3D documentary filmmaking: how to sync two Canon Vixias with one remote

As mentioned, I selected implosion cams for our first 3D documentary – six (three pairs) of Canon Vixia HF 10s and 12 (six pairs) of Canon Vixia HF M31s – a little while back.

Next, we needed to figure out how to turn each pair on simultaneously (the duos will be positioned to capture the implosion of a condemned sports stadium in Brazil for the explosive demolition series Blowdown).

And how to turn them on without knocking one (or both) out of alignment.

The cameras need to sit at a 74 mm interaxial distance, right next to each other, for us to capture the footage we need.

This means they’ll be positioned too close together for use to easily access the viewfinder on the right camera, where the camera controls are.

Since each camera comes with a remote, we tried to use them to adjust the settings on each one (holding two, trying to point each one at the infrared sensor on its respective camera), but it’s cumbersome and awkward.

It’s a problem: we need four elements to be in sync between before we start recording for these shots to work: the two cameras have to have the same zoom, the same white balance, the same exposure, and the same focus.

The risk of losing one or more implosion shots – our big bang footage that climaxes the show – because the crew’s running around like mad, trying to calibrate and turn these 18 cameras on properly while preserving their alignment, is a risk I’m not willing to take.

So our stereographer Sean White discovered a work-around – a home-made infrared transmission system that allows us to control both cameras at the same time.

With sourced components off the Internet, a box has been built that will receive any infrared signal and transmit it through a split cable to two infrared sensors.

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Canon 7Ds – why they don’t work for our 3D documentary filmmaking

Argh! The Film Factory 3D Indie Rig we purchased for our B cam system to shoot our first 3D documentary has arrived and the Canon 7D DSLRs don’t work with it!

Here’s the problem: beam splitter rigs are extremely sensitive – anyone who works with them has undoubtedly discovered that you have to have perfect alignment of the two cameras to each other, and to the mirror.

To make sure they’re aligned, we need to use a 3D monitor – so we can see both cameras on the same grid.

The model we’ve purchased (and as far as I can tell the only one that fits our field requirements, tech demands and budget) – the Transvideo Cineform 3D Monitor – takes an HDSDI signal from both cameras and combines them.

The Canon 7Ds aren’t built to send this signal … so there’s no way to see them on the monitor.

Even if we could somehow convert the signal they do send to HDSDI, the monitor also needs these two signals to be genlocked – impossible with these models.

So yeah. We need new cameras.

Looks like we’re onto plan B – Sony EX3s. This system’s been tried before, so I have no reason to think it won’t work for us.

But the EX3s are heavier than the Canon 7Ds – more weight for our already-overburdened field crew.

Excess baggage is a necessary evil in the third dimension, to be sure.

Still, it would have been nice to take a bit of the load off.

Onwards and upwards.

3D documentary filmmaking – the great splitter rig DSLR experiment

I’ve chosen cameras to test with our 3D Film Factory BS Indie Rig, two main parts of the B cam system we’ll need to shoot our first 3D documentary.

We plan to mount two Canon 7D DSLRs on the Indie Rig, a mid-sized model that’s currently being shipped to our production house.

Our stereographer, Sean White, chose the middle-of-the-road rig because he was worried that a small one wouldn’t allow for enough coverage when using a wide-angled lens, that the cameras would “see” the inside of the beam splitter box.

And a large rig was out of the question for the event-based, run-and-gun industrial-worksite shooting that’s required Blowdown, the explosive demolition series we’re going to shoot. Our stomping ground will be a huge, condemned sports stadium in Brazil!

But there’s a huge potential downside to our mid-sized, non-refundable rig – if the Canons don’t work, logistically or qualitatively, we won’t be able to mount larger, higher-calibre video cameras because the rig’s not big enough.

But it’s a gamble we have to take – as far as we can tell, there aren’t any other systems like this … no documentary has been filmed this way, using a hand-held self-contained unit.

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Canon 7Ds – why they don’t work for our 3D documentary filmmaking

Argh! The Film Factory 3D Indie Rig we purchased for our B cam system to shoot our first 3D documentary has arrived and the Canon 7D DSLRs don’t work with it!

Here’s the problem: beam splitter rigs are extremely sensitive – anyone who works with them has undoubtedly discovered that you have to have perfect alignment of the two cameras to each other, and to the mirror.

To make sure they’re aligned, we need to use a 3D monitor – so we can see both cameras on the same grid.

The model we’ve purchased (and as far as I can tell the only one that fits our field requirements, tech demands and budget) – the Transvideo Cineform 3D Monitor – takes an HDSDI signal from both cameras and combines them.

The Canon 7Ds aren’t built to send this signal … so there’s no way to see them on the monitor.

Even if we could somehow convert the signal they do send to HDSDI, the monitor also needs these two signals to be genlocked – impossible with these models.

So yeah. We need new cameras.

(more…)