footage).
It's great to be able to go straight to edit, no Log and Transfer needed. When you have terabytes of material, that does make a difference.
 
Sound advice and explanations (and a cool head!) Dave - appreciated. I have a ninja which works faultlessly with our AF101, and from a customer perspective I had no need to see footage as that has nothing to do with the Ninja and everything to do with the camera that shot it. Your website is excellent - and my recent firmware update very easy.
One quick question: I notice that Sandisk Extreme 120GB SSD's are approved - do you know whether the 240GB model is going to be on your list? it's a great price at the moment for whatever reason...
Many thanks,
Steve.
 
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