OT: Syncing with Flash/Audio thingy

CClub wrote on 9/4/2008, 12:21 PM
[I know that isn't a very technical description, but that's all I had.]

Several people have mentioned on this forum that they have used a device to create a camera flash at the exact time as it makes a loud sound, thus facilitating a nice method to sync several video and audio tracks. Is anyone aware of a company selling something like this?

Comments

nolonemo wrote on 9/4/2008, 12:43 PM
I'm not aware of any. I made mine by screwing a PC cable flash shoe onto ordinary clappers, putting contacts on the end of the PC cable and attaching them to the inside of the sticks at the end, so they touched and triggered the flash when the sticks were clapped. It's pretty easy, but probably not for someone who has zero DIY experience.
CClub wrote on 9/4/2008, 12:59 PM
Heyyy... you been talking to my family? Who told you that I had "zero DIY experience?" Okay, it's true. I can't assemble a McDonald's Happy Meal toy for my kids, and you want me to put together a PC cable flash shoe/contacts/clappers? What happened to capitalism; doesn't some company make this?
Chienworks wrote on 9/4/2008, 1:34 PM
Hey, just offer nolonemo $1000 up front and i'm sure he'll be happy to operate his 'company' and produce a total yearly output of 1 unit for ya! ;)
baysidebas wrote on 9/4/2008, 2:01 PM
You only need the audio portion for synching if you're running double-system sound. Otherwise a plain flash, without the slate, will suffice. Just synch up the video, and the audio will follow in lockstep. Even if you're recording audio separately, you may or may not need additional audio synch depending on the nature of the audio. If there is an easily discernible peak or pattern, use that.
nolonemo wrote on 9/4/2008, 3:41 PM
The beauty of the gizmo is when you are shooting with on-camera audio at distances far enough away to introduce audio lag, i.e, shooting from the back of an auditorium to the the stage. I think it's like a frame for every 30' of distance? Even a frame or two off is noticable with human speech. The gizmo lets you line up the flash (which appears in a single frame of the video) with the clapper audio spike to slip the audio into sync. Same applies if you are syncing external audio recorded by the house.

BTW, when using a flash to sync cameras, you should look for a small "manual" flash unit. The flashes built in to digital cameras have a "pre-flash" which means that you'll end up with flashes in a couple of frames.