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Wed 22 Apr 2009 04:00 AM

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The Curious Case of Benjamin Button

Much has been said about the VFX features In The Curious Case of Benjamin Button. However, this film could not have been realised if the images that were captured in production were not accurately transmitted to post. Maintaing a proper workflow for an all data capture was key to this project, says Stephen Roach of S.two Corp.

The Curious Case of Benjamin Button
The Curious Case of Benjamin Button
The Curious Case of Benjamin Button
The Curious Case of Benjamin Button

Much has been said about the VFX features In The Curious Case of Benjamin Button. However, this film could not have been realised if the images that were captured in production were not accurately transmitted to post. Maintaing a proper workflow for an all data capture was key to this project, says Stephen Roach of S.two Corp.

Following on from the success of David Fincher's Zodiac, his next project, The Curious Case of Benjamin Button, was designed from the outset to be captured from Grass Valley Thomson Viper cameras to uncompressed recorders. In this case, the images were recorded to uncompressed portable S.two Digital Film Recorders (DFRs).

This was a groundbreaking picture on many levels, not the least of which was for the fact that it was the first major Hollywood movie to use uncompressed data throughout the whole of principal and second unit photography.

When "Buttons" - as the film was called affectionately on set - was in the planning stage, S.two was asked to develop new technologies to provide a streamlined flow of material from set to post with principal photography slated for 150 days using two cameras most of the time. There was going to be a lot of material generated every day and on-set costs per hour and day were massive. Efficiency mattered most.

On Set

The on-set experience when using uncompressed 444 RGB data is very similar to a 35mm film one. Shooting data should have all the benefits of film plus added efficiency and productivity and this is what we sought to provide.

On set, there was a camera, two simple BNC cables to the recorder, a laptop, the recorder and the director's monitor.

On this film, we had less than an hour overall across 170 days of principal and many more of VFX. Not a single image was lost. This was an unprecedented record for any image capture device, chemical or electronic.

Thomson Grass Valley Vipers were used with Ziess digi-primes and digi-zooms. The camera was set to FilmStream 444 10 bit log and anamorphic (widescreen), which is an electronic anamorph using all of the sensor data provided by the camera. When un-squeezed from a 1920 x 1080 image, the picture was nearly 3K.

From the outset, ‘Buttons' was intended to have two principal cameras throughout the shoot. But there was more to it than that.

Data Capture

Data capture was undertaken by Fincher's video assist operator, Wayne Tidwell. Data capture helped us achieve overall operational efficiency by reducing the number of kit used and workflow complexity.

Operations were run from a single custom-made cart made by The Camera House (TCH), CA, a rental firm. From this cart, we had two DFRs, two eight-inch monitors, the TC/sync generators, a laptop for control, metadata management as well as Four lithium Ion 20 AH lightweight high power 24V DC batteries in case of power failure. In short, we were self contained and able to move at a moment's notice and stay powered when moving.

The cart had a sync and TC distribution amp so that we could supply genlock to the cameras and TC to as many as eight destinations, which came in handy as we had a couple of seven-camera days and many four or six camera days. An Ethernet network adapter was used for secure wireless access to each DFR and its DPX images as well. This allowed us to enter metadata from any where on the set.

Two Astro waveform/picture monitors were used by the DCE to give the DoP exposure details when asked.

The cart supplied live images and sound as well as instant playback for the director's monitor.

TC - Sound sync

A digital mono two-channel mix down was sent to each DFR from the sound mixer. This allowed sync playback on set for each take immediately and easy generation of sync dailies for editorial.

For Buttons, despite having three TC destinations or more, we decided to go for a single TC source and distribute that so that all TC requirements were met from one central location.

Colour Management

Part of the basic design criteria for S.two was the addition of colour looks applied to the output of the DFR. This was due to the nature of many Digital Cinematography cameras being in LOG colour space (and now in raw data). But just having a look was not enough. The look had to be meaningful so that it could be used further down the chain.

S.two, therefore, tied the Look Up Tables (LUT) to the metadata for each take. (LUT is a representation of what's in the actual data along with how that data should look). This allowed the DoP to change the LUT on a take-by-take basis as well as preview it on the live camera picture so he could use a LUT to make choices. More importantly, it helped maintain shot-to-shot consistency.

In this case, the cinematographer, Claudio Miranda, was able to make his own LUTs based upon actual test footage. He made LUTs using an Assimilate Scratch workstation and Iridas Speedgrade on set on his laptop.

In addition, the DoP could grab a frame anytime he liked, take it back to his hotel room and make new LUTs there and then with reference frames to send to post.

The problem, however, with most colour management schemes is that they are not tied to the data in any way and the viewing environment on set is not necessarily a calibrated one.

For this shoot, we selected TV Logic 24" HD-SDI monitors for providing pixel-for-pixel focus and viewing. We worked out an offset for the Mac laptops that we used for looking at the DPX frames against the TV logic monitors and did a rough grade with that. They provided the look and feel that the DoP was after.

The LUTs were recorded in the Take list and turned on automatically during the creation process of the dailies. In this way, the dailies matched the on set viewing and provided no surprises. The DoP and director had no control over the look of their picture during offline and test screening. In fact, Miranda ended up using only one LUT throughout the picture, although he had several available. Optical colour filters were used on the camera to provide balance to the colour.

The Viper sensors are not white balanced electronically, so the picture has a large green element. Using a mild magenta filter offsets the balance issue by knocking back the green and providing more blue through. This means that the blue and red get a boost without video amplification adding noise to the signal, giving a more natural and balanced look especially in the blacks and whites.

This contributed greatly to the overall look of the film. The LUTs were based upon using CC30 magenta filters but there were LUT for CC20 and 10. In low light situations, no filters were used and a LUT supplied for that. VFX

As the movie had a lot of visual effects, tracking became an issue during testing. Digital Domain was the main VFX house dealing with the makeup and ageing effects of the protagonist. It used in-shot infrared tracking systems for effects shots but as most of the film was shot on locations outside, IR-based tracking systems could not be used. Fincher, therefore, asked us for a witness cam system.

With this, two cameras would be used to establish a 3D overview of the scene that could be used to find out where in space the shots and VFX markers were. In order for this to be effective, these cameras had to be in sync with the principal photography cameras.

We quickly developed a system where we could record two uncompressed HD 422 signals into a single standard DPX frame on a normal DFR. This allowed the witness cams to have the same timecode, naming and metadata so that VFX was fully synced with the main production data. As it was shot onto D.MAGs, the same pipeline for archive could be followed for delivery of data direct to Digital Domain. Dailies and Post

All materials were shot to the D.MAGs on set and delivered immediately to post. Post, in this case, was not a third party post production facility.

In the data world, post is primarily done by the assistant editors on a shoot. The assistant would ingest the dailies for him, organise the shots, name them, add notes where applicable, and quality check the images so that they could start an assembly.

Often, he would have to sync audio and check timecode or re-apply TV. He would have to convert from 30FPS to 24, as well as cut the takes up and find the first and last frames. In all, it's a time consuming task to prep offline material for edit.

S.two was asked to find a way round that. For Zodiac, the edit company had come up with their own offline creation system which although good, was slow. It used the original DPX and an all data pipeline to create offline Quicktimes for FCP. It had to take in the LUTs and render the conversion to anamorphic.

We were asked to realise the potential of data and give the production crew instant dailies. To make this possible, we created a D.MAG player called i.DOCK for this project. A D.MAG is loaded from set and enables us to view the images immediately. More over, it uses all the metadata on the mag so one can turn the LUTs on and off automatically.

The i.DOCK also generates an FCP XML file that lists in FCP format all the takes, scenes and reel information that can then be imported into FCP. It also has the same interface as the on-set DFR allowing the assistant editor to fix any naming issues that arise such as mis-typing or naming, and he can add notes. The assistant does this before creating any dailies or archives so that any mistakes do not ripple through to the rest of the project.

The FCP XML file is imported directly from the i.DOCK to the FCP station. The FCP station has a video and an RS422 connection to the i.DOCK.

The XML file allows automatic batch capture of the entire D.MAG with all material in sync and sound and accurate TC as well as burnt-in LUTs and V-squeeze applied. All of the takes are named and marked automatically so the play-in is real time. The assistant editor then merely has to check the images while the transfer is happening.

Using a video interface has great benefits here. Besides time savings over a data pipe, it allows the images to be viewed as a quality control step.

The images were 23.98 HD-SDI widescreen. The ingest was in realtime, so the production had dailies every day, 30 minutes after the first mag had hit post. Fincher talks about his ‘hourlies', not dailies now.

This production also used an online secure dailies distribution system called PIX. The FCP station was set to make the H264 PIX images as soon as the first dailies hit the MAC. These were then uploaded to the secure server and used by the studio and production as a way to pass notes and view dailies - even when remote - from Hollywood.

Pix allowed the director to write notes directly onto the image as well as add comments. This was useful as so much VFX was to be done on this film.

We ended up with real time dailies and colour timed to the wishes of the director in the offline editorial system as well as on line in a secure viewing site.

Archiving was taken care of by A-DOCK, an in-house automated archive docking station that makes uncompressed data tape archives of the original data. More importantly, as we were using an all data pipe for this, we could provide automated data verification and archive verification.

In all, 538 D.MAGs were shot for this film, each the equivalent of 3000 feet of film. There were also 53 witness cam reels, each equivalent to 6000 feet. All of this needed to be archived.

One of the benefits of a fully tracked, all databased image capture and post system was instituted for The Curious Case of Benjamin Button.

In addition, an auto pull software was supplied to the production that took their offline EDL and then pulled just the image sequence in the edit on to the production server, automatically. It prompted the assistant editor to put the barcoded tapes required in order into the tape library and then went and got the data. This saved weeks of normal negative cut or video tape ingest and meant that the data did not have to reside on large servers anywhere.

In conclusion, it's often thought that Fincher could afford to do this because he has a lot of money. In fact, a saving of nearly 10% of the entire budget was realised over a film-acquired budget. The film's intent was very ambitious right from the start and the budget - although large - was tighter than for Zodiac. In fact, this film could not have been made using film origination or, in fact, on video. Data was the only way to realise the vision of this film and we see how this technology helped achieve the creativity of the director all the way from on set and in post.

Visual effectsFor approximately the first 52 minutes of the movie, when Benjamin appears in his 80s, 70s and mid-60s, he's not Brad Pitt in makeup. He is completely CG from the neck up, created by Digital Domain. The first shot is where Button sits at the table and drops the fork. The last is where he turns his head on the tugboat in the snow.

155 Digital Domain artists handled 402 vfx shots; 325 of which were head replacements. They worked from life-casts of Pitt and body actors to create three photoreal maquettes; then aged them to Button in his 80s, 70s and 60s. They created 3D computer scans of each of the three maquettes.

They shot scenes on set with body actors in blue hoods. They created computer-based lighting to match the on-set lighting for every frame where Button appears. Digital Domain also developed proprietary tracking and hair systems.

Francis 10 years ago

interesting use of an infrared camera. I have never really seen any applications for film before, other than stuff on Myth Busters or the Discovery Channel. I recently saw infrared cameras used in conjunction with a blower door on Planet Green as well.