Sweeney Todd, The Demon Barber of Fleet Street, Warner Bros.’ $50m musical-thriller, directed by Tim Burton, re-tells the Victorian melodramatic tale of Sweeney Todd, a fictitious English barber who murders his customers with a cut-throat razor and, with the help of his accomplice Mrs. Lovett, turns their remains into meat pies. The film gained three Oscar nominations, won the Oscar for best achievement in art direction, and grossed over $152million worldwide.
London’s MPC (Moving Picture Company) was the sole VFX vendor on the production, which was shot entirely at Pinewood Studios. Of the 380 VFX shots that MPC tackled on the film, around 150 involved the use of The Foundry’s KEYLIGHT and FURNACE plug-ins on Shake to achieve a range of invisible effects. These included the seamless compositing of 360˚ CG environments with live action, classic digital set extensions, and a range of finessing work such as sky replacements.
“We use The Foundry’s tools a lot on projects such as Sweeney Todd,” says Marian Mavrovic, compositing supervisor at MPC. “Tim Burton’s films are noted for their quirky and often dark, gothic atmospheres, and Sweeney Todd was no exception. The original live action was desaturated, almost monochromatic, with diffused lighting, and all of our VFX work had to be precise to preserve this original look. As Sweeney Todd was shot on stage, we handled a lot of greenscreen footage and had to pull consistently clean keys that would allow our VFX compositors to do their work efficiently. KEYLIGHT is a very simple but highly effective tool for keying. It doesn’t take long to get the result you need.”
In the scenes of Sweeney Todd’s return up-river, only the ship’s deck, rigging and the actors, which Mavrovic calls the “foreground elements”, were shot for real against green. Everything else – the London skyline, atmospheric skies, waters of the River Thames, small boats, London Bridge, plus smoke and fog effects (“the background elements”) – was added later with the help of KEYLIGHT.
Sweeney Todd also features a number of 360˚ CG environments, which MPC created and then seamlessly integrated into the body of the film. In one such scene, the camera tracks completely around Judge Turpin and Beadle Bamford as they walk outside The Old Bailey towards a pub, where the judge pauses to observe his reflection in a window.
The foreground live action in this sequence comprised solely of the actors performing on the stage floor that was dressed just with cobblestones and lampposts, shot against greenscreen. Every other element in the scene, including The Old Bailey, the surrounding streets, the pub and the dramatic-looking sky, was generated in CG at MPC. The shot with the Judge’s reflection actually involved a mirror where the window should have been, with the greenscreen reflecting in the mirror.
Again the key’s struck using KEYLIGHT helped to achieve the precise integration of the live action foreground with the 360˚ CG background – work of such high quality that it gained MPC a nomination for Outstanding Created Environment in a Live Action Motion Picture from the Visual Effects Society.
“When we grade and composite greenscreen VFX shots, we like to break them down into three basic elements – the foreground, background, plus the mattes from the keys we pull,” says Mavrovic. “This gives us a lot of control during the compositing phase in making the foreground and background plates sit well together. Having the foreground element nicely separated gives you what you need to grade out any colour spill from the greenscreen, as well as dealing with general beauty grading of the foreground plate. KEYLIGHT is strong in helping to remove spill from an actor’s face and clothing or a prop. It has become a standard tool we use for spill suppression and was very useful for us on Sweeney Todd.”
Obviously, the devil is in the fine detail in delivering effective keys. Mavrovic believes KEYLIGHT is excellent when it comes to hair, and rates its ability to deliver soft-edge mattes for shots where the transitions between the background and foreground elements need to be smooth and yet detailed. “Combining hard and soft mattes can be an effective way to pull keys on more challenging shots,” he says. “Some of the plates had a narrow depth-of-field which meant that objects dropped out of focus quickly. But good quality keys allowed us to maintain this softness, and we then matched the defocus levels from the foreground to the CG background to create a seamless transition.”
To reduce noisy keys, compositors at MPC often degrain plates before a key gets pulled to get a cleaner result using the DeGrain plug-in from the Foundry's FURNACE collection. The ReGrain plug-in is amongst the tools used at MPC to reapply grain over the results. Mavrovic adds that MPC’s roto and prep department also use FURNACE tools such as WireRemoval, RigRemoval and DirtRemoval regularly to clean plates by removing wires, rigs and other unwanted objects.
“KEYLIGHT and FURNACE plug-ins are very valuable to us in our day-to-day work,” he says. “They are standard tools we use to tackle all sorts of challenges that come to us in the compositing department and they helped us a great deal on Sweeney Todd.”