SYNC problems with LCD monitor

Posted by Tania 
SYNC problems with LCD monitor
June 03, 2011 05:08AM
I have a SONY 46 inch LCD screen as well as a 30 inch MAC monitor.
I'm running FCP 7.03 on MAC OS X 10.6.7.
A 12 core processor, 24GB memory with a SSD disc.
Am currently working on a feature film. Shooting on Canon 7D @ 23.976fps
and am finding the sync between the two screens are very different.
We watch Rushes(dailies) on the SONY LCD.
I've been told:

The issue is with the delay it takes the TV to process the HDMI signal through the Bravia. This takes between 1 & 2 frames to do this.
If you were running a broadcast SDI monitor or a broadcast panel with HDMI this would have less than 1 frame of latency which would not be noticeable.
The reason this didn?t happen or was less noticeable with you older setup as it was running component and was only an SD card which processes faster.
As for a fix for this, using a Television as a monitor will not ever be in perfect sync with whats on your computer screen for the canvas window to match the TV, the only thing you can do is delay the audio which goes to the speakers as this is just ahead of the video on the Bravia.

This can only be adjusted using the delay within FCP.
Generally speaking, editors use the computer and a broadcast monitor to work with and then the client monitor (bravia) is a frame or two out of sync with this type of setup.
Without spending mega $$ you cant get a big broadcast monitor, 24? is the standard working size and these all run around $4000-$6000. If it would help you I could loan you a reference monitor for the next 2 weeks but need it back before the 14th of June as it is going interstate for a long term hire. This would have no delay and would run over SDI. Sync would be spot on.
IS there any other solution please?

In the mean time you will need to adjust the audio delay settings within FCP. Anywhere between 2 & 6 frames should be fine.

IS this the only option?
Re: SYNC problems with LCD monitor
June 03, 2011 10:57AM
The FCP idea is that you delay the computer display and send the video and audio out through the IO card for critical monitoring, which would be marginally delayed due to the signal path. The problem with consumer gear is that you can't genlock the Bravia, and there are, as you noticed, latency issues. On the other hand, I'm guessing you could delay one of the signals through the IO card (the one to the broadcast monitor), but that would be implemented by the IO card, and you would need to buffer the signal (which isn't part of the design of IO cards). Furthermore, you won't want to edit with a 5-6 frame delay in your signal, which you need to do to compensate for latency in the consumer TV.

Bottom line is that if you want properly engineered products, you need to spend on engineered products.
Re: SYNC problems with LCD monitor
June 05, 2011 09:40PM
Thank you "strypes".
I obviously have more research to do but your information is very useful.

Sorry, you do not have permission to post/reply in this forum.


Web Hosting by HermosawaveHermosawave Internet

Recycle computers and electronics