DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Canon EOS Full Frame for HD (https://www.dvinfo.net/forum/canon-eos-full-frame-hd/)
-   -   syncing 5DII and XH-A1 (https://www.dvinfo.net/forum/canon-eos-full-frame-hd/144629-syncing-5dii-xh-a1.html)

Jim Newberry February 25th, 2009 07:16 PM

syncing 5DII and XH-A1
 
I'm thinking about shooting some live music stuff with the 5D2 and XH-A1. I know how to sync the footage from both cameras if I slate the head or tail and shoot all the way through--but what if the 5D stops and starts during a song. Any ideas on how to sync, other than just eyeballing/guessing during editing?

Jon Fairhurst February 25th, 2009 07:22 PM

Use onboard audio waveforms for synchronization. Keep in mind that your audio will be delayed by 0.001 seconds per foot, in case one camera is at the back of the hall.

Michael Friedman February 25th, 2009 07:35 PM

Depending on how you are shooting you can try this trick....

When you start rolling on the 5D point it at the display of the XHA1 and record the timecode on screen. That way you will know exactly where to go to sync it up.

If the cameras are far away, it is worth it to bring a cheap monitor and a long cable to make it happen. You will save tons of time in post!

Let us know how it goes and how it intercuts. I am planning on the same combo so I am very interested..

Jim Newberry February 25th, 2009 08:39 PM

Quote:

Originally Posted by Jon Fairhurst (Post 1018524)
Use onboard audio waveforms for synchronization. Keep in mind that your audio will be delayed by 0.001 seconds per foot, in case one camera is at the back of the hall.

Do you mean visually comparing the waveforms in post? In FCP, or something else? I'm not sure how easy that would be if the 5D2 is shooting short clips. Do you have any tips for this?

thanks

Jim Newberry February 25th, 2009 08:41 PM

Quote:

Originally Posted by Michael Friedman (Post 1018534)
Depending on how you are shooting you can try this trick....

When you start rolling on the 5D point it at the display of the XHA1 and record the timecode on screen. That way you will know exactly where to go to sync it up.

If the cameras are far away, it is worth it to bring a cheap monitor and a long cable to make it happen. You will save tons of time in post!

Let us know how it goes and how it intercuts. I am planning on the same combo so I am very interested..

Ah, great idea. So the XH-A1 can output the timecode to a monitor while shooting?

Jon Fairhurst February 25th, 2009 10:52 PM

Quote:

Originally Posted by Jim Newberry (Post 1018564)
Do you mean visually comparing the waveforms in post?

Yes, exactly.

First, you'd listen to the audio. With music, you can generally match the song, so that gets you within 3 to 5 minutes. If you can match a lyric, that gets you within a few seconds. Next match the words and finally, the waveform.

In Vegas, this is fairly easy. Move the audio waveforms to neighboring tracks. Expand vertically, so each is half of the full height. Zoom out initially, adjust, then zoom way in and fine tune. If both cameras are shooting 30.00 fps, you will just need to get it within one frame of accuracy. If one cam is 30.00 and the other is 29.97, you'll want to sync as accurately as possible, since the frames will be walking past one another. That will minimize any error.

The timecode approach that Jim mentioned would be sweet in post, but could be a hassle if you need to lay a cable and mount a monitor. It really depends on your setup. If it's easy to do at the venue, go for it. You can still look at the waveform as a sanity check. If it's impractical, use the audio method. It will take a few minutes to sync all your clips, but the accuracy will be excellent either way.

John Benton February 25th, 2009 11:15 PM

I did this with the 5D & the XL-H1
converted to 29.97 in mpeg streamclip
then edited both in ProRes.
The audio was fine -
Problem became THE PICTURE
The 5D blew the H1's HDV out of the water.
I couldn't mix them!
a concert would be different though


good luck,
J

Michael Friedman February 26th, 2009 03:25 AM

Good stuff. Thanks for sharing. The HDV shot was quick but you can definitely see the bump. I am going to do side by side shooting this weekend with my A1 and a Letus adapter next to the 5D. After seeing your footage I realize it's not going to be a close contest...

Thanks

Bill Binder February 26th, 2009 03:12 PM

I've been manually syncing music audio in post for years in Vegas, and after a while, it actually becomes pretty easy, even if there's drift. So, in addition to the thoughts above, which I agree with wholeheartedly, here's a couple of other tips that relate to music specifically, but might also be useful more generally.

- If it's a short clip, I usually just sync something near the beginning and be done with it.

- If it's a medium length clip, I might try to sync on something distinguishing near the middle of the clip. This is done to minimize the maximum drift experienced at either end. (Sync at the head with x drift by the tail, then syncing in the middle means only x/2 at both ends.

- If it's a longer clip, or a clip with obvious drift issues (which will inevitably occur no matter what recorders are used even the same recorders unless you are jam-synced), then I usually sync the head, then go out to the end of the clip, and sync the tail by stretching/shrinking the audio until it syncs. Once you get the tail synced, then you know you have the whole thing synced.

- If you are actually mixing the audio from multiple sources, then watch out for phase issues. You may want to try flipping the polarity of one of the tracks to see how it affects audio (simple push of a track button in Vegas).

- Also, I think this was mentioned above, but watch out for delay. If the cam was in the back of the room and you are syncing to a soundboard source, if you get the cam's audio synced perfectly with the SBD's audio, the video will more than likely be off a little. You need to compensate for that. So, usually I sync using the audio sources, but once completed with that, you should actually watch the video and listen to make sure it actually looks correct. This is also something to keep in mind if you are recording the soundboard and ambient to the same recorder -- even though there will be no drift in that case (b/w the two audio sources) because they are being recorded by the same recorder, and thus the same word clock, if the ambient was in the back of the room, you will still have to delay the SBD (or move the ambient forward in time) when mixing the two sources.

- I've also personally run into cameras, usually of the consumer to HD or flash variety, where the audio/video sync of the cam itself is off by a frame or two. Usually not noticeable, but when syncing to other sources, sometimes it becomes obvious. Also, if I had to choose, I generally prefer video to be ahead of audio rather than the other way around, so when dealing with syncing and drift, I tend to error on that side of things.

- With respect to the actual syncing effort in Vegas. I agree with above. I get generally close at a zoomed out view, then zoom way into the timeline (arrow keys) and use waveforms for final sync if possible. It can be helpful to also zoom the waveform amplitudes up and down too (I think that's SHIFT arrows if I'm remembering correctly). Also, if you have any musical inclination at all, I find it useful to pretend in my head that I'm playing the instrument while I watch, the fingering, the breathing, if horns, the blasting, drums are great for this, focus on the high hat. If you're in that mode, where you are almost anticipating the hit hat hit, you can easily spot whether you've got good sync (you might have to render to get fully fluid motion/sound).

Anyway, there's my two cents on some of this. That said though, if you are shooting scenes, and lots of them with double system, you'd be a fool not to slate and log every take, otherwise you're life will be miserable in post for sure.

Jon Fairhurst February 26th, 2009 04:55 PM

Great post, Bill. Lots of great recommendations and 100% solid.

Regarding syncing drift in Vegas, for those who don't know the trick, sync up the head by dragging the clip, then sync the tail by holding the Ctrl key and stretch/squeeze by clicking and dragging the end of the clip. (If you don't hold the Ctrl key, moving the end just changes the out point.)

What could be faster and easier?

Jim Newberry March 1st, 2009 04:36 PM

I did a test the other night. The technique Michael suggested, of shooting the XH's LCD to get timecode, worked well, although not with all lenses. With a 24-70 on the 5D it was no problem, but I wasn't able to get the camera close enough (and in focus) with the other lenses I was using--85, 70-200, and 135. I like the idea of bringing a monitor to shoot the timecode off of, but that's only possible with the XH-G1, not the A1, right?

I wonder if I could do this with an iPhone--there's an app called Slate that looks pretty primitive but will generate timecode. Maybe if I shot the iPhone timecode with both cameras, it probably won't be dead on but will at least be in the ballpark...

Barlow Elton March 1st, 2009 07:20 PM

Quote:

Originally Posted by John Benton (Post 1018643)
I did this with the 5D & the XL-H1
converted to 29.97 in mpeg streamclip
then edited both in ProRes.
The audio was fine -
Problem became THE PICTURE
The 5D blew the H1's HDV out of the water.
I couldn't mix them!
a concert would be different though


good luck,
J

I've had the same problem. The 5D's picture feels *fat* and the H1's HDV feels *thin* and you really can't get them to intercut invisibly. And I'm not talking merely about DOF differences...it's just the core image differences.

Jim Newberry March 2nd, 2009 12:17 AM

Yeah, the 5D looks so much better than the XH-A1 (especially in low light) that the only way to cut them is if I degrade the 5D footage.


All times are GMT -6. The time now is 11:45 PM.

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