LAS VEGAS, NEVADA - NOVEMBER 2009: The end of 2009 is currently the planned release date for the latest filmed addition to the Sherlock Holmes canon, starring Robert Downey Jr. and Jude Law in an almost irreverent take on the story of Baker Street's most famous detective. Downey Jr.'s clumsy, tousle-headed, slightly risqué version of Holmes is far removed from the calculating, ice-cool character portrayed by the likes of Basil Rathbone and Jeremy Brett in the past, and yet somehow, it all works brilliantly.

Exterior filming for the new Holmes film began in early 2009 in suitably old-fashioned locations in Liverpool, London, Chatham, and Manchester, with Second Unit sound recordings being overseen by freelance sound mixer John Casali. His recent credits read like a shopping list of UK-themed Hollywood blockbusters, with work on two Harry Potter films and on the recent James Bond film prior to Sherlock Holmes. Having borrowed a SoundField ST250 microphone as an experiment for the first Bond film, Casali bought a more up-to-date portable ST350 system to capture on-set surround ambience when he worked on his first Harry Potter two years ago, and has been using it ever since.

Like all of SoundField's other microphones, the ST350 captures audio in the four-channel SoundField B-Format, an output-independent format from which phase-coherent audio can be derived in mono, stereo, M&S or 5.1 surround sound can be derived using proprietary SoundField processing, and all from a single lightweight, portable microphone.

"The ST350 has been brilliant for capturing the basic 5.1 beds that the post-production guys use to build up the surround mix from scene to scene," explains Casali. "It creates very realistic soundscapes. Sometimes I still can't believe it's all from one mic."

"I used the ST350 a lot on crowd scenes and in the Great Hall at Hogwarts on the Harry Potter films, and on Sherlock Holmes it's been great for capturing the sounds of the period horse-drawn carriages on the streets,"

"I use Altiverb a lot to capture the impulse response of acoustic spaces we're recording in, and the ST350 has been brilliant for that, too. Now, whenever we're working in a location with a recognizable acoustic, I take an impulse response, because you can use it to recreate the ambience later in post. It's very handy for realistic dialogue replacement in post-production."

With shooting complete on Sherlock Holmes, John Casali is already working on his next projects, together with his ST350. "When I first tried out the ST250, it was a bit of an experiment," he admits. "Then I purchased the ST350 and started using it more often and now I never leave for a job without it!"

John is currently working on both parts of the forthcoming 'Harry Potter and the Deathly Hallows'.