Shooting a 3D documentary: testing the green screen

Green screen action!

Writer Nicole Tomlinson stands in for a 3D green screen test

We’ve taken the Film Factory 3D BS Indie Rig Sony EX1/EX3 B cam setup for a full test run.

The mission: to see if the system can capture green screen footage for our first 3D documentary the way we want it to.

Stereographer Sean White mans the 3D beam splitter rig

We need these shots to create several of out our in-house visual effects, a style we prefer to classic documentary CGI because it allows us to explain extremely technical concepts in a photo-real atmosphere.

This means our transitions in and out of our footage are much more seamless … viewers can stay more immersed in the environment and focused on the story.

Here’s an example of our Blowdown VFX style:

Controlled Demolition Inc. President Mark Loizeaux outlines his demolition plan

The green screen footage we’ll need to include effects like this comes with an entirely different set of issues than the field shots we’ll have to tackle.

This environment is the most “studio” our event-based filming gets – the interviews aren’t scripted, but the lighting is set, the frame is stationary, and there’s opportunity for multiple takes.

But what we capture has to work in our compositor’s virtual environment or it’s completely useless.

Jakub Kuczynski, Parallax Film’s VFX artist, details these challenges:

We’ve thrown the footage over to post – we’ll see if it flies.

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.

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…)