Syncing Timecode

FarCountry

FarCountry

Member
I have two HMC150 cams, and did a test on syncing the timecode between the two. I then recorded a series of camera flashes and looked at the files in FCP and found that the sync was off by 4 frames. I had audio echo and phasing as expected as well. NUdging one clip over solved it, but I a, a little disappointed.

Am I expecting too much from these cameras? At this level, and with the method Panny employed to sync the timecode, is this as good as it gets?
 
Well no you're not expecting too much. This camera has several short falls...

If this feature of the camera doesn't work right I'm going to be upset...
 
Pretty dissapointing =\ I haven't run across any of these problems yet cuase I haven't had to deal with them. I still hope all the pros outweigh the cons by a huge margin.. or at least the margin of 4 thousand dollars..
 
Jordan Berry said:
Well no you're not expecting too much. This camera has several short falls...

If this feature of the camera doesn't work right I'm going to be upset...
Click to expand...


Jordan- since you have two 150's, can you try a test like I did and see if you get the same result. All told, I think it took me ten minutes to set-up, shoot, transcode to prores, make a multiclip (or else do a 3-point edit into the timeline), and take a look? A mulitclip makes this easy so you can watch both clips simultaneously and advance them frame by frame together.
 
FarCountry said:
Jordan- since you have two 150's, can you try a test like I did and see if you get the same result. All told, I think it took me ten minutes to set-up, shoot, transcode to prores, make a multiclip (or else do a 3-point edit into the timeline), and take a look? A mulitclip makes this easy so you can watch both clips simultaneously and advance them frame by frame together.
Click to expand...

Yes I can do that today. After reading your post I was like... I've got to do this!
 
I've been syncing to a Denecke timecode slate with no problems and shooting double system sound with a Sound Devices audio recorder. I make sure that all the devices are set to the same frame rate that I'm shooting in (such as 24p/23.98), and slave all devices to the timecode slate. It works flawlessly, then in Final Cut I just right-click on the audio & video file and sync to timecode. I love it!
 
I thought the HMC150 only took a start time code and rolled from there bases on it's internal clock. I m assuming you pull the cable that brings te external timecode after doing the sync and that the camera once it tells you that external sync is successful, no longer uses the external signal.

Do I understand this correctly?
 
FarCountry said:
I thought the HMC150 only took a start time code and rolled from there bases on it's internal clock. I m assuming you pull the cable that brings te external timecode after doing the sync and that the camera once it tells you that external sync is successful, no longer uses the external signal.

Do I understand this correctly?
Click to expand...

yes
 
I am not sure how you got your empircial results but I've done many multicam synched shoots off both two cameras and synch slate and it's been really really good. Even pro stuff drifts a bit but it's within a second or so.. then it's pretty darn close. It's an eproxmation and then synching should take a second. Don't get too lazy and think it should be frame accurate.

As an example I shot something last year with two HMCs and after 5 days of shooting.. stopping starting and putting batteries off and on.. the two cameras were less than 15 frames off synch. I mean that's really friggin good.


Guys.. you have to understand what you are getting with a timecode synch. You are able to run and gun in two seperate locations and then come together and it's all pretty much right on and gives you a good gauge to where your synch is...


With a timecode slate it's been rock on and with two cams.. it's been close enough to really be useful..
 
One of my buddies has an HMC150 as well. we just opened the timecode menus and I hit both of the reset buttons at the same time. It only took about 3 tries to get it dead on. They have an internal clock running, so chances are you may never have to sync them again if you use continuous TC.
 
It'll just repeat and I think it's longer than that.. but not sure. It does need the internal battery to be working though to keep going when power isn't on. It will FAIL though if you have a battery run out while shooting or such... then you might have to jam sycnh again.


it was so easy to do on this camera.
 
I think you have to be realistic that if the two cameras are not "locked" to the same TC Generator they will probably drift. That holds true for most cameras I have worked with over the years. I think it is safe to say that a camera not running tape through a transport should probably be less likely to drift as much. But a second here or there on an NLE system....no problem. If you want live...switch it and cut it ...
 
That's what I had figured. Mine were off by four frames right from the start, so at 30p, that is only off .13 seconds or 130 milliseconds. That tells me that for some applications, a slate, camera flash, or other cue is needed to sync up to the frame. If there is a variation in the internal clocks (and there likely would be), then that will still drift off over the course of a few hours of shooting I would think.
 
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