Welcome to our community

Be a part of something great, join today!

Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Epics can't shoot 25fps !! (?)

B

Brent J. Craig

Well-known member
Joined
Aug 31, 2007
Messages
1,801
Reaction score
0
Points
0
Location
Toronto
Website
www.brentjcraig.com
I am working on a big 3D shoot and we have Epic M's on our "lightweight" rig (Yes, 86 pounds is lightweight in 3D). Everything worked perfectly in camera prep, and worked pretty-well during the first few shoot days. We had 4 shots out of 70 with sync issues that we wrote off to 'start-up pains', but that's it.

Today for some reason, with absolutely NO changes to our camera settings or gear, nothing would sync up. The cameras would always display TC, GEN and SYNC in green on their screens and would roll and cut normally. When checking the clips in RedcineX the sync between the two cameras would drift as much as 2 seconds on a 5-minute take (verified by test shots of a timecode slate.) It was as if one cameras rolled at 24fps and the other at 25fps - sync would start to drift right away.

We are required to shoot 25fps for our European broadcaster. After a solid day of trouble-shooting I can't help but wonder if Epics have major issues syncing at 25fps, or if perhaps we are the first to test this.

We tried:
-New camera body on the 'eye' where the sync was drifting.
-Firmware update from 1.6.42 to 1.6.44 (We can't use beta firmware for insurance reasons)
-New timecode generator (Deneke SB-T and Ambient ?something?)
-New Genlock boxes (Deneke SB-T, AJA Gen-10 and the Ambient box)
-New sync/genlock cables
-Cameras on AC and DC power
-Running with No timecode input - jammed the cameras and disconnected
-With and without the GigE LAN connection
-Factory resets
-Hardware rediscovery
-Different SSDs
-Lots and Lots of reboots!
-Calling the smartest DIT in the world
-Calling Red (Travis)
-Bringing in the head of engineering from a major rental house for the entire day as we tested.


If you have ever synced Epics at 25fps in a reliable way we really appreciate your help!

Questions:
-What did you use for TC and Genlock?
-What were your camera settings?
-What do Epics like for genlock? SD or HD? Trilevel? Wordclock? P or PSF?
-What could cause sync and timecode to drift?
-How, with an external timecode generator , could one camera's timecode drift while the other stays solid?

Thank you for any insight you can provide!

Brent
 
Last edited:
We have done a number of shoots at 25fps in 3d with a very similar setup..

I've sent this thread to the guy who is responsible for keeping my 3d stuff working so he can help.

I do think the cameras are not disconected (re TC) and we favour NOT T spliting either TC or Tri-sync.

Something is going horribly wrong as we have zero problms at 25 for 25.

Good luck and sorry to be low on help.

Michael L
 
Can you email me logs from both cameras?
deanan @ red dot com.
 
Michael Lindsay said:
I do think the cameras are not disconected (re TC) and we favour NOT T spliting either TC or Tri-sync.
Michael L
Click to expand...

We had been T-splitting both TC and Genlock. Tested the Gen-10 today because it has separated outputs for genlock. Haven't found anything portable that has more than one TC output, but we feel TC is less critical since it is basically an audio signal.

I look forward to hearing from your 3D guy. Thank you so much for your help!
 
Hi Brent,
It sounds like you have tried most things already but, as Michael L already said, we've been running at 25fps with no problem for some time here. Not very helpful, I know, but it can be done!
For reference, we use an Ambient Lockit to provide TC and Genlock. The TC output is T'ed, the Genlock (1080p25 Tri-level) we run through a DA (http://www.kramerelectronics.co.uk/products/model.asp?pid=78&sf=3).
Good luck and do let us know if/when you figure it out!
Kind regards
Campbell
 
Have you consider the chance of radio interference to the T-split cable?

I have had iPhone and other devices causing problem like this before to unshielded cables.

Just thought we look into that possibility.

Was there a cell phone within 10 feet of your cameras?
 
Michael Thornton said:
Have you consider the chance of radio interference to the T-split cable?

I have had iPhone and other devices causing problem like this before to unshielded cables.

Just thought we look into that possibility.

Was there a cell phone within 10 feet of your cameras?
Click to expand...

That’s what I was thinking that perhaps there is some significant EM interference (or lack of shielding) where something drops out? It seems like a pretty systematic error, and it’s all too easy to point the finger at SW/FW. With EM interference and cabled digital high bandwidth signals, connector design can have a disproportional effect on signal integrity. Also very long cables can be prone (in general)/subject to EM interference/signal degradation. You would think the bandwidth/EM interference should not be such a problem for simple synching?

IF you guys DO find a solution can you (please please….) post it here?

Thanks in Advance,

Eric
 
Michael Thornton said:
Have you consider the chance of radio interference to the T-split cable?
I have had iPhone and other devices causing problem like this before to unshielded cables.
Click to expand...

The problems magically went away at 24FPS with the same number of phones around. Also about 40 walkie-talkies that transmit at far greater power than a cell phone.


Michael Thornton said:
Was there a cell phone within 10 feet of your cameras?
Click to expand...

Is there anywhere these days that doesn't have a cell phone within 10 feet?
 
Is there anywhere these days that doesn't have a cell phone within 10 feet?
Click to expand...

I don't know what kind of reality show or set you have but on our sets, phone are to turn off.

The sound guy would pickup any phone even on vibrate.

As far as radio, their frequency are not as close to microwave as cell 3G/4G cell phone are. It's not the power level, it's the frequency.

I'm glad that going to 24p eliminate the problem.

It's seem phone(s) are not involve in this case.

Sorry for trying to help you. I'll remember you next time you have an issue and me with the answer. :|
 
Brent,

Can you mod the thread title since its a specific 3D problem on one camera in your rig? (EDIT post>go advanced)

It might freak out anyone in a PAL country NOT shooting 3D. Unless it's an actual camera issue and not 3D specific.

Thanks,

David
 
Hi

Quite interested in the resolution to this subject.

I dunno for 3D (as I have NEVER worked it)... Is it an option to test sync on TC + shuttersync, but avoiding Genlock?

Glad to follow all the steps you did.

Cheers and good luck!

Gunleik
 
what rigs are you using, is there a SIP, red sync cables do go bad, i have several that no longer work. did you make sure all the dips switches match on the gen 10's and the lockits. did you try a lockit for each eye? did you try different bodies. and who is the "best DIT in the world" and how did that person become/accomplish that in your eyes? and if it is not brook willard, then i disagree with you and finally a SIP engineer would be a much better person to trouble shoot this than a red tech or dit or 3d tech. the guys are 3ality are very good and actually the best person for sync is joe lewis at a company called general lift in el segundo, he has made the sync boxes for the hobbit. they are superior to anything on the market.
 
dino g said:
... and actually the best person for sync is joe lewis at a company called general lift in el segundo, he has made the sync boxes for the hobbit. they are superior to anything on the market.
Click to expand...

Thanks Dino, that was a usefull piece of info!

G
 
I've got synch issue back then in june 2011 with 25p in HDRx mode. We didn't use Trisynch/Gen nor TC jam... just the cam internal synch and an usual slate.

Are you shooting HDRx?

Pat
 
Patrick Tresch said:
I've got synch issue back then in june 2011 with 25p in HDRx mode. We didn't use Trisynch/Gen nor TC jam... just the cam internal synch and an usual slate.

Are you shooting HDRx?

Pat
Click to expand...

HDRx is not yet syncable for 3D.
 
Brent J. Craig said:
...Is there anywhere these days that doesn't have a cell phone within 10 feet?
Click to expand...

miles and miles mobile-free, power lines free, people-free, ... the only interference could be from the devils...Tasmanian devils, that is.

Welcome to my studio :) LOL
 
You must log in or register to reply here.
Back
Top