DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Atomos Ninja / Samurai / Shogun (https://www.dvinfo.net/forum/atomos-ninja-samurai-shogun/)
-   -   Some Samurai Blade Questions (https://www.dvinfo.net/forum/atomos-ninja-samurai-shogun/521976-some-samurai-blade-questions.html)

Billy Steinberg March 2nd, 2014 07:17 PM

Some Samurai Blade Questions
 
Hi,

My needs for a field recorder are probably different from most here; I will not be connecting it directly to a camera, but will be using it to record feeds in a remote production truck or broadcast studio. I'm USA based, so I'm dealing with US frame rates 99% of the time. I've read through the manual, and read up as much as I can, but I still have a few unanswered questions.

Timecode:
I'm confused about (direct) control of Drop Frame versus Non-Drop Frame. (For frame rates that support DF, of course). I presume that SDI embedded time code will be whatever it already is, and DF will be used when timecode is set to time-of-day (else it wouldn't remain time of day). The manual shows a "Use Drop-Frame" control in the screen shots for record-run and auto-restart modes, but in both cases it's "N/A". Can I actually set DF/NDF in the record-run and auto-restart modes, even though the pictures in the manual seem to indicate N/A?

Audio Channel Assignment:
Are SDI embedded audio channels recorded as individual single channel streams or one multi-channel stream?

Pull Down:
I record mostly 1080i59.94, but occasionally I set the cameras to acquire in 23.98pSF or 29.97pSF. I'm not expecting any surprises with 29.97p embedded in a 59.94i signal, as nothing can really tell the difference without watching or analyzing the cadence, but I have a few questions about what to expect when my cameras are set to acquire in 23.98p.

When I'm feeding "true" 23.98p to the Samurai Blade, there won't be any confusion with Pull Down, since there isn't any. When I'm feeding 59.94i with embedded 23.98p, I have two choices as to how I want to record it. I can record it as-is (59.94i), which will leave the Pull Down intact, with its characteristic cadence (motion judder) present. Or I can have the recorder figure out the cadence and remove the Pull Down and record the signal as "true" 23.98p. My decision on which way to record the signal is driven by how I plan on using the recording. Can I specifically instruct the Samurai Blade which way to record a 59.94i signal with embedded 23.98p frame rate?

Bad Cadence:
When recording a show with multiple cameras acquiring in 23.98p and the cameras outputting it embedded in a 59.94i signal with Pull Down added, on rare occasion one camera will have it's Pull Down out of sync with the other cameras. This throws the cadence off every time the switcher takes the offending camera (or the editor uses that camera in post). It doesn't matter to any of the broadcast chain (including the recorders), but I wonder what effect it has on Samurai Blade, particularly if it's set to extract the embedded 23.98p out of its 59.94i wrapper.

pSF / progressive:
All the progressive signals I will run into are not "true" progressive, but rather are progressive Segmented Frame (pSF). This is done (mostly) to allow broadcast monitors and recorders to deal with a slightly different signal than they're used to. How does the Samurai Blade deal with this on output, in both E-E and playback? If I feed a 59.94pSF signal with embedded 23.98p, what shows up on the output BNC while I'm recording? If I have the Samurai Blade set to remove the Pull Down, will that effect what comes out the BNC while recording? When I input (non-embedded) 23.98pSF, will the Samurai Blade record it as pSF or turn it into "true" progressive? The reason this is important to me is that 90% of the monitors this may be playing to will handle pSF just fine, but won't handle true progressive. *Note to Atomos: If it's not too difficult to do, and if it's not there already and I just missed it, putting in a "Convert p to pSF on output" setting would be very useful, at least to me. :)

Action on Loss of Signal:
What does the Samurai Blade do when there's an interruption of the input signal while recording? I would hope it closes the file and waits for the input signal to show up again. Does it resume recording after the signal comes back, or does one have to press record again? This may happen more than I'd like because sometimes an engineer has to send me a different source via a patch cable change rather than a synchronous router.

Thanks for any help!

Wolfgang Schmid March 6th, 2014 12:23 PM

Re: Some Samurai Blade Questions
 
The general guideline is, that you set the Atomos recorder to the same framerate as you use for the internal recording. So if that is for example 23,796 fps (24p), then use the pulldown function = set the Atomos recorder to 24p even if the signal is embedded in a 60i signal.

Same is true for a pSF footage.

If an interruption takes place, maybe with harddrives, you will see the skippy. The recorder will continue automatically to record the footage, even if some seconds of footage will be missing. You can avoid that by using a SSD.

Billy Steinberg March 6th, 2014 06:17 PM

Re: Some Samurai Blade Questions
 
Thanks for the reply, though I think you may have misunderstood what I was asking.

With regard to embedded 23.98 in 59.94i. I understand what's going on in the signal, what I was asking was if I could tell the Atomos which way I wanted to record it. There are some circumstances where I want to leave the signal as-is, in 59.94i, because that's how it's going to be used later, and everyone wants to see the motion judder. In other circumstances, I would prefer to just record the embedded 23.98p. Can I specifically instruct the atomos to record the signal the way I want?

The "interruption of source signal while recording" question really has to do with what the atomos will do. If I pull the input sdi cable to the atomos, count to ten, and connect it back up, how will the atomos respond. Does it stop recording and close the file when the signal is removed? Does it start recording again when the cable is plugged back in? Or does it just stay in record mode the whole time? Of course, while the cable is removed, nothing can be recorded (there's no signal to record!).

As I mentioned, my questions are probably a bit unusual, as I don't plan on using the atomos to record a feed from a camera, but rather from a dedicated feed in a studio or remote production truck.

Wolfgang Schmid March 7th, 2014 04:27 AM

Re: Some Samurai Blade Questions
 
Typically Atomos recommends to match the internal recording settings with the external recording settings. But it is up to you if you record the signal as 23,976p or 59,94i. You tell that the recorder simply by switching between the settings.

For the second question - I do not use SDI, so I cannot answer that for SDI. I use hdmi and have never tried to disconnect the hdmi connection during recording. Frankly spoken, I do not see why I should have tried that, since it makes no sense to me.

Docea Marius March 25th, 2014 01:24 AM

Re: Some Samurai Blade Questions
 
Hallo
a recommendation to the HDD if possible..HDD some atoms occurring on the site, no longer find in store.ssd yet for me it's too expensive,so we have to find a 500 GB HDD to be tested on ninja, if someone successfully uses HDD on ninja blade.I ordered an apple hdmi cable 1.8m..I prefer a shorter cable.I though that a wedding shooting HDD goes, someone has a negative experience about shooting the HDD to an event..if someone can post a few minutes of shooting RAW ninja blade .. or ninja2 and C100 avchd. try editing in adobe and see how it goes.

Thanks

Billy Steinberg March 31st, 2014 09:28 PM

Some Samurai Blade Answers
 
I received a reply to my questions from David in Atomos Technical Support the other day, and I wanted to share the info here. David understood and answered all my questions, and best of all, the answers were mostly what I was hoping to hear. I'm not going to repeat all the questions in this message, just look to the first message in this thread (above) to see them.

Here are David's answers:
Quote:

Hi Billy,

Regarding your questions;

Timecode:
HD-SDI -> timecode will be whatever comes in over the cable

Time of Day -> Drop Frame will be on

Record Run -> Can have on or off

Auto-restart -> Can have on or off

It will display N/A for frame rates that do not support DF


Audio Channel Assignment:
You are able to select which audio channels you wish to record to the .mov file and each channel will be on a separate track in the quicktime file

Pull Down:
When you are feeding a signal with pulldown applied you have the option of either recording the interlaced signal or doing pull down removal. This is selected by pressing on the top left corner of the screen where it will cycle between no PDR, 2:2 PDR and 3:2 PDR. You will need to wave your hand in front of the camera or pan side to side to help detect cadence for 3:2 PDR

Bad Cadence:
If the 3:2 cadence changes without dropping the signal (causing a relock when the signal returns) then the cadence will be out of sync and the footage will be unusable.

pSF / progressive:
Whilst recording the loop through will be the same as the input signal, PDR does not affect the loop through. If you have the Blade setup to do PDR, then when you playback the clip it will be true progressive. I will add "Convert p to pSF on output" to our feature request list.


Action on Loss of Signal:
The Samurai will stop the recording and display a 'skippy' icon on the main screen. When the signal is relocked recording will automatically restart in a new file.


I hope that clears everything up for you. If I missed something or was not clear let me know.

Regards,

David Klopsteins

Atomos Technical Support
I've pretty much decided that the Samurai Blade is what I want. Does exactly what I want and need, and at this price point I'm willing to overlook the lack of 3G SDI (or dual link) which I currently have essentially zero use for. The price on really great SSDs has come down to the point where a 1TB Samsung 840 Evo can be had for under $400. What's "killing" me now is the wait for NAB in a few weeks, to see if Atomos (or anyone else, I guess) is releasing something new that I would prefer. (It would be silly for me to not wait...).

George Odell April 4th, 2014 09:18 AM

Re: Some Samurai Blade Questions
 
Quote:

Originally Posted by Billy Steinberg (Post 1839287)
The price on really great SSDs has come down to the point where a 1TB Samsung 840 Evo can be had for under $400.

I don't see any Samsung drives listed as being compatible on the Atomos web site. Are you sure this model will work?

Billy Steinberg April 4th, 2014 02:03 PM

Re: Some Samurai Blade Questions
 
From the Atomos web site: click me.


All times are GMT -6. The time now is 02:50 AM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network