I think Peter Kraft has the best fail safe by putting an audio track back to each camera this gives a good sync reference when things fall apart. I am editing a client's camera job where production recorded to 8 track hard disc and had no sound at all on some material! The grand plan was to sync it up later without having accurate time code on Z1s. There is always a challenge in life.

Clapperboards still have a place
 

On a recent shoot with 4 EX1's, since we couldn't genlock the cameras, we used a plain old clapper board. This let the editor sync all the cameras precisely in post. A bit more work, but at least it worked. Timecode can be off, regardless of the source and it is more precise to use a sync mark from a clapper (analog or digital) for perfect sync. The clapper board also gives you scene and take info (if you bother to include it) that is not necessarily there in the TC, something that editors appreciate.

Sigh . . . I guess you're all missing the point. We know about genlock and reference. The point was that if you could start all the same cameras at the same time running the same frame rate the images should match. Hey the timecode may be off but who cares . . . this is the new paradigm. Yeah I know all about broadcast do's & don'ts but if you had told me five years ago that we'd be shooting full hi-def resolution to SD cards and Kensington adapters, I'd a laughed out loud.

So back to my point. Starting 5 cameras rolling with one remote doesn't work. Will it work in the future as technology advances? You can bet on it!

Thanks for the discussion,
Tony

Ha! Good point, Tony!

IR remotes are not the way to do it. There are too many other factors that can affect IR remote performance, ambient light, distance, obstructions, reflections etc. Even if you use the very best broadcast cameras they will still drift.

In my recent 3 EX1 project, just before we started shooting, our timecode was set to free run, and reset "simultaneously" on "one, two three..."

It was good enough to perfectly synchronize all 3 of them, using the loud sound at the beginning that all cameras recorded. In Vegas, once I aligned the three tracks basing on this sound "peak" in the sound wave, I had all remaining events synchronized for several hours of recording (the rehearsal, and the main performance that we shot).