HPX170 and Atomos Samurai 720P/24 challenge

T

Tim Visual

New member
Hi all,

I may be butting my head against the wall with this one, but I'm hoping some genius out there has a solution, if one exists.

I have an HPX170 that I'm using with an Atomos Samurai recorder. Here's the challenge. I would like to record to the Samurai in 720p/24 --- and not to the expensive P2 cards with the more difficult workflow. I set the recording format to 720P/24P, and the MCR Format to 720P/24PN (there is no 24P, only PN choice). The Samurai gets its instructions and feed from the MCR Format, through the SDI cable.

The Samurai doesn't recognize the 24P output from the camera, so it only gives two format choices to record: 1080P/29.97 or 1080i/59.94. So I choose one, and the result isn't great.

On most clips the motion is okay, but with certain types of motion, it appears real jerky. Upon closer examination, I find that there's some sort of pull down thing going on with frame duplication occurring at different intervals, depending on if I output at 720 or 1080i (in the MCR Format).

Also, if I bring the footage into After Effects, I get the frame duplication issue and jerky footage. If I bring it into Final Cut Pro X, it does some frame blending/interlacing thing which doesn't look too great either.

I'm thinking the combination of this camera and the Samurai just won't play together to get a clean 720P/24 without some funky conversion. The option is to shoot all at 1080P/30 and convert in post, BUT, if I don't need that res for my projects, it's a huge waste of P2 card and/or HD space on the Samurai.

Any ideas out there would be much appreciated. Thanks!

- Tim
 
I could be wrong here, but I believe the external output of the HPX170 is non-configurable and pre-set to 1080i. Barry will be able to answer your question more effectively.

Regarding P2, just remember a few things. Yes, the cards are ridiculously expensive given the progression of technology in general, but this is probably something you should have looked into before buying the cam. Going directly to a Samurai (and I presume, a laptop hard drive) is fine and dandy for fixed/planned shoots, but it's not really going to work for any type of run and gun scenario. Also, if the drive gets dropped or bumped, you risk losing everything.

The cost of P2 cards is high but the general consensus is that they last forever, are rugged (due to being solid state), and if you're making any kind of money as a videographer you should be able to cover the costs of the cards after a job or two.

And, as long as you're using a modern NLE, the workflow is fairly easy.
 
No, the 170 can output 720 over SDI, but it's always 59.94. If you're shooting 24p, there will be pulldown.

The Samurai records only 1080.

P2 is much less hassle. You don't get 10-bit, but not many take advantage of it anyway.
 
If you're going to use a Samurai, why not just put the camera in 1080/24p mode (note: *not* 1080/24pa)? The Samurai has the ability to automatically strip out pulldown from a 1080/24p signal and record it as native 24p.

As for the cost of P2, you could get three 64GB P2 cards for less than the cost of a Samurai. Then you'd have native recording, a smaller package size, no need for a second unit and its attendant cables and batteries, etc.
 
Thanks for your input guys. I appreciate it. Good points all. Excuse my ignorance, but I'm relatively new to the 170 (as well as this forum), so some of my questions may reflect that. Based on your comments and further investigation this morning, this is what I've discovered.


In the AV IN/OUT SETUP menu under CMPNT/SDI SEL it gives three options: Auto, 1080i, and 480i. My mistake, I found out from Barry's book this morning, was not using AUTO (I was using 1080i). AUTO forces the video output to match whatever the recording mode is, in this case 720P/24.


Once I set to AUTO, the MCR format changed on its own to 720p/60p. So that is what went out the SDI cable to the Samurai. So David, you're right when you say it can output 720 over SDI and it's always 59.94 (60).


After setting the camera menus as described above, the Samurai menu "saw" 720p59.94. So, the Samurai CAN record 720p, but it wouldn't without AUTO setting.


The resulting footage recorded to the Samurai was a 720p/60, with the effect of 3 duplicate frames followed by 2 duplicate frames, etc. (explained on p. 34 of the 170 manual). Once those duplicate frames are thrown away, I have true 24fps.


FCPX was able to see the issue and asked if I wanted to convert to 24p (in a pop up menu). I selected it, and the footage was perfect, no interlacing, no dupe frames, audio fine.


I haven't figured out how to interpret it in After Effects or Premiere Pro, and I'm not even sure if they can. So far I've had no luck. If not, this would mean that I'd have to bring through FCPX first if I wanted to edit in these Adobe Programs.


As for the astute comment on why bother with the Samurai, I've been asking myself the same thing lately. ;-) Actually, my thinking was that after the initial investment, I can get a 120GB SSD for $200. Not bad compared to P2. I was thinking the P2 cards would be a mirrored backup for the Samurai and I'd just clear off after each job. (This was something my vendor said could be done.) And I do like the workflow of popping the SSD out of the Samurai, into the caddy and doing a quick review of the Quicktime files, and dragging over just the selects. I'm sure there are good workflows with the P2's as well, but this just appealed to me.


As to Barry's comment on just setting the camera to 1080/24p and have the Samurai automatically strip out pulldown -- I really like this option the best. But when I set the camera for that, the Samurai's REC button is greyed out. On the Samurai menu I see the 3:2 notation off to the the left of the 1080p23.98, but I can't record. However, it's not greyed out when I select 1080i59.94 or 1080p29.97 on the Samurai menu. Not sure if I'm doing something wrong, but that's what I'm seeing. If there's a way to make this work, I'd love to know.


So, my workaround for 720p on the Samurai is acceptable if not ideal. And having said all this, I will probably get a couple 64GB P2s as per Barry's suggestion and be covered for all scenarios, run and gun and planned shoots.


I really, really appreciate all your thoughts as this issue has been vexing me for a while now. If any of you have any more observations, I'd like to hear of course.


Thanks again!
 
Quick followup. The tech support at Atomos just got back to me. Barry is correct, of course - ;-) regarding recording to the Samurai in 1080p24. The problem I had with the REC button being greyed out is I had to wave my hand in front of the lens to activate it. It works.

So in a nutshell, the bottom line for me is that I can definitely do a true 1080p/24 to the Samurai.

But for 720p/24, the only way to do it with this camera is with the 24 unique frames padded out to 60fps (going out the SDI cable to the Samurai). Then in post, I can strip out the duplicate frames for a true 24p with Final Cut Pro X. However, I have yet to figure out how to do that in Premiere Pro or After Effects CS5.5. (I haven't tried it in FCP7). However, the benefit of doing 720p this way is negligible if the reason for doing it is efficient use of disk space. 60fps of 720p are going to be probably close to if not more in file size than 24 frames of 1080, I would guess without doing the actual math. So I might as well just do 1080p24 and keep it clean and simple.

Thanks again for your help all!
 
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