Article: The Green Screen Adv of TATMR

Putting a Fun New Movie On the Right Track
Reproduced with permission of Joan Hutton of the Canadian Society of Cinematographers

“If you don’t photograph your subject well, it’s almost impossible to make it look good in the final composite, no matter how good the computer artists are.” — Robbi Hinds csc

By Don Angus
 
When Thomas the Tank Engine and his roundhouse of friends came rolling into Toronto last fall to make their movie debut in Thomas and the Magic Railroad, the producers went looking for Robbi Hinds csc to help make the magic work. The transplanted South African cinematographer has the reputation for knowing a thing or two about shooting for visual effects.
 
THOMAS (No. 1) and PERCY at the station. Photo: David Milne

Thomas and Percy at the Station

“I think the main reason I was invited to come on board was because of my background and experience in visual effects, particularly with green screen,” Hinds told CSC News shortly after the project wrapped. “I have done a lot of study and have kept up to date on the latest technologies in terms of lighting and the various facilities that are available in order to achieve the best possible mattes for computer-based digital compositing. I take a great deal of trouble to get that right.

“About 50 per cent of the work I did on Thomas was green screen, a little bit of blue screen, and the rest of it was work with the actors on conventional interior and exterior sets at Lansdowne Studio 24 East. Eight weeks of intensive shooting.”

The Britt Allcroft production of Thomas and the Magic Railroad, written, produced and directed by Thomas rights-holder Britt Allcroft herself, is the British enterprise’s first feature film after years of near-legendary success in the triple-B world of books, broadcasting and buy-me toys. If you don’t know who Thomas the Tank Engine is, or Percy, or Edward, or Daisy, then ask any kid — they all know the classic children’s television series and spin-off videos.

The motion picture, due to be released in North America in July, stars Alec Baldwin (The Hunt for Red October) as Mr. Conductor, Peter Fonda (Ulee’s Gold) as Grandpa, and Mara Wilson (Mrs. Doubtfire) as young Lily.

Hinds, who came to Toronto from Cape Town in 1994 after working extensively in Germany and Vancouver, did all of the green-screen work for Thomas, “and there are something like 320 shots in the movie that require digital composites. The trains in the show are miniature scale of 1:30, so the main reason for most of the green-screen work is to place the actors in the scale environment of the model trains and therefore to allow the illusion in the final result that the trains are not miniatures but life size.”

Because of the U.K.-originated Thomas the Tank Engine television series, “the model trains and many of the settings existed in London.” When it was decided that the production of Thomas’s first feature movie would be based in Toronto, the trains, sets and specialized camera rigs were brought over and set up at Lansdowne Studio 24 West under the experienced supervision of British cinematographer Terry Permane.

Hinds said: “Terry, who had been the director of photography for the train scenes right from the inception of the TV series, had over the years developed some specialized techniques and equipment, such as a computerized periscope camera rig which runs on rails above the miniature sets and is able to move around very freely and get some wonderful points of view.

THE PERISCOPE lens, created by Terry Permane, allows trackside filming up to a quarter-inch from models.

Terry Permane's Periscope Lens

“Britt brought over her team of British technicians — the model train engineers and mechanics, the set builders and decorators. Many sets were also built by Toronto’s Gajdecki Visual Effects. Building miniature sets is a highly specialized function; for instance, the miniature trees were made specially in London out of brass and then painted, and they look absolutely real.”

“The risk with this kind of work is that the composite can look like a cutout.”

Hinds said a lot of the principal photography and scenic work for the movie, which is set largely on the mystical Island of Sodor, was shot on the Isle of Man (in the Irish Sea). Paul Ryan, “who has done some excellent scenic and panoramic work,” was recruited from Los Angeles as DOP, and he was accompanied by a camera crew, key technicians and production personnel from Toronto. “On the Isle of Man they found scenery, villages and a train station that looked wonderful.

“What remained,” he continued, “was all of the green-screen work plus the rest of the principal photography on conventional studio sets — day and night interiors and exteriors — with the principal actors.

“That’s where I came in, and what Britt and producer Phil Fehrle were clearly looking for was the ability to photograph equally well both the conventional sequences and the more technical green-screen scenes which place the actors into the background plates shot previously — for instance, the model work by Terry Permane and some of the principal scenes shot by Paul Ryan on the Isle of Man. When I photographed actors for those scenes, I matched the look by carefully studying the direction of the key light, the intensities, the lighting contrasts, the colour balances and all of those things, to aid the illusion that it was all shot at the same time.”

He explained: “The risk with this kind of work is that the composite can look like a cutout. If it’s done well, it’s seamless and the audience simply believes that the scale is real. Throughout the production that was really my major challenge, to constantly study the footage that I was to match and at the same time have the artistic freedom to work with actors of the stature of Alec Baldwin and Peter Fonda and make them look good. What very often happens when one places a light that makes an object like a car look good, it doesn’t make a person who is next to or in the car look good. So there has to be a compromise found.

“I would often look at Terry’s work, where he had placed the key light perfectly for the object, and cheat it just very slightly so that it also works for the actor. Fortunately, the schedule had been intelligently planned so that most of the model shooting was working ahead of us. They actually overlapped us by three weeks, but this was fine because it allowed Terry and me to have a lot of dialogue while I was in pre-production.”

Hinds added that he was fortunate on this production to work closely with visual effects supervisor Bill Neil of Los Angeles, a seasoned effects cinematographer and one of the pioneers in the business whose recent credits include the features Supernova (2000), Tomorrow Never Dies (1997), and The Fifth Element (1997). “We were able to have terrific rapport on how to get it right, and I think the success of the visual effects is going to be largely thanks to his input and support.

“There are technical elements and rules to shooting green screen — green is generally preferable to blue when shooting for digital compositing — and there are two types of situations. One is when there is no direct contact between the actor and the background. The green screen can then be placed far away from the actor, and, for technical reasons, as far away as possible so there’s no possibility of any of the green light — which is necessary to achieve the matte — falling on the actor.

“There are technical elements in terms of optimizing the exposure difference between the actor and the background in order to get the best possible key. I used a variety of types of green screen and different types of lighting, including a system developed in Los Angeles. The new Flo-co fluorescent tube has a wavelength that is specifically compatible with both the screen and the green layer of the emulsion on the film. This was a tool I was able to use to great advantage to achieve the best possible mattes.”

MR. CONDUCTOR is played by Alec Baldwin. Photo: David Milne

Alec Baldwin as Mr. Conductor

The second type of situation “is where it is necessary for the actor to be in touch with the background, which makes it impossible to use green light. The same quality of light that’s on the actor has to illuminate the screen. Therefore, one uses a different type of green fabric or paint which will react well with tungsten light. And one has to be careful to eliminate dark shadows, which will not photograph green. The technical demands of getting a good key when an actor is right on top of the green screen are quite awesome.”

Three different types of film stock were used on Thomas, Hinds said. All the film that Paul Ryan shot on the Isle of Man was Kodak. He used a Moviecam Compact camera with Cooke and Angenieux zooms, Canon and Zeiss primes. Terry Permane’s stock of choice for shooting the miniatures with his two Mitchells and the periscope lens was Fuji F-250, and Hinds used Kodak Vision 500T and 200T for the conventional photography and “for all of the green-screen work I used the wonderful new SFX 200T film stock that Kodak engineered specifically for this purpose. We exposed close to 100,000 feet of it. And Bill (Neil) tells me they’re pulling marvelous mattes.”

“One always has to have the freedom and the ability to use one’s eye judgment.”

Hinds, who used two Arri 535Bs from William F. White, praised SFX 200T as “a reasonably fast film in which the emulsion has been engineered to produce the best possible results from green, blue and red screens. It addresses the specific wavelengths that you want for green screen work and it certainly does produce better mattes, providing that all other technical elements of one’s input are equal. You can’t get sloppy with this kind of work, ever.

“There is an adage in this business that anything can be ‘fixed in post’ these days, but it’s not quite true. If you don’t photograph your subject well, it’s almost impossible to make it look good in the final composite, no matter how good the computer artists are. It’s all time and money. It may be easy to say, ‘Let’s take a shortcut on the set,’ but it’s going to be a long-cut in post. An apparent saving in production will actually cost a large amount of money in post-production.”

For that reason, the DOP related, the production used an elaborate and expensive system of trial composites, “virtually a video studio,” to give director Britt Allcroft an on-set idea of what the composite was going to look like. “It also helped us a great deal in terms of scaling when we were dealing with train plates and getting the people to look right, often enabling us to make just little, precise adjustments in the size and position of the characters.”

On the Arri 535s, chosen partly because of their superior video-tap quality, Hinds used a set of three Zeiss variable prime lenses because he said they gave him the quality of primes with the flexibility of zooms — the ability to change the focal length infinitely from 16 to 30mm on the first lens, 29 to 60mm on the second, and 55 to 105mm on the third.

“You’re not giving up any of the quality that a normal prime would give you, but you’re getting the advantage of being able to size an actor, relative to your background plate, without moving the camera. You can simply just tweak it in. It’s a big advantage particularly when you’re 16 feet up in the air on a scaffold tower, which often we were.”

GRANDPA is played by Peter Fonda. Photo: Tom Collins

Peter Fonda as Grandpa Burnett Stone

Hinds explained that “frequently we were shooting down because, for instance, to put a person in a scene that was shot by a camera two feet away from a miniature train, you find that your camera has to be 65 feet away and maybe 20 feet up in the air. Bill Neil and his crew were meticulous in preparing detailed dope sheets on the background plates that specified all of the significant distances, lens focal lengths and settings, height off the ground relative to the subject, even where and what the key light was.

“Then, with some huge math by a specialist, all of these dope sheets were scaled up to the life-size scale that we were working to. The first thing on every setup was to set the camera according to that data. Sometimes it needed just a little bit of fine tuning, and this was the advantage of having the on-set rough composite — we could make slight adjustments in the focal length or move the camera a bit left or right or up or down.

“This is after all an artistic medium riding on technology. Very often, what is theoretically and technically right doesn’t quite look right. So one always has to have the freedom and the ability to use one’s eye judgment, to be able in the final analysis to utilize all this wonderful technology to help transfer the director’s creative vision faithfully to the screen.”

Four Toronto-based digital compositing houses are involved in the final realization of the images for Thomas and the Magic Railroad C.O.R.E. Digital Pictures, Gajdecki Visual Effects, Topix-Mad Dog, and Toybox. The “film-in film-out” scanning is being handled by Cine-Byte Imaging, and all the wet-lab processing is being done at deluxe toronto.

Hinds’s camera crew on Thomas and the Magic Railroad was Andy Chmura and Perry Hoffman, operators; Chris Alexander, first assistant; Courtney Graham, 2nd assistant; and Trevor Wiens, trainee.