Quote Originally Posted by theorib View Post
If you don't want headaches, always have one sync box straight to camera and one going to the recorder, unless you are using good high end recorders like Sound Devices or Zaxcom which have rock solid timecode.
This is really good practice, and something I insist on doing for my shows, even with the big boy cameras.

Having an external clock fitted full time ensures you're not relying on the internal clock of the camera. And aside from Alexa and the UMP, i've not found any internal clock to be accurate enough after 8 hours, despite what the manufacturer's claim. - I haven't yet really tested the P4K clock

When you have an external clock fitted to each camera it almost guarantees you won't have sync problems. Even on Alexa if you change the frame rate to an off speed and back again, you can still get into trouble with the internal clock sync.

So what I do is have an external clock for each camera and it stays connected.

You jam the external clock in the morning and you jam it again at lunch time, typically 6 hours later.

Ideally you have a genuine master clock and you have an external clock that generates TC that can be compared so that the master clock will also TELL you the drift and offset, but few bother with doing this. I find it helps with troubleshooting. This is what the Ambient does well.

They also make this but again the cost will deter most...

https://ambient.de/en/product/powerlockit/

It's basically a power distro / video distro system that also has a built in clock AND can record frame accurate lens meta data (currently only Zeiss CP3)

JB