Sync problems PDW-700 (1080 25P) and Aaton Cantar at DVinfo.net

Ole Andreas · April 19th, 2010, 03:07 AM

Hello!

I am working as an operator on a tv-series. We shoot on the Sony XDCAM HD format (professional dics).

We are experiencing some sync problems - both when viewing proxys - and when logging the material in Final Cut. We use sync-boxes both on the camera (PDW-700) and on the Aaton Cantar sound recorder.
The problem is that the picture is delayed compared to the sound. It varies between 1 and 3 frames.
It is constantly at least 1 frame delayed (I guess this is because the high resolution picture needs more sampling-time than the sound (?) ). The other variable I dont know the reason of. Maybe the sound is recorded in a higher rate than 25 per second and therefore the picture "have to choose" which "soundframe" it will lock on to?

The logger sync up every clip on the clapper.
The one frame out of sync we could correct with a default delay in FCP, but the real problem is that the unsync varies.

Anybody has any ideas?

We are working handheld (mostly) and with to cameras. the DoP do not want to use the genlock (for some reason).

Thierry Humeau · April 19th, 2010, 08:14 PM

Just currious, you don't have a Sony digital wireless unit mounted in the camera slot-in by any chance? Even if not in use, there is a setting in the camera's WWR Settings page that when set to AUTO (default) could I think affect timing.

Uli Mors · April 20th, 2010, 12:46 AM

how long are those clips? Is it the start frame that differs from clip to clip or does it run out of sync while playing, too?

WHEN does the TC update?

In a recent music show we shot with an external Audio Harddisk Recorder as playback machine. This unit was TC master.
Since everything was edited in Media Composer, we had to avoid starting the camera recording BEFORE the audio unit ran. Why? Media Composer sees only the FIRST TC number, but not the changed TC (TC jump) in the recorded file (when the master starts later or is hooked up later or...)

Even if both units are in TC free run, the audio unit (or any other TC master) could differ 1 or 2 frames (dependend on its circuits) , bad if you start the cam BEFORE the TC master updates the TC from the cam for any reason. You simply won´t see the update in Media Composer.

I am not sure how FCP holds up with TC jumps, but you will see the TC jump in this case in Playback from the camera or a deck.

Perhaps my thoughts somehow fit into your problems...?

Uli

Ole Andreas · April 20th, 2010, 08:21 AM

Quote:

Originally Posted by Thierry Humeau

Just currious, you don't have a Sony digital wireless unit mounted in the camera slot-in by any chance? Even if not in use, there is a setting in the camera's WWR Settings page that when set to AUTO (default) could I think affect timing.

Actually we do have a Sony digital wireless sound unit in the slot on the back of the camera.

Good guess. Do you have any experience of changing the settings? Could we solve the problem that way?

I will take a look at this camera setting.
Thanks for the answer.

Ole Andreas Grøntvedt

Ole Andreas · April 20th, 2010, 08:30 AM

Quote:

Originally Posted by Uli Mors

how long are those clips? Is it the start frame that differs from clip to clip or does it run out of sync while playing, too?

WHEN does the TC update?

In a recent music show we shot with an external Audio Harddisk Recorder as playback machine. This unit was TC master.
Since everything was edited in Media Composer, we had to avoid starting the camera recording BEFORE the audio unit ran. Why? Media Composer sees only the FIRST TC number, but not the changed TC (TC jump) in the recorded file (when the master starts later or is hooked up later or...)

Even if both units are in TC free run, the audio unit (or any other TC master) could differ 1 or 2 frames (dependend on its circuits) , bad if you start the cam BEFORE the TC master updates the TC from the cam for any reason. You simply won´t see the update in Media Composer.

I am not sure how FCP holds up with TC jumps, but you will see the TC jump in this case in Playback from the camera or a deck.

Perhaps my thoughts somehow fit into your problems...?

Uli

The clips varies from 30 seconds to 3-4 minutes. I believe it is the start frame that are wrong and that it does not float within the clip. The logger syncs it on the clapper, and I think everything is allright after that operation. But it gives her more work though.

We update the TC every day with fresh batteries on both sync-boxes.
I will try to look at the TC on the playback from the camera to see if you are right about the tc jump.

Thank you for the answer.

Ole Andreas Grøntvedt

Uli Mors · April 20th, 2010, 10:31 AM

what are exactly the units you use?

Uli

Thierry Humeau · April 22nd, 2010, 08:27 PM

Quote:

Originally Posted by Ole Andreas

Actually we do have a Sony digital wireless sound unit in the slot on the back of the camera.

Good guess. Do you have any experience of changing the settings? Could we solve the problem that way?

I will take a look at this camera setting.
Thanks for the answer.

Ole Andreas Grøntvedt

If you have a digital wireless mounted in the slot-in, please check the TX Transmission Delay in the MAINTENANCE WWR page 09. The default is AUTO which means that recording to the disc will be automatically delayed by a few milliseconds to make up for the slight delay typical with digital audio transmission. Try setting this to 0, I am pretty sure this will resolve your issue.

Thierry.

Ole Andreas · April 23rd, 2010, 07:25 AM

We use an Sony DWR-S01D

Ole Andreas · April 23rd, 2010, 07:26 AM

Quote:

Originally Posted by Thierry Humeau

If you have a digital wireless mounted in the slot-in, please check the TX Transmission Delay in the MAINTENANCE WWR page 09. The default is AUTO which means that recording to the disc will be automatically delayed by a few milliseconds to make up for the slight delay typical with digital audio transmission. Try setting this to 0, I am pretty sure this will resolve your issue.

Thierry.

Thank you Thierry. I will try this as soon as I have the possibility.
Very good with the exact page number in the menu.

Ole Andreas

Thierry Humeau · April 25th, 2010, 07:12 PM

Glad to help. Aside from a 0 ms Transmission Delay, you may also try various settings because I am not sure I fully understand your audio setup. In any case, the fact that the delay is inconsistent tells me that the AUTO setting is responsible for this because the camera will adjust its recording timing dynamically to overcome any slight delay caused by the digital receiver unit. Are you actually using the digital wireless to receive reference audio from the Aaton Cantar? Also, are you using any digital wireless mics on your talents?

April 19th, 2010, 03:07 AM	#1
Ole Andreas New Boot Join Date: Apr 2010 Location: Oslo, Norway Posts: 5	Sync problems PDW-700 (1080 25P) and Aaton Cantar Hello! I am working as an operator on a tv-series. We shoot on the Sony XDCAM HD format (professional dics). We are experiencing some sync problems - both when viewing proxys - and when logging the material in Final Cut. We use sync-boxes both on the camera (PDW-700) and on the Aaton Cantar sound recorder. The problem is that the picture is delayed compared to the sound. It varies between 1 and 3 frames. It is constantly at least 1 frame delayed (I guess this is because the high resolution picture needs more sampling-time than the sound (?) ). The other variable I dont know the reason of. Maybe the sound is recorded in a higher rate than 25 per second and therefore the picture "have to choose" which "soundframe" it will lock on to? The logger sync up every clip on the clapper. The one frame out of sync we could correct with a default delay in FCP, but the real problem is that the unsync varies. Anybody has any ideas? We are working handheld (mostly) and with to cameras. the DoP do not want to use the genlock (for some reason).

April 19th, 2010, 08:14 PM	#2
Thierry Humeau Telecam Films Join Date: Apr 2006 Location: Washington DC Posts: 723	Just currious, you don't have a Sony digital wireless unit mounted in the camera slot-in by any chance? Even if not in use, there is a setting in the camera's WWR Settings page that when set to AUTO (default) could I think affect timing. __________________ Thierry Humeau, DoP Télécam Films www.telecamfilms.com

April 25th, 2010, 07:12 PM	#10
Thierry Humeau Telecam Films Join Date: Apr 2006 Location: Washington DC Posts: 723	Glad to help. Aside from a 0 ms Transmission Delay, you may also try various settings because I am not sure I fully understand your audio setup. In any case, the fact that the delay is inconsistent tells me that the AUTO setting is responsible for this because the camera will adjust its recording timing dynamically to overcome any slight delay caused by the digital receiver unit. Are you actually using the digital wireless to receive reference audio from the Aaton Cantar? Also, are you using any digital wireless mics on your talents? __________________ Thierry Humeau, DoP Télécam Films www.telecamfilms.com

April 20th, 2010, 12:46 AM	#3
Uli Mors Major Player Join Date: May 2006 Location: Germany Posts: 565	how long are those clips? Is it the start frame that differs from clip to clip or does it run out of sync while playing, too? WHEN does the TC update? In a recent music show we shot with an external Audio Harddisk Recorder as playback machine. This unit was TC master. Since everything was edited in Media Composer, we had to avoid starting the camera recording BEFORE the audio unit ran. Why? Media Composer sees only the FIRST TC number, but not the changed TC (TC jump) in the recorded file (when the master starts later or is hooked up later or...) Even if both units are in TC free run, the audio unit (or any other TC master) could differ 1 or 2 frames (dependend on its circuits) , bad if you start the cam BEFORE the TC master updates the TC from the cam for any reason. You simply won´t see the update in Media Composer. I am not sure how FCP holds up with TC jumps, but you will see the TC jump in this case in Playback from the camera or a deck. Perhaps my thoughts somehow fit into your problems...? Uli

April 20th, 2010, 10:31 AM	#6
Uli Mors Major Player Join Date: May 2006 Location: Germany Posts: 565	what are exactly the units you use? Uli

April 23rd, 2010, 07:25 AM	#8
Ole Andreas New Boot Join Date: Apr 2010 Location: Oslo, Norway Posts: 5	We use an Sony DWR-S01D