Jump to content

Genlock for 2-cameras doing long takes - hardcabled or Sync box


Recommended Posts

It's been a while for a thread on Genlock.

Actual camera sync (not just timecode identification on frame1 in the XMP metadata of a file)



1. live video switching needs Genlock,

2. 3D camera rigs -- cameras need Genlocked for  in phase shutter and timecode sync.

3. shooting concerts, all-day corporate conferences, or long form documentaries with takes being 1-2 hours before media change means multicameras need to stay in sync and not drift.


Other than the old RED camera issues and ANYTHING older than 2011....

When you've done a shoot with 2 or more cameras with very long takes. 

Were there any very productive conversations in pre-production that ended up in production requiring and agreeing to using a Sync Gen?

Yes Genlock can interfere with the shutter and scanning processes of cameras and that's why I am asking since it involves Sound/Camera/Post.

Have production wanted to do a test with 3-cameras with Sync Gen and long takes during prepro when shooting longer than 40 min. takes?

Have any of you got the dreaded call from post about camera drift even though you know you have a great sound recorder with high accuracy?

How did that go? Were you blamed because 1 or 2 cameras out of 5 were not in sync?


With new smaller lighter TC boxes have Genlock such as 

Timecode Systems UltraSync ONE with a temperature controlled XO it is going to be more accurate than a camera itself. 

I started using daisy-chaining 2 cameras on non-stopdown 2 hour sit-down interviews so they would both stay in sync. I was also feeding them both TC. Then I started using a AJA GEN10. I have found the GEN10 was very specific for PsF vs P settings for certain cameras before they would see it and lock.

For most modern cameras that have GENLOCK IN have some of you other soundies used a AJA GEN10 (to hardcable Genlock) or Timecode Systems UltraSync ONE when using 2 or more cameras?

Have any of you gotten a AJA GEN10 and billed for it to provides a frequency clock reference to "synchronize the cameras" on a long take show? 


Did you also feed AES10 to your recorder via AES IN and stay in-sync with the AES sync generator?

Have any of you experienced Camera Dept. or DIT providing a GEN10 ?


On shows with HDSDI hardcabled to camera Is a Genlock cable and also a TC cable really that awful these days that you've gotten a lot of pushback from Camera Dept. when camera is on a tripod in a 1 or 2 location only day?

Has anyone experienced more accuracy with hardcabled Genlock instead of using a little box providing Sync and TC?



Link to comment
Share on other sites

I do a quite a bit of network news multi cam interviews with takes that go for an hour or two and have always used tc boxes and a smart slate. I have never used Genlock and have never had any calls from post regarding drifting. Cameras vary from Panasonic Vaticam LT to Eva Cams, to old school style HPX 3700 series and sony fs and A7s with canon c series tossed in. Basically whatever cam the network bureau camera guy is provided and if there is a freelance cameraman on the job, he brings what he has. This has been my experience for quite a few years. Concerts are an entirely different beast, and I could see why Gen Lock would be necessary due to hours long takes.

Link to comment
Share on other sites

As a guy who grew up seting up multicam shoots with BetaSP cameras recording ISO and sometimes feeding a switcher I always tried to connected camera genlock to a master generator. We had to for the switcher, of course. NTSC - never the same color. 


Today, and for the past 8 years or so, I very rarely genlock the cameras. We put the cameras in PsF, and rely on the frame syncs in the switcher to handle the timing. This is fine for the live mix but doesn't sync the cameras to each other. But I have never received a complaint about drift over time.


As an example, I just AC'ed a two camera documentry shoot this week for HBO using one Sony Venice and one Canon C500. It was a three hour continuous rolling interview while swapping out cards as we rolled. I put a Tentacle on each camera. I monitored the Tentacles along with the SD664 timecode on my phone. No drift. I guess I could have performed a clap or tone at the end of the shoot to test but as I say, I haven't had complaints. 


As an aside, if cameras need genlock I feel that is a camera department issue. When I am mixing sound, 40% of the time, I only worry about the mix and timecode. Well, and helping out the youngsters setup their shinny new camera that they haven't read the manual for, lol. 


Others may have a different opinion about who's responsibility genlock is and that's okay. 

Link to comment
Share on other sites

In the last 11 years, I've never been asked for gen lock a single time (then again, I don't usually do live events).  In the last couple years I've been using Denecke JB-1 boxes and I've literally had zero sync issues and not a single complaint from post about timecode drops or anything of that sort. 

Now that I've bragged about this, I'm bound to have problems soon though...

Link to comment
Share on other sites

In almost 25 years, I honestly don’t believe I can think of a time we genlocked field cameras for multi-cam shoots.  Even in the Beta days.  For any type of live stuff, the cameras(when using ENG style cams) are just hooked up with SDI going through frame stores/frame syncs.  These days, outside of old-dogs(like me) and engineers, most people probably wouldn’t know what you were even talking about if you asked about it.  Today, SOP is Tentacles on everything and/or slate or even just a hand clap.  No complaints.


I don’t think I’m exaggerating too much when I say that I think the last time I remember of a complaint about sync, was back when we were shooting Beta and someone’s camera was in NDF instead of DF.



Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...