His title at San Francisco and Los Angeles-based visual effects and production company The Orphanage is chief technology officer. But Stu Maschwitz is no gadget-obsessed geek.

'There are a lot of people who get off on the technical challenges; I'm not one of them,' asserts Maschwitz, who co-founded The Orphanage in 1999 after five years with George Lucas' Industrial Light & Magic.

'Solving technical problems is very much a distraction from the film-making process. But I love to solve creative problems.'

That preference served Maschwitz well in his role as visual-effects supervisor and second-unit director on The Spirit, the comic book-based action film from artist/director Frank Miller which opens in North America on Christmas Day.

While the Odd Lot Entertainment/Lionsgate production made extensive use of green-screen technology and CG imagery to create the kind of graphic look first seen in Sin City (the 2005 movie version of Miller's graphic novels, co-directed by Miller and Robert Rodriguez), 'aside from the sheer bulk of the work, there were very few unique technical challenges', Maschwitz reports.

'Every day there were creative challenges, which is what continued to thrill me about the job.'

Having worked as The Orphanage's VFX supervisor on Sin City, Maschwitz was already familiar with Miller - who, as well as making his solo directorial debut on The Spirit, wrote the screenplay based on Will Eisner's vintage comic-book series - and his visual style.

This time, however, Maschwitz and his colleagues, including director of photography Bill Pope (Spider-Man 2 and 3), helped put even more of that style on screen.

'Whereas in Sin City we may have been nervous about having, say, an entire scene with just pure black backgrounds, in this film we went for it,' he says. 'We've achieved a much greater level of visual simplicity in this film. We stood on the shoulders of giants in terms of 300 (another Miller adaptation) and Sin City, and we now trust ourselves and our audience to accept even more.'

Aside from handling his own creative challenges, as the project's overall VFX supervisor Maschwitz also oversaw visual-effects work from 10 other facilities including operations in Australia and Canada. The set-up made technological sense, he suggests, but required a good deal of organisation.

'Usually the person with my job title is working out of the studio lot or production house and doesn't have the kind of technology infrastructure we have at The Orphanage,' Maschwitz explains.

The company set up 'a sort of 'ops central' for all the work - we called it The Bunker'. It is the kind of system The Orphanage will be able to use on other projects, the facility's chief technology officer believes.

As for himself, meanwhile, Maschwitz, who is also an experienced commercials director, is developing his own screenplays and hoping for the chance to direct a feature. Making his second-unit directing debut on The Spirit, he enthuses, 'was about as much fun as one can have within the confines of the law'.