360 visit to London's Chinatown

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This weekend BBC World Service’s Food Chain and Radio 4’s Food Programme presented a special programme on Chinatowns around the world.

We created a 360 degree video to allow viewers to step into London’s Chinatown and experience the tastes and smells of a Chinese supermarket and kitchen, with food writer Fuchsia Dunlop as guide.

The film is available as a 360 film on YouTube or Facebook, but it will look best viewed as VR film with a headset.

The film demonstrates 360 filming techniques for immersive journalism being developed by BBC NewsLabs/BBC R&D. It was directed and edited by film-maker Peter Boyd Maclean with Peter Passmore of Middlesex University technical advisor.

How the film was made

The film was shot using the GoPro Freedom 360 rig comprising six GoPro cameras shooting at 60fps at 4k. The cameras were positioned carefully to reduce post-production time.

We recorded separate sound on the presenter Fuchsia Dunlop using a lapel mic and a Marantz recorder.

The footage was stitched using Kolor Autopano, and then edited using Premiere Pro. The image of the tripod was removed using After Effects to create a full 360 film. It was created as a fast turnaround piece –it was filmed, stitched and edited in 5 days.

The detail

The film was shot in three locations:

  • Gerrard St (at the heart of London’s China town)
  • Inside a Chinese supermarket
  • A kitchen in a Chinese restaurant

Filming in Gerard Street

We have discovered that the optimum shooting position for the Freedom 360 rig for viewing on a VR headset without too much disorientation is around chest height.

But this creates stitching problems when filming in a busy place like Gerrard Street so we decided to raise the camera a few feet higher to reduce the time spent in post-production fixing the stitching issues.

Experience has taught us that when shooting with the multi camera rig it’s important to assess the issues that will occur in post-production and make a decision on how to shoot on that basis.

Filming in the supermarket

The supermarket presented a problem because it was a small space which was likely to create stitching issues. And Fuchsia’s full body needed to be covered by one camera but this wasn’t possible with the usual camera alignment.

Peter Boyd Maclean experimented with putting the rig at a 90-degree angle which brought one camera round to face forwards. He did this by altering the tripod fluid head and tilting the tripod so the camera was in position.

Unable to monitor the camera as the WiFi connection to the Go-Pro app didn’t work he had to guess from experience and make sure Fuchsia didn’t come too close to the camera.

Filming in the kitchen

The kitchen was another small space with a low roof. Fuchsia and the chef were standing opposite each other across the preparation table and the stove were to the left of the chef.

In the kitchen

Peter wanted to get the presenter and stove in one camera view again to avoid stitching issues . He repeated the technique of twisting the rig to get the camera into normal filming position. (It’s important to remember that we were filming 4x3 and not 16x9.) Again, some guess work was involved in judging the distance.

Before calling action it is important to remember to twist the camera sharply and to use a clapperboard or single handclap to help sync the cameras and separate sound.

At the end of the scene before the rig is moved to the next location, it is important to shoot a matt shot of where the tripod was positioned in order to patch it out later in post.

Post-Production

The shots stitched together without an issue and the new framing idea worked.

The next step was to sync the presenter’s audio to the rushes and then edit.

The tripod looked odd with the new camera angle - as though it had been left in shot accidentally. So after editing, we exported the shots from the master time line to remove the tripod in After Effects. It is important to ensure the shots are exported same as source to maintain high res quality. Bit rate should be between 25 and 50 bits

There are still lots of unexpected issues with new technology like this, and plenty of troubleshooting. For example, a black line appeared at the seam of the panorama when viewing in the headset. After some time, we discovered that this was probably caused a change in the pixel aspect ratio.

The pixel aspect ratio was reading 0.0889 on some shots when it should be 1.0. When this was changed in Premiere Pro the issue was solved.

The Future

For future 360 films, we will be concentrating on sound, spatial sound and head tracking audio which is very important to help create an immersive experience when viewing with headphones in the headset. We’ll also continue to test new cameras and improve work-flows.

Peter Boyd Maclean, Film maker
Zillah Watson, Editor, BBC R&D


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