LEGEND has it that exactly 100 years ago the budding film director Georges Melies accidentally transformed an autobus into a hearse when his camera jammed. Melies, a theatre magician by trade, had stumbled upon "stop motion", a fundamental trick of science fiction films.
By the end of the 1960s, though, big special effects movies seemed to have stopped moving. Stanley Kubrick's 2001 (1968) appeared to mark the end of the line rather than the start of a new era. The Hollywood studio system was in the doldrums, and the special effects units were among the biggest victims of the "downsizing".
So George Lucas was at a loose end. The producer/director's forthcoming Star Wars movie required some stunning special effects, such as strange landscapes and highly choreographed dogfights, but he reckoned no existing special effects unit could do them. So he set up his own unit specially for the film, and called it Industrial Light and Magic (or ILM).
The name said everything: it would be an industrial machine, working with light - the very stuff movies are made of to create magic on the screen. And out of ILM rolled an entire generation of blockbusters: not just the Star Wars space epics and the Indiana Jones trilogy, but other special effects mile stones such as Terminator 2, various Star Trek outings and Jurassic Park.
ILM managed to straddle the two very different eras of traditional craft and new digital technology. Its young team members were both resourceful and inventive. They would rescue ancient and neglected equipment (such as the Anderson optical serial printer) and resurrect almost forgotten skills. At the same time they were at the forefront of the digital revolution. As Steven Spielberg, one of ILM's most important "clients", once put it: "By exceeding my expectations time and time again, they have continued to be the pioneers in their field."
One particular goal was to develop new "motion control" systems, where they could program and repeat specific steps for models (such as the Star Wars fighter craft) and their lighting. These in turn would be synchronised with the movement of the film through the camera.
Another goal was to replace their meticulous hand built models with computer ones - such as virtual beasts that could only exist in the digital realm and as light on a screen.
Along the way too, lest we forget, they also happened to develop the most widely used image manipulation software ever.
The next time you load up Photoshop, look in the credits for two names: the Knoll brothers. ILM staffer John Knoll was a self taught computer expert and model maker since childhood, so he was naturally drawn to the special effects industry. His older brother Thomas was working on a doctoral thesis in visual systems for computers at the University of Michigan. They came up with Photoshop towards the end of the 1980s, and ILM made its first extensive use of the software for the underwater blockbuster The Abyss (1989).
Since then, ILM has been at the vanguard in designing other sophisticated digital tools, using them to morph, scan and create synthetic characters and cartoon humans (as in The Mask in 1994), and the plausible tornados of this summer's blockbuster, Twister (where the end of film credits for the effects seemed to last an eternity).
But while the latest software and hardware often achieve the impossible (compared with older techniques), the company isn't fixated by computers: it often mixes digital tricks with reliable traditional "hands on" effects, to create hybrids of the two. After all, what matters at the end of the day is the patterns of light captured in the studio cameras, and the patterns of light projected onto the screen.
As Dennis Murren (who received his eighth Academy Award for the visual effects on Jurassic Park) puts it: "In digital I'm working with many people who have four to 10 years' worth of experience and have gone through graduate school in computer science. In the half decade since The Abyss we've really come together. It's been an education on both sides - for me to learn about the new tools, for them to understand film making.
"I can bring a fresh viewpoint. I don't have the bias that a lot of computer folks do, who want things to be pure and perfect. In school they were trained to write bullet proof programs that could work perfectly over and over again. But in movies we're making one shot And that one perfect shot is all that counts.
Patricia Rose Duignan who worked at ILM for two decades in production and senior management and film journalist Mark Cotta Vaz have just written Industrial Light and Magic: Into the Digital Realm, a definitive account about how ILM became computerised. Several chapters concentrate on specific techniques used in films such as the extraordinary interaction between Bob Hoskins and his cartoon costars in Who Framed Roger Rabbit?, or the way they seamlessly blended Tom Hanks with historical footage or artificially created crowd scenes in Forrest Gump.
The book is probably outside the budget of most Lucas/ Spielberg fans, but it should be essential reading for anyone working in the film business or studying modern Hollywood, or serious Photoshop users. It's lavishly illustrated and well written, a highly informative account of this pioneering dream factory, which played very special tricks with lightbeams.