External TC Sync Accuracy on EPIC 4.0.18

[ericyoung]

Hello,

What's the difference between Worldclock and Trisynch? Isn't Worldclock ok to genlock the Epic?

Pat

Word clock is a digital audio synching signal running at digital audio sampling frequencies. Tri-level Sync is an HD digital video synching signal running at HD video sampling frequencies. Epic doesn't understand Word Clock, and in any case Word Clock doesn't have video frame synch information, so would not be useful for Genlocking two or more cameras to start frames at the same moment in time.

 

[ericyoung]

what about the Ambient clockit ACL 202CT, should this sync with an Epic? Cannot get the sync icon to be green on the Epic, only Gen and TC.
thanks,

If you're using 25fps timebase in Switzerland, it may be because the ACL 202CT is an older model which does not output 25p Tri-level sync. Looking at the last page of an instruction manual:
http://www.cinegate.de/cinegate/cinelist/data/Dmanual_und1272551174.pdf

it looks like it can only output 50i or 25PsF Tri-level sync for PAL countries, which may well not be compatible with Red, which always deals only with true progressive signals. The green GEN and TC icons indicate a valid signal, but the blank SYNC icon indicates that the camera shutter start is not synched to incoming genlock.

[ Edit: Actually the ACL 202CT DOES output 25p Tri-level Sync according to page 7 of the manual - it's just not given as one of the examples on the Lockit itself ]

Alternatively, check your camera Project Timebase, the ACL 202CT Timecode framerate, and try the nearest Tri-level sync option to match those.

 

[Patrick Tresch]

Thanks Ericyoung, it makes sense now.

Pat

 

[ericyoung]

Thanks Ericyoung, it makes sense now.

Pat

Slightly confusingly Sound Devices' only audio recorder with a Tri-level genlock capability in addition to timecode, the 788T, lumps Tri-level sync in with audio Word Clock in the specifications. But they are meant for video and audio respectively.

 

[David Skidmore]

Sound is usually the department that provides an Ambient Lockit or a Denecke SB-T box, jammed from the sound recorder. It's generally $50 a day or less for rental.

Well if sound needs genlock to ensure they are frame-start accurate, I was just supposing you could use a lockit/sb-t to generate genlock for sound to sync to. However, it's sounding like the 788 will be the only recorder that will function in a genlocked environment, unless other recorders are able to take genlock from a lockit/sb-t/other genlock source.

I think some experimenting is in order.

 

[Antoine Baumann]

Thanks a lot for your time Eric. I've been puzzling this on and off for a few weeks and I finally got it to work .... oh well, I think ... at least the 3 icon (TC, GEN, SYNC) are green.

So it seems the Ambient Recording Lockit ACL202CT will sync with the Epic, well I only tested 25fps.
Ambient setup:
OFF OFF OFF ON OFF OFF OFF OFF
RED SW RIGHT RIGHT

Set the Epic to take the TC from external source
Set the Epic to take Genlock
Set the sync to be sync (not trigger), actually I'm not sure this is usefull as I don't use the sync bnc
Set the HD-SDI out of the Epic to 25hz

Thanks to everybody for his contribution.

 

[ericyoung]

Thanks a lot for your time Eric. I've been puzzling this on and off for a few weeks and I finally got it to work .... oh well, I think ... at least the 3 icon (TC, GEN, SYNC) are green.

So it seems the Ambient Recording Lockit ACL202CT will sync with the Epic, well I only tested 25fps.
Ambient setup:
OFF OFF OFF ON OFF OFF OFF OFF
RED SW RIGHT RIGHT

Set the Epic to take the TC from external source
Set the Epic to take Genlock
Set the sync to be sync (not trigger), actually I'm not sure this is usefull as I don't use the sync bnc
Set the HD-SDI out of the Epic to 25hz

Thanks to everybody for his contribution.

Apart from one too many "OFF"s (there are 7 DIP switches on the left) I think you have the correct settings for 25p, reading page 7 of the manual! I was confused by the Examples given on the Lockit itself not including 25p.

 

[ericyoung]

Well if sound needs genlock to ensure they are frame-start accurate, I was just supposing you could use a lockit/sb-t to generate genlock for sound to sync to. However, it's sounding like the 788 will be the only recorder that will function in a genlocked environment, unless other recorders are able to take genlock from a lockit/sb-t/other genlock source.

I think some experimenting is in order.

I think some other manufacturers make genlockable audio recorders, but don't know which ones.

 

[Antoine Baumann]

Apart from one too many "OFF"s (there are 7 DIP switches on the left) I think you have the correct settings for 25p, reading page 7 of the manual! I was confused by the Examples given on the Lockit itself not including 25p.

Yes you are right. Sorry for the confusion.
OFF OFF OFF ON OFF OFF OFF
RED SW RIGHT RIGHT

the only one I'm not sure is the last DIP sitch, but it seems it has to be off.

cheers,

 

[David Skidmore]

If you're using 25fps timebase in Switzerland, it may be because the ACL 202CT is an older model which does not output 25p Tri-level sync. Looking at the last page of an instruction manual:
http://www.cinegate.de/cinegate/cinelist/data/Dmanual_und1272551174.pdf

it looks like it can only output 50i or 25PsF Tri-level sync for PAL countries, which may well not be compatible with Red, which always deals only with true progressive signals. The green GEN and TC icons indicate a valid signal, but the blank SYNC icon indicates that the camera shutter start is not synched to incoming genlock.

[ Edit: Actually the ACL 202CT DOES output 25p Tri-level Sync according to page 7 of the manual - it's just not given as one of the examples on the Lockit itself ]

Alternatively, check your camera Project Timebase, the ACL 202CT Timecode framerate, and try the nearest Tri-level sync option to match those.

Yes, we were able to get an EPIC to sync with a 202. Remember, all the settings have to be identical on all outputs (EVF(or LCD)/HD-SDI/Project/etc) for Sync to work.

 

[Marc Wielage]

Well if sound needs genlock to ensure they are frame-start accurate, I was just supposing you could use a lockit/sb-t to generate genlock for sound to sync to. However, it's sounding like the 788 will be the only recorder that will function in a genlocked environment, unless other recorders are able to take genlock from a lockit/sb-t/other genlock source.

You have to wonder how the thousands of TV and film projects around the world that don't use Sound Devices gear are somehow able to make it work...

 

[David Skidmore]

You have to wonder how the thousands of TV and film projects around the world that don't use Sound Devices gear are somehow able to make it work...

By manually syncing.

 

[Marc Wielage]

By manually syncing.

Manual syncing is fast and trivial. As I've said many times, if you take :30 seconds to do each one, and you do 200 takes a day, it's 1.6 hours for an assistant editor. And bear in mind half of those will already be perfect. You still have to check them. I've done it myself -- it's not rocket science.

One forgets that for 90 years, there was no timecode with film cameras (for the most part) and all syncing had to be done by eye. I did that, too, and you can get extremely fast at it if you develop a skill for it. Heck, I've synced long shows completely by eye where there was no slate at all and I had to simply read lips. Not that hard for a good editor (which I am not). People make more of this than is actually there, and it truly is easy and simple to do. It does help when the sound files are identified with scene and take number, either in the metadata, the filename, or both.

Recently, The Hobbit has shot miles and miles and miles of footage that was completely synced by eye, because the cameras could not accept timecode, running at 48fps. You gotta wonder... how did they do it? My guess is skill and time. At least they clapped the slate.