The mini beam splitter rig: portability for 3D documentary filmmakers

The mini beam splitter rig concept we came up with to film elements of our first 3D documentary has come to fruition.

We decided to try and build because the thought of moving and setting up our Film Factory 3D Indie BS Rig for one or two close ups is just too painful. Now we can use this smaller unit to shoot these components for the explosive demolition series Blowdown and save schlepping the full-sized rig around the Fonte Nova Stadium in Salvador, Brazil for when we’re shooting extensive B roll in one location.

The goal was to custom-design a rig that would house two Canon 7Ds and that was small enough and light enough to be operated by one person, handheld.

To achieve this, the mini beam splitter rig:

1) Has customized aluminum rails that aren’t as big and fat as the ones on the Film Factory Indie rig.

2) Is bolted and tweaked specifically for the dimensions of the Canon 7Ds.

3) Has a smaller box.

4) Is designed so the second camera is underslung – easier to handle because it’s not as top-heavy.

5) Allows us to get camera lenses closer to the mirror.

It was whipped up in a couple of days, and it’s not pretty – but it is portable and robust. We’ll see if it works.

Shooting a 3D documentary: Film Factory 3D Indie BS Rig mirror issues

So … we’ve broken the backup mirror we purchased for our Film Factory 3D Indie BS Rig to shoot our first 3D documentary.

This wouldn’t be a huge problem if the stock mirror that came with the rig were up to QC par.

But it isn’t – which is why we were using the backup in the first place.

Here’s the issue: one side of the stock mirror is coated and one side isn’t – the coated side is reflected to the camera that’s mounted on the top of the rig.

This disparity seems to cause a difference in light between the two cameras, to the order of one stop (ie. the upper camera gets about half the amount of light as the horizontal camera).

Our stereographer, Sean White, also found that there’s a slight colour difference between the two cameras, and a mild fogginess to the stock mirror.

We plan to use this rig to shoot the implosion of a condemned sports stadium in HD. And we deal with high-profile broadcasters – we have to deliver high-quality footage (for them and, more importantly, for a worldwide audience).

So Sean grabbed the spare – which we bought in case we break the original one while filming on an industrial site in Salvador, Brazil for the explosive demolition series Blowdown – to see if it gave us more consistent picture.

It did – there’s only 1/3 to 2/3 of a stop difference between the two cameras, the colour is almost matching, and it’s fog-free.

Though none of us are sure why this is the case, we moved to film with the superior mirror (ie. the backup became the starter).

But while Sean was re-screwing it into the rig, it cracked.

The placement process is quite a balancing act – screw the mirror in too loosely (or mess up the gaffer tape), and it threatens to slide out the bottom when you position it at 45 degree angle.

Sean thought he had found the sweet spot for tightening, but he was used to adjusting the stock mirror … the backup shattered under a similar amount of tension (which makes us think the first mirror may contain more plastic, but that’s just a theory).

Needless to say the setback is disappointing.

Sean got in touch with 3D Film Factory. They won’t exchange the stock mirror for one that’s like the backup. But they will sell us another backup at a deep discount.

Granted, this rig is cheaper than most of the other ones out there, so we can’t expect the moon.

But considering how integral a working mirror is to the system, hopefully quality discrepancies and the finicky screw-in process will be rectified in the future.

Shooting a 3D documentary: building a mini beam splitter rig for close ups

Vision alert. So we’re thinking of designing our own mini beam splitter rig to shoot close ups for our first 3D documentary . Here’s why: as I’ve mentioned,we’re trying to sort out our B cam system using Film Factory’s 3D Indie BS Rig – this should hopefully work for the majority of our B cam shots.

But it isn’t the most portable system – something that will surely prove challenging on an industrial site, where the explosive demolition series Blowdown takes place.

For the odd close up of the crew loading explosives etc. in a condemned sports stadium in Salvador, Brazil, it’s painful to think about moving the whole rig and setting up just to get a shot or two.

And we’d like to avoid using a side-by-side rig  because it’s a mission (if not a mission impossible) to get the cameras close enough together to film these types of shots.

If there’s a way to build a mini beam splitter unit, one person could just move in and get this footage with way less trouble (ie. instead of two people to set up the full-sized rig, etc.).

As an added bonus, we could also use this system in a temporary pinch if the main B cam system happened to go down.

We bought an extra mirror anyway, in case the one that came with the Film Factory Indie rig system malfunctions mid-shoot … why not try and put it to use?

Our stereographer, Sean White, knows a machinist who may be able to help us build this mini rig we’ve envisioned.

We’d probably use Canon Vixias – smaller than the Sony EX1/EX3 combination we’re trying to make work with the Film Factory Indie rig – and rig it as an underslung system.

One camera would be positioned below (instead of above), and the spare mirror would be angled the opposite way as the one on the full-fledged beam splitter rig.

This rig would theoretically snap onto a tripod, and would achieve a small enough interaxial distance for us to get the close-ups we need without a mega hassle.

If any stereo, etc. issues arose, we’d correct them in post – theoretically a relatively small workload considering we don’t use tons of these types of shots in our shows.

At the moment, it’s just an idea – but seems fittingly par for this unchartered course.

Editing a 3D documentary: working with two audio channels in Cineform Neo3D

Looks like we’ll have to find a workaround for the audio issue we’ve encountered with Cineform Neo3D software in order to edit our first 3D documentary.

As I’ve mentioned, the 3D files that Cineform creates only have two audio tracks.

To capture ambient noise as well as a conversation between two subjects for the explosive demolition show Blowdown, we have to capture at least three channels (a boom mic and two lavs), sometimes four (camera mic).

Our editor, Brian Mann, has been in conversation with Cineform developers to see if we could find a way to edit with more than two channels.

They’ve been very prompt in replying and helpful.

But unfortunately it looks like there’s no way to edit more than two channels of audio using the current version.

There’s no particular reason why the program’s this way – it’s just a design factor that isn’t optimal for our specific post production needs.

As far as we’re concerned it’s the best high-end game in town, and otherwise it’s working great.

Cineform’s lead Mac engineer plans to add it to the list of things to add to their future release, First Light.

In the interim, we’ll have to figure out how to adjust our workflow.

3D beam splitter rigs for Sony EXs: filmmakers weigh in

It seems we’re not alone in the quest to find a beam splitter rig/camera system that will work as our B cam setup for shooting our first 3D documentary.

My previous blog outlining the issue has been posted on the Yahoo! Group thread P+S Technik 3D Stereo Rig + 2 Sony EX3, where there are entries from several people looking for information on how to make this – and similar systems – work for them.

Here’s our particular issue: we’ve been testing a Sony EX1 and a Sony EX3 mounted on a Film Factory 3D Indie BS Rig, but are having issues getting the cameras optimally positioned.

One alternative mentioned in the Yahoo! thread is a P+S Technik rig, but from what I gather it’s more expensive than the Film Factory Indie unit we’ve purchased.

Another up-and-coming alternative seems to be Alister Chapman’s “Hurricane” beam splitter rig, evidently designed specifically with Sony EX3s in mind.

(more…)

Editing a 3D documentary: Cineform 3D software audio challenges

We’ve fed footage from our 3D green screen shoot into post, where we’ve promptly encountered our first editing glitch. We’re running a trial version of Cineform Neo3D software to see if it will work for editing our first 3D documentary.

The reason we’re trying this program is that it allows for dual steam, which means each eye is at full res and in real time, so we can do convergence, colour correction and other editing in real time rather than having to render whenever we make an adjustment.

Cineform also works with Final Cut Pro, the editing software we normally use to cut 2D HD there’s no way to edit 3D in FC without a 3rd party programs, as far as we know.

Great for picture, but there’s a problem with audio.

The 3D files that Cineform creates will only have two audio tracks.

To capture ambient noise as well as a conversation between two subjects, we have to capture at least three channels (a boom mic and two lavs), sometimes four (camera mic).

And since Blowdown – the explosive demolition series we’ll be filming – is event-based, there’s no opportunity for ADR, and you can’t recreate most of the ambient sound in post.

(more…)

3D documentary filmmaking: why Sony EXs aren’t ideal for our beam splitter rig

A week of testing our B cam beam splitter rig system has revealed that the Sony EX1/EX3 duo we’re using with the Film Factory 3D BS Indie Rig aren’t ideal for shooting our first 3D documentary.

The issue isn’t technical – Alister Chapman reports using the same cameras successfully, and we were able to genlock the EX3 to the EX1 by connecting the EX1’s Y channel of the component output to the EX3’s genlock in connector, just as he has.

It’s logistical …the cameras are just too big and cumbersome for this particular beam splitter rig.

We’ve modified the rig so they fit better, but getting them aligned vertically is rough – the mics protrude and we’re still seeing the edge of the box and/or the bottom of the mirror when we use our Sony EX 5.8 mm lens (which has a 56-degree horizontal angle of view).

Wide shots are a must for Blowdown, the explosive demolition documentary we’ll be filming, so we need a system that will effectively capture this kind of footage – ie. we need to hit the sweet spot on the mirror, have the cameras vertically aligned and not see the rig when we use wide-angle lenses.

The alternative is enlarging the image in post to eliminate the part(s) of the shot that contain the rig, but that will degrade the quality, so I want to try and avoid this (especially since we’ll be blowing the footage up it to a certain degree already to facilitate convergence).

So, now we’re working with Canon Canada directly to get loaners of the XF305, which has just been released.

(more…)

Shooting a 3D documentary: review – Film Factory 3D Beam Splitter Indie Rig

Our crew’s spent the last week testing the B cam system we hope to use to shoot our first 3D documentary.

Here’s what we’ve learned about the Film Factory 3D BS Indie Rig:

Pros

1) Relatively affordable: rings in at $3,895 US plus shipping and handling (we also bought an extra mirror in case the first one smashes in the field. Don’t think we’ll find a second lying around at the condemned sports stadium slated for explosive demolition in Salvador, Brazil, where we’re going to be filming, and shipping one in would surely be a nightmare).

2) Robust but adjustable: the rig’s sturdy, so I think it will stand up well in the field. But luckily the structure isn’t rigid – we’ve had some difficulty lining our Sony EX1 and EX3 up properly (see: large and cumbersome … it’s a problem), so we’ve disassembled the rig, manually repositioned parts, and tightened them to try and accommodate the cameras.

Specifically, the aluminum rails are locked in with screws that can be loosened, adjusted, and locked back in. Without this flexibility we’d have no hope of effectively adjusting the heights of the cameras relative to the base rail (which we’re still working on. Argh).

Cons

1) Manual operation: It doesn’t have all the fine, automated controls that the higher-end feature film rigs do. It lacks motorized components, so factors such as interaxial distance and convergence have to be adjusted manually. In feature film production, it’s often one person’s job just to operate the remote to make these adjustments on automated units.

2) Heavy load: This is just something the crew’s going to have to get used to – 3D shooting demands so much more gear. But it’s still a downer. Total tally: the rig, a tripod, two mid-sized cameras, the nano3D recorder, the Transvideo Cineform 3D Monitor, all the sync cables, and battery. We think it may take two extra bodies in the field just to move all of these components around.

And the cameras are a whole other story … more to come on the Sony EX1/EX3 issue.

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.

(more…)

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.