I’ve turned to the Sony EX line to shoot B cam for our first 3D documentary, after we discovered that the two Canon 7Ds we planned to use can’t send an HDSDI signal to our Transvideo Cineform 3D Monitor.

Two Sony EX3s seem to be an intuitive choice, since this model has genlock in capability.

But we’re shooting an event-based explosive documentary series, Blowdown, in a derelict sports stadium in Salvador, Brazil, so having our gear as light and portable as possible is top priority.

Our stereographer, Sean White, hit the blogosphere to see if there was any way to lighten the load. He found a lead on DoP Alister Chapman’s blog.

It looks like we can pair one Sony EX3 with a Sony EX1: the EX1 lacks a genlock in, but according to Chapman only one of the cameras needs to have it … we can send signal from the EX1 into the EX3 and then send both to the monitor.

The reason he tried it this way is that the EX3’s viewfinder, which can’t be removed, was preventing him from getting the cameras close enough together.

The EX3 can be genlocked to the EX1 by connecting the EX1’s Y channel of the component output to the EX3’s genlock in connector, he says.

This is great news for us – besides being able to get the cameras closer together, the EX1 isn’t as heavy, so if this hybrid system would lighten our crew’s load (already virtually unbearable – much heavier than it’s ever been before due to transition into 3D).

There’s one other problem with these cameras – they record to media at 35 MB/S, much lower than our broadcaster’s benchmark of 100 MB/S.

To get around this we’re going to capture the uncompressed signal and feed it to the nano3D, which, as I’ve said, can record up to 280 MB/S.

Sean’s testing the system as I write – will post video of it tomorrow.