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best syncronization method

PostPosted: Fri Nov 27, 2015 10:51 am
by Michael H
Hi guys
I saw the tutorial regarding syncronization before shooting with turning/spinning the camera a few times back and forth a few times. I just wanted to know if there are any tweeks to that? just on how fast or slow you should spin etc? I just need to have my stuff synced as best as possible.

Cheers

Michael

Re: best syncronization method

PostPosted: Fri Nov 27, 2015 11:01 am
by DesignGuru
Great question, I was about to ask this but glad you have done so.
What also confuses me is that in the tutorial they say to do this in the start and end of video + clap. What confuses me about this however is that they then select half way in the clip and do a stitch process with 20 seconds selected both ways but that would not cover the start or end of video. Am I the only one that doesn't get that?

Re: best syncronization method

PostPosted: Mon Nov 30, 2015 1:05 pm
by Michael H
I think I will do 3 claps now but would still love to get some more insight

Re: best syncronization method

PostPosted: Tue Dec 01, 2015 1:17 am
by OpusMcN
I'm using GoPros and gave up on claps. The audio can be several frames out from the video. A quick roll of the camera unit (about 2 seconds, about 45 degrees in all directions) gives me really good sync in everything I've tried so far. If you can see simultaneous movement in all 6 cameras than it should find it.

Re: best syncronization method

PostPosted: Tue Dec 01, 2015 11:33 am
by crazy_rabbit
I have gone to using flash to 'flash' the correct frame on all the gopros. The problem with motion sync is that it doesn't work when using really wide angle lenses (or perhaps I'm not spinning fast enough?) With regular go pros I get fine sync (great sync actually) with motion detection but using stock gopro lenses, once I change the lenses for something wider, the motion detection no longer works.

Audio sync works well as long as you don't have lots of cameras and lots of motion. Otherwise you get jiggle city.

Flash sync is more time consuming to sync up, but much more precise than audio, and probably more precise than motion as you get truly frame accurate syncing. That said if you use lots of cameras and lots of motion, higher FPS is better.

Re: best syncronization method

PostPosted: Mon Jan 11, 2016 10:19 pm
by bartch
I use a little metal toy clicker, worked perfectly so far.
Image

Re: best syncronization method

PostPosted: Wed Jan 20, 2016 9:33 pm
by jesusrg
Best sync method so far is flashing 2 or 3 times all cameras at the same time, with led light for about 0,5secs each flash, no normal flash cause cmos problems of line scan rolling shutter, then sync manualy, i had to make myself an app to convert the minutes/seconds to miliseconds and put that on the sync part of autopano. That being said sometimes, depends of the movement, one camera can be out of sync by 1/2 frame, so you have to chose with which frame is ok.
Best regards.
Jesus.

Re: best syncronization method

PostPosted: Thu Jan 21, 2016 3:41 pm
by crazy_rabbit
With flashing the CMOS with regular flash I still have a clear frame where the flash "starts".

Doesn't this workflow slow you down considerably? Do you trim each video file to where the flash starts in another program? Or do you search for it in AVP frame by frame?

Re: best syncronization method

PostPosted: Fri Jan 22, 2016 10:41 pm
by fabiobellotti
Hi....for me the best method (we use a 2/3/4 modified gopro hero 4 black) is:

- gopro remote: start recording
- gopro remote: stop recording
- hand claps (let's say ciak eheheheh)

I don't know why but there's a sort of lag time on the first time you try to record by the remote....if you "fake" the first, the second only has 2/3 frame of difference between cameras. With this difference, the clap is enough to reach a good sync

Re: best syncronization method

PostPosted: Wed Mar 09, 2016 3:59 am
by aquabluleo
DesignGuru wrote:Great question, I was about to ask this but glad you have done so.
What also confuses me is that in the tutorial they say to do this in the start and end of video + clap. What confuses me about this however is that they then select half way in the clip and do a stitch process with 20 seconds selected both ways but that would not cover the start or end of video. Am I the only one that doesn't get that?


Same here...are we missing something...?

Yhks

Re: best syncronization method

PostPosted: Wed Mar 09, 2016 4:51 pm
by martin.arnoux
Hi,

The dual audio clap (start / end) is just for safety raisons. You can use the beginning and the end for the sync but not both.

They should give you the same result when it's accurate.

Hope it helps,

Martin

Re: best syncronization method

PostPosted: Thu Mar 10, 2016 12:57 am
by aquabluleo
OpusMcN wrote:I'm using GoPros and gave up on claps. The audio can be several frames out from the video. A quick roll of the camera unit (about 2 seconds, about 45 degrees in all directions) gives me really good sync in everything I've tried so far. If you can see simultaneous movement in all 6 cameras than it should find it.


A quick roll of the camera unit (about 2 seconds, about 45 degrees in all directions)
Do you spin them only in one direction ex: clockwise?
So you angle camera rig on a 45 degree and rotate clockwise and repeat for all directions?

I saw a tutorial which just rotates left to right real quick and others 360 rotation in one direction.

If your process works...I want to make certain I understand it...
Cause in my tests audio worked best on freedom 360 6 gopros...

Thks